Flax plants (Phormium species) are versatile and hardy evergreens, well-suited to a wide range of New Zealand garden styles. Whether used for structure, colour contrast, or erosion control, flaxes offer year-round appeal with minimal maintenance. In this guide, we cover the best flax varieties for NZ gardens, how to plant and care for them, and tips to keep them looking their best season after season.
Establishing NZ flax plants (Phormium tenax and Phormium cookianum) and getting them to grow well is generally easy when you get a few of the basics right. This involves planting them in the right soil type, choosing the most ideal planting position, selecting the best variety, and ensuring the plants have the essentials to thrive. The Plant Company has the right advice to ensure success when you are growing flax.
Flax are very easy to grow, but you need to have the basics right. Choose a sunny spot with good drainage. The soil should be well prepared with organic matter added from either compost or sheep pellets mixed in. Feeding your plants in spring with Native Plant Fertiliser will replenish nutrients and keep them fed for 12 months. They should also be watered regularly during extended dry periods to keep them flourishing.
We have prepared specific articles to help you grow amazing flax plants:
Flax cope well with coastal environments provided they are not routinely covered in salt spray. Being constantly coated can result in leaf burning and the plant eventually failing. Similarly, if the soil is too saline, this can also prove detrimental to the plants and result in them becoming stunted. If you elect to plant in this environment, The Plant Company recommends ensuring the soil is well prepared with organic matter such as compost, and regularly water during dry periods.
Flax can be grown in pots and they look amazing when managed appropriately. Phormium Majestic Rage and Phormium Yellow Wave are often used as a larger specimen, Phormium Jack Spratt or Phormium Black Rage are used as intermediary sized specimens, while Phormium Sweet Mist or Phormium Tom Thumb are used as dwarf options.
Choose a pot that is no more than twice the size of what the Flax is currently growing in and that has plenty of drainage holes in the bottom. Fill the bottom of the pot to about 1/3 of the way up with potting mix. Do not use soil or compost when growing plants in a container and do not add fertiliser. The Plant Company potting mix has all the nutrients required to sustain the plant for the next 12 months.
Remove the plant from the container it is growing in by either pulling it free or by cutting the bag. We recommend cutting the bag, especially for larger grade plants, to minimise any chance of damaging the roots. If the roots are bound up, you can tease them apart if you want but this is not essential. The Plant Company does not advise cutting through roots, even if the plant is rootbound, as that injures this plant.
Place the plant in the pot, add more potting mix, and firm this around the plant using gentle pressure, then water well. They should be watered at least twice a week during hot weather and weekly or fortnightly during cooler periods.
The key to having an amazing Flax in a pot is to both keep it fed correctly (see the article, Best Fertiliser For Flax Grown In A Container) and avoid over-watering (see the article When To Water Flax).
The answer to this question depends on how much shade. In heavily shaded conditions, such as under a large, evergreen tree canopy, Flax tend to become “floppy” as the leaves compete with each other for light. At the same time, the leaves tend to have dark green tones and flowering performance is reduced. In full sun, they tend to be more compact, denser, with brighter colouring in the foliage, and better flowering. That said, they will perform well even if they get only four hours of direct sun per day, or high levels of speckled sunlight throughout the day.
Flax can grow in wetter areas, but within reason. Phormium tenax will happily grow in wetter and heavier soils, but not in boggy conditions. Phormium cookianum will not perform well in such conditions. For extremely wet (i.e., boggy areas) The Plant Company recommends Juncus or Apodasmia.
Flax thrive in full sun and naturally grow in open, sunny areas. Full sun helps to intensify the vibrant colors of their sword-like leaves, which range from green, yellow, pink, red, orange, burgundy, and bronze tones. Some varieties, particularly those with abundant white foliage, may benefit from partial shade during the hottest part of the day to prevent leaf scorch. However, most varieties can tolerate full sun without any issues.
Choose a full sun position or partial shade position with good drainage for your flax plant. The hole should be dug to at least 50-75% deeper and wider than the container the plant is currently growing in. A planting spade makes the hole digging a lot easier. The Plant Company recommends incorporating compost or sheep pellets into the soil to provide additional organic material, but this is not essential. Do not put fertiliser in the bottom of the hole, rather spread that on the soil surface after planting, and preferably do this when the plant is actively growing in spring.
Remove the plant from the container it is growing in by either pulling it free or by cutting the bag. We recommend cutting the bag, especially for larger grade plants, to minimise any chance of damaging the roots. If the roots are bound up, you can tease them apart if you want but this is not essential. The Plant Company does not advise cutting through roots, even if the plant is rootbound, as that injures the plant.
Now place the plant in the hole and make sure it is level with the soil surface before filling in around it. If it is above the soil surface, dig more out. If it is below, put in more soil and retest the level. Once the plant is set level with the soil surface, add more soil gradually and firm it around the plant using gentle pressure as you go. Scatter Native Plant Fertiliser across the soil surface after planting and then give the plant a good watering.
Flax look amazing when mass planted and are perfect for both banks, borders, entrances, mixed plantings, and for planting around larger trees and shrubs. The question about how far apart depends on whether the fully grown state has a gap between plants, whether they are to merge into each other, and finally the variety. By way of example, Phormium Platts Black grown to be distinct plants should be spaced at least 1.5-1.8 m apart. If they are to merge, a spacing of 1 m is recommended. For a variety such as Phormium Emerald Gem, space at 1 m for distinct plants, and 60 cm for merging.
Flax grow reasonably quickly and tend to double in size each year. The key is to start with strong and healthy plants at the outset. Be sure to check out the The Plant Company’s amazing Flax varieties.
Most Flax will reach about 1.2 m tall and wide, but this obviously depends on the variety and the growing environment. The Plant Company has put a lot of effort into determining how big each variety will grow in an unrestricted growing environment. Far too often we see people planting a garden too densely and then having to spend a lot of time trimming or removing plants later. This is something we want our customers to avoid, and we therefore provide size information for each variety listed so the planning can be right from the start. Be sure to check out our range and the detailed information that accompanies each of our Flax varieties.
Phormium cookianum, also known as Mountain Flax, are beautiful and versatile plants. They are known for their striking foliage and tall flower spikes. Growing Phormium cookianum is easy if you get a few of the basics right. They thrive in full sun, but can also tolerate partial shade. Heavy shade is not recommended as the plants tend to become “leggy” and have poor form. A free draining soil is essential as they become sickly and may die on heavy or constantly wet soils. Choose a spot sheltered from strong winds, especially if you live in an exposed area or provide some shelter while they establish.
Mountain Flax are best planted any time during autumn, winter, and spring. During these times the plants can establish before the heat of summer arrives. Water the plants regularly during their first growing season. However, once the plants are established, they are fairly drought-tolerant. The Plant Company recommends a fertiliser application using native plant fertiliser in spring and applying a layer of mulch around the plants to suppress weeds and preserve soil moisture. With these basics you will grow amazing Phormium cookianum plants.
Phormium tenax, also known as harakeke or NZ Flax, is known for its upright foliage, tall flower spikes, and hardy nature. Growing Harakeke is easy if you get a few of the basics right. Firstly, they thrive in full sun, but can also tolerate partial shade. Heavy shade is not recommended as the plants tend to become “leggy” and have poor form. While Phormium tenax prefers a well-drained soil, they can tolerate heavy and semi-wet soils. Ideally, they should be planted in a spot sheltered from strong winds, but they will tolerate wind once established. This NZ Flax is best planted any time during autumn, winter, and spring. During these times the plants can establish before the heat of summer arrives. However, once the plants are established, they are reasonably drought tolerant. The Plant Company recommends a fertiliser application in spring and applying a layer of mulch around the plants to suppress weeds and preserve soil moisture. If you get these few basics right, you will grow amazing Phormium tenax plants.
Placing mulch around Flax helps keep the soil moist and significantly reduces weeds. The Plant Company recommends an organic mulch is used as this breaks down over time to provide nutrients and improves the soil. It is also better for the environment than the plastic-based alternatives. Whatever type of mulch is used, it needs to be free draining so the soil can “breathe” and allow water to penetrate quickly and easily. Heavy rates of lawn clippings are therefore not a good option as they hold too much moisture. The Plant Company has three very good options for mulch. The first is coco fibre matting which is made from the husks of coconuts. The second is Earth Mat which is made from recycled paper. Both of these break down to become part of the soil within two years. The third is black plastic matting which will last 20 years or more. Whichever mulch is used, The Plant Company recommends stones, bark chip, or other similar products be spread over top for aesthetic purposes.
Compost is not considered an effective mulch as weeds germinate easily and it is only short lasting. It is, however, a very good method of adding organic matter to the soil and should be applied before the mulch is put down.
Phormium are fast-growing plants and can grow at 60 cm per year until reaching its mature size. The rate at which Phormium grows will vary depending on the climate, soil conditions, and the variety. For example, they will grow faster in warm climates than in cooler regions. They will also grow faster in well-drained soil than in poorly drained soil.
Only potting mix should be used when plants are grown in a container. Often people will try and cut corners and use soil or mixes that contain both soil and potting mix with poor results. The same applies to when plants are potted up with compost as it holds too much moisture. Soil also contains weeds and tends to become compacted in a container, hence why it is not used in this manner. The Plant Company has nursery grade potting media which is pre-loaded with the correct amounts of fertiliser and micro-nutrients to keep the plant sustained with nutrition and actively growing for the next 12-months. After 12-months, simply add a couple fertiliser tablets to keep the plant fed for the next 12-months.
Only potting mix should be used when plants are grown in a container. Often people will try and cut corners and use soil or mixes that contain both soil and potting mix with poor results. The same applies to when plants are potted up with compost as it holds too much moisture. Soil also contains weeds and tends to become compacted in a container, hence why it is not used in this manner. The Plant Company has nursery grade potting media which is pre-loaded with the correct amounts of fertiliser and micro-nutrients to keep the plant sustained with nutrition and actively growing for the next 12-months. After 12-months, simply add a couple fertiliser tablets to keep the plant fed for the next 12-months.
Soils rich in fertility and organic matter that are well-drained will produce amazing Flax. The soil should be well prepared with either compost or sheep pellets mixed in at planting, or spread on the soil surface after planting. It is important that the soil being planted into won’t restrict root growth and for this reason, tight-clay soils will impede root development, and generally result in stunted plants. All this said, the general rule is Phormium tenax for heavier and wetter soils (e.g., Dark Delight, Phormium cookianum for more arid spots (e.g., Phormium Emerald Gem).
Feeding your Flax plants in spring with Native Plant Fertiliser will replenish nutrients and keep them fed for 12 months. Liberal amounts of organic fertiliser can also be used. Do ensure that plants are watered regularly during dry periods to keep them flourishing.
Flax are best planted from mid-autumn until late spring. During this time, they can cope with the stresses associated with planting (root damage mainly) more easily than if they have to also cope with heat and moisture stress as well. They can be planted in summer provided they are well-watered, and the roots have plenty of growing media attached when planted. If watering is a challenge, The Plant Company advises planting any time from late-autumn through until early-spring. Make sure you have a good planting spade to make this job a lot easier.
A full sun position or partial shade position with good drainage will produce amazing Flax plants. They will grow well where drainage is less than ideal but will generally take longer to establish and can be susceptible to disease, particularly when young. In heavily shaded conditions Flax tend to become “floppy” as the leaves compete with each other for light. In full sun they tend to be more compact and have better flowering, particularly for the colourful varieties. They can tolerate wind, so shelter is not necessary.
Caring for flaxes is about making sure the plants are thriving. Our plant care articles provide the necessary details to give you the greatest chance of success. Afterall, there is nothing worse than putting the effort into planting for them to fail. Therefore, follow our advice and give yourself the best chance of success no matter if they are being grown in the soil or in pots.
The most important part starts with planting, and our article, How To Plant A Flax, provides sound advice on how to do this properly. So, let’s now assume your plant is growing well and you want to keep it that way!
Winter is the perfect time for mulching your plants. Organic matter such as compost or sheep pellets should be spread liberally around the plants and then overlaid with mulch. The Plant Company has three very good options for mulch. The first is coco fibre matting which is made from the husks of coconuts. The second is Earth Mat which is made from recycled paper. Both of these break down to become part of the soil within two years. The third is black plastic matting which will last 20 years or more. Whichever mulch is used, The Plant Company recommend stones, bark chip, or other similar products be spread over top for aesthetic purposes. The Plant Company does not recommend adding fertiliser during winter as this is better applied in spring so less is wasted. However, adding organic matter such as compost is quite okay.
Spring is the perfect time for fertilising the plants as they start to bounce into life. The Plant Company has fertilisers which have been specially blended for different plants and in this instance, our Native Plant Fertiliser will give them the correct boost and keep them fed for 12-months. A suitable alternative is our organic fertiliser which will also keep them well fed but they will require a secondary application in autumn.
Summer is when the plants need regular watering and this should be undertaken every second or third day on the hottest days. Plants that are establishing need particular attention as their root system will not have penetrated deep enough to secure consistent moisture yet.
Caring for Flax in autumn is about keeping the plants healthy. Foliar feeding using a liquid fertiliser can be undertaken during spring, summer, and autumn if you have time, but this is not essential if solid fertiliser and/or good amounts of organic matter have already been applied. If you think the plants need an extra boost or have some yellowing, however, a liquid fertiliser won’t hurt.
Plants should be checked for pest or disease issues during spring, summer, and autumn. If anything is looking unusual, refer to our articles under Flax Issues And Troubleshooting.
Providing the best fertiliser for flax (Phormium) is vital for ensuring the plants thrive. The correct fertiliser depends on whether the plant is grown in a pot or in soil, and getting this wrong can be disastrous for your plants. Our fertiliser articles provide the best advice about fertiliser for Phormium so you can achieve the amazing results you are after.
Flax are showy plants that require feeding to keep them looking amazing. A lot of articles have all sorts of advice on this subject which often requires multiple applications, so you use more of their products. The Plant Company prefers to take a simpler and more environmentally responsible approach. We believe the best organic option is The Plant Company’s organic fertiliser which is applied in spring and again in autumn and will keep them well fed. You can safely apply generous amounts of this fertiliser without risk of injuring the plants. More details about this organic fertiliser are provided with the product.
Flax grown in containers require different fertiliser to those grown outdoors in soil. In this instance the correct fertiliser to use is either container plant fertiliser or fertiliser tablets. Each of these will provide safe, sustained, and complete nutrition to the plant for the next 12-months. Using other types of fertilisers can be detrimental to the plant and may result in plant injury or death.
Foliar feeding using a liquid fertiliser can be undertaken if you have time but this is not essential if container plant fertiliser or fertiliser tablets have been used. If you think the plant needs an extra boost or has some yellowing, however, a liquid fertiliser application won’t hurt. A great benefit of foliar feeding is that it helps keep the leaves strong and lush as the nutrition is right where the plant needs it.
Flax require feeding to keep them growing optimally. The Plant Company’s Native Plant Fertiliser has been blended to give plants the boost they need and then sustained nutrition for the next 12 months. It is perfect for Flax.
We recommend the fertiliser is applied to the soil surface in spring just as the plants start to grow actively. More importantly, we advise that no fertiliser is placed in the hole at planting, but rather spread around the soil surface so it can wash through the roots as it releases. The Plant Company’s Native Plant Fertiliser ensures that nutrients remain in the soil around the plant rather than being lost through the soil profile to where the plant cannot reach it. This also applies to plants grown on sandy soils. The Plant Company’s Native Plant Fertiliser is therefore very environmentally friendly and longer lasting than most other products in the market.
Foliar feeding using a liquid fertiliser can be undertaken if you have time but this is not essential if Native Plant Fertiliser has been applied. If you think the plants need an extra boost or have poor colouring, however, a liquid fertiliser application won’t hurt. A great benefit of foliar feeding is that it helps keep the leaves strong and lush.
The soil pH refers to how acid of alkaline the soil is. Flax prefer a soil pH within the range of 6.2 to 7.5 which means they will tolerate both acidic and semi-alkaline soils. As the pH of the soil moves away from this optimum range, the nutrients the plant is taking up (or not taking up) through the roots changes. If the shift in pH is too far, this can result in deficiencies of some nutrients and toxic levels of others. In either case this can cause the plant to become sick or even die a slow death.
The best way to know whether the pH is correct for your plant is to do a test. The Plant Company has pH test kits available that are easy to use and only take a few minutes to get a result. Preferably this test should be completed before planting so any pH issues can be corrected without risking the plant. A pH less 6.2 should have sparing amounts of dolomite lime applied along with Native Plant Fertiliser. A pH above 7.5 should have small amounts of soil acidifying fertiliser applied. In both instances the fertiliser should be thoroughly mixed into the soil before planting. A retest of the soil pH should be undertaken after four weeks and small adjustments made again. If the pH is in the optimum range, just use Native Plant Fertiliser thereafter.
This series of articles answers many of the frequently asked questions about the New Zealand Flax, such as how fast they grow, their hardiness, and more!
Flax are fantastic for helping with erosion control. Flax are generally regarded as being semi-drought tolerant owing to their fibrous and deep penetrating root system. These are the perfect characteristics of plants for erosion control. Such properties also make them well suited for public spaces where they may be trampled from time to time and become exposed to prolonged dry and heat.
Flax are the perfect plants for riparian areas owing to their deep penetrating root system and ability to grow on damp and heavy soils. These are the perfect characteristics for riparian zones and they have the advantage of attracting birds. The most common flax used for riparian planting is Phormium tenax which is otherwise known as Swamp Flax. Phormium cookianum can also be used but planted on the more arid or steeper and drier areas.
Flax can take a heavy frost once established, though very young plants should be protected until they are at least 10 cm tall. Frost Cloth is a good option for protecting vulnerable plants if you are worried. Be careful to harden off recently purchased plants if you intend to plant these during winter and frosts are likely. Do this by gradually exposing them to the cooler conditions over a 2-3 week period or until such time as you think that a frost won’t damage them. The Plant Company recommends holding off planting until spring if you are at all worried that new plants might get frosted.
If plants do get frosted, they will generally recover. However, you will need to protect them from further frosts as this could kill them completely. Generally speaking, a good sized Flax planted in spring will cope with frosts the following winter.
Flax are fantastic for helping with erosion control. Flax are generally regarded as being semi-drought tolerant owing to their fibrous and deep penetrating root system. These are the perfect characteristics of plants for erosion control. Such properties also make them well suited for public spaces where they may be trampled from time to time and become exposed to prolonged dry and heat.
Flax only spreads naturally by seed dispersal. As the seed pods dry out, they are scattered to the immediate surrounds of the plant. Seedling survival rates in natural environments tend to be very low.
Harakeke, also known as New Zealand flax produces small flowers that are clustered on tall stalks that rise above the foliage in summer. They come in various colors, including red, orange, yellow, and green, depending on the specific Phormium cultivar. While not as showy as some flowers, Harakeke flowers have cultural significance for Maori as they are a symbol of purity and new beginnings.
The flowers can add a vertical element and a pop of colour to a garden. They also attract pollinators like bees and butterflies. However, it's important to note that not all flax varieties flower prolifically. Some cultivars are bred specifically for their foliage, and flower production can be minimal or absent. If you're interested in a flax that produces a good show of flowers, be sure to choose a variety known for its flowering.
Phormiums are regarded as hardy plants that can tolerate a wide range of conditions. Most varieties can withstand temperatures down to -5°C, though some can tolerate even colder temperatures. They also tolerate a wide range of soil conditions and are considered drought tolerant once established.
Flax is ready for seed harvest when the seed heads mature and turn brown. Cut the stems from the plant, bundle them together, and hang in a dry, well-ventilated place for 3-5 weeks. This allows the seeds to fully dry and mature within the pods.
To extract the flax seeds, thresh the pods onto a sheet so the seeds can be collected easily. The notion is to break open the pods and allow the seed to spill out. A threshing machine is recommended for larger quantities. After threshing, you'll need to clean the seeds to remove any plant debris. You can use sieves to separate the seeds from chaff.
Flax is not considered to be invasive. Flax grow as clumps and do not colonise larger areas easily. They do produce seed, but again, these do not enable the plant to spread in an invasive manner.
New Zealand has two similar, yet quite distinct species of flax; Phormium tenax and Phormium cookianum. The key differences between the two are the flowers, leaves, and where they are found naturally. Phormium tenax has rigid leaves and red flowers that are held upright, and is found naturally on the fringes of swamp and wetlands. Phormium cookianum has more arching leaves and yellow flowers that tend to be held in a pendulous manner. It also tends to grow in harsher climates such as mountainous areas as well as lowland areas.
New Zealand flax has a long history of being used for weaving and shelter by the indigenous people. These crafts continue to be kept alive today. It is also a food source for many of NZ’s native birds and fauna. Tui, Bellbirds, and Robins feed on the nectar in the flowers. Therefore, if you are wanting to attract fauna, or looking for a plant with fibrous leaves, New Zealand Flax is a great option. The are numerous varieties of flax, and The Plant Company has numerous amazing Flax varieties that are sure to meet your needs.
Flax, also known as Linseed, is a flowering plant cultivated for its seeds and fibres. Flaxseeds are a nutritional powerhouse, offering a variety of potential health benefits. Here are some of the reasons why flax is considered a beneficial addition to your diet:
It's important to note that while flax offers potential health benefits, it should be consumed in moderation as part of a balanced diet and healthy lifestyle. Flaxseed can interfere with the absorption of certain medications, so it's crucial to consult with your doctor before incorporating it into your diet, especially if you take any medications.
Adding NZ-native plants such as Phormium tenax into your garden delivers a vast range of benefits:
Māori used flax for a variety of purposes:
Mountain Flax, also known as wharariki, is a perennial plant endemic to New Zealand. There are two species, and both belong to the genus Phormium:
Mountain flax are popular plants for landscaping, both in New Zealand and around the world.
There are two commonly referred-to "bush flaxes" in New Zealand, depending on the context:
Both species are culturally significant for Māori and have been used traditionally for weaving, rope making, and other purposes. They are also popular ornamental plants and are used in landscaping projects around the world.
The common names for Phormium cookianum are Mountain Flax, Coastal Flax, Hill Flax, and New Zealand Flax. The Maori name for it is wharariki.
The common names for Phormium tenax are Swamp Flax and New Zealand Flax. The Maori name for it is harakeke.
Cordyline and Phormium are two genera of plants that are native to New Zealand. They are both evergreen plants with long, sword-shaped leaves. However, there are a number of differences between them:
Cordyline - Cordylines are typically taller and often grow as a small tree. - They have leaves that are arranged in a spiral pattern around the stem. - They produce flowers that are arranged in clusters at the top of the stem.
Phormium - Phormiums grow as a clump. - They have leaves that are arranged in a fan-shaped pattern at the base of the plant. - They produce flowers that are arranged in a spike at the top of the stem.
The key differences between Phormium tenax and Phormium cookianum are the flowers, leaves, and where they originate from. Phormium tenax has rigid leaves and red flowers that are held upright and grows on the fringes of swamp and wetlands. Phormium cookianum has more arching leaves and yellow flowers that tend to be held in a pendulous manner. It also tends to grow in harsher climates such as mountainous areas as well as lowland areas.
The flax-like plant in New Zealand is called Phormium, also known as harakeke or flax. It is a perennial plant that is native to New Zealand and Norfolk Island. It has long, sword-shaped leaves that can grow up to three metres long. The leaves are typically green, but there are also variegated varieties with yellow or white stripes.
Flax plants do have problems and disease issues from time to time. Therefore, it is important to understand the underlying issue(s) and have the remedies to fix the problem. The Plant Company have produced this series of articles to help you in the quest for answers to address common Phormium (flax) problems and disease.
Flax can suffer from a variety of pests. Mealy Bug, Scale Insect, Snails, and Aphids are commonly found on flax, but generally at low levels that don’t warrant spraying. That said, if pest levels are high and of concern, then a general insecticide or slug bait can be used for their control. Please always read the label before using any agrichemical.
Leaf death from the leaf tip on Flax is often caused by either over-watering or drought stress. Rapid onset can be caused by root rot and is discussed in the article, Flax Plant Dieback. Minor tip death can be trimmed off with scissors if it in unsightly, but the longer-term solution is to address the drainage or watering as relevant.
Another cause of tip death can be related to a lack of nutrition. This will be obvious through discolouring in the leaves, which can show as a difference between the younger and older leaves. Uneven colouring across the leaf is also a sign of a nutritional issue. If you think this is an issue, refer to our article, Best Fertiliser For Flax, to remedy the issue.
A common disease problem with young Flax is root rot. The tell-tale symptoms are yellowing of the leaves, which then turn brown, and collapse. This can happen during any season, and occur quickly. This is all resulting from the root system being progressively weakened by a root rot pathogen.
The best solution to this issue is good drainage and to treat plants early with a copper fungicide. The fungicide needs to wash into the roots to offer any control. The earlier plants are treated, the more likely control will be achieved. Please always read the label before using any agrichemical.
Grass weeds can really only be controlled in Flax via one of two ways. The first approach is to paint glyphosate onto leaves of the rouge grass. This requires a lot of patience but is very effective. The second method is to dig out the Flax, remove the weed inclusions, and then put the plant back. The Plant Company recommends following the advice in the article, How To Mulch Around Flax to reduce weeds returning.
Leaf spotting on Flax can be caused by Leaf Spot Fungus. This disease causes unsightly spots on the leaves which off start off yellow and eventually become brown as the leaf tissue dies. It is often a problem during warm, humid weather or where plants have limited air-flow around them. The solution is a copper fungicide, improving air-flow, or both. Please always read the label before using any agrichemical.
Holes in flax leaves are caused by NZ native caterpillars known as notch or window caterpillars. They will often chew a short section of leaf tissue from the rear of the leaf. This exposes the fibrous material in the leaf. They tend to move along the fibres rather than across them as this is an easier way to feed. Eventually the exposed tissue dies right through the leaf, to leave the characteristic “notch” or “window”.
Flax is one of the natural food sources for the offspring of these native moths, and damage is often at low levels. However, if you are spraying your flax for other insect pests with a general insecticide, this will also control these caterpillars. Please always read the label before applying any agrichemical.
Some common problems that can affect flax include:
If the new growth on your Flax has been killed or damaged by frost, trim off the damaged leaves after the risk of frost has passed. Frost cloth or a blanket may be used to afford protection from further frosts. It is important not to cut off the frosted growth until the risk has passed as this growth, albeit ugly, is helping to shield the plant from further damage.
New shoots tend to be more prone to frost damage than older ones. For this reason, The Plant Company does not recommend applying fertiliser of any kind to plants between mid-autumn and late winter as this can create softer shoots that are more susceptible to frost.
A stunted flax may be caused by a bacterial infection. The bacteria is spread by native insects and causes the plant to not only become stunted, but develop yellow-orange tones in the leaves. The plant will eventually start to collapse and die, even if the inner leaves look normal. There is no control for this issue for the home gardener. The best option is to remove the affected plants and burn them so the disease does not spread further.
There can be many reasons why a flax begins to die and it is often an iterative process to determine why. The most common reasons are presented below and organised from most likely to least likely based on The Plant Company's experience.
Flax will fail to flower if they have endured stress, as the stress usually causes the flowers to abort. For example, Flax grown in heavy shade will often not have the reserves to put energy into flowers. Similarly, if plants have endured too much drought stress, they will often not flower, particularly if this occurred during the time the plant starts to initiate flowers. Presuming the stress has been alleviated, normal flowering should resume.
Flax can recover from frost damage, but the extent of the recovery will depend on the severity of the damage. If the frost has only damaged the leaves, the plant should recover on its own. However, if the frost has damaged the growing tip of the plant, it may take longer for the plant to recover, if at all.
Yellowing flax leaves and stunted growth may be caused by a bacterial infection. The bacteria spread by native insects and causes the plant to become stunted, develop yellow-orange tones, and the start to collapse. Inner leaves may continue to look normal but will eventually succumb to the disease. Unfortunately, bacterial infections are difficult to control in home gardens. The best option is to remove the affected plants and burn them so the disease does not spread further.
Watering Flax correctly is an important part of growing amazing plants. Importantly, making sure your Phormium gets enough water without being over-watered is paramount. Our articles provide advice and guidance on this subject.
Phormium cookianum has adapted to cope with semi-arid and mountainous environments, hence its common name, Mountain Flax. It therefore can cope with drier conditions much better than Phormium tenax. The Plant Company recommends watering at least 1-2 times per week during summer, and only during extended dry periods during winter. If plants start to droop, you need to water immediately. The Plant Company advises watering in the morning or in the evening for water conservation purposes.
Please note that most of the varieties sold are a cross between Phormium cookianum and Phormium tenax, so should be watered more frequently. These are typically the more colourful varieties such as Phormium Yellow Wave, Phormium Black Rage, and Phormium Veneer.
Phormium tenax has adapted to cope with near swamp like conditions, hence its common name, Swamp Flax. Despite its name, it can cope with periods of dry reasonably well. However, in such conditions, growth slows and this is generally not desirable. The Plant Company ] recommends a generous watering every third day during summer, or every fifth day if the soil is a bit heavier. If plants start to droop, you need to water immediately. The Plant Company advises watering in the morning or in the evening for water conservation purposes.
Flax require good levels of soil moisture during dry periods to stay fresh and keep growing actively. They are generally regarded as being tolerant of dry periods but will benefit from watering both during establishment and during the dry periods. The Plant Company recommends a generous watering every third day during summer, or every fifth day if the soil is a bit heavier. If plants start to droop, you need to water immediately. The Plant Company advises watering in the morning or in the evening for water conservation purposes. Please be sure to read the article, Flax Diseases, as over-watering can have unintended consequences!
During extended dry periods Flax may stop growing to preserve themselves. This is clearly not desirable if you are still wanting them to grow. They will start growing again once rain or water is provided and as long as they have not been allowed to totally desiccate.
If the Flax is being grown in a pot, watering 2-3 times a week during summer and once a fortnight during winter is the general rule. This will depend on how hot the growing environment is and the size of the plant, of course.
Propagating flax plants is a relatively straightforward process when you have the right advice. They are easily reproduced and our articles give you the best chance of doing this successfully and efficiently.
Flax are easily propagated by division and by sowing seed.
Propagation By Division Established plants are simply broken apart with roots still attached. This task is usually undertaken in autumn or winter, with the plants potted up using growing media for several weeks before planting out again. Take care not to make plants too small as they must have plenty of roots to successfully re-establish.
Propagation By Seed Flax are also easily grown from fresh seed. Simply place the seed onto well-draining potting mix, cover with a fine layer of vermiculite or sifted potting mix, and place in a warm spot. Ensure the tray does not dry out but also make sure the soil is not sodden. The seedlings should emerge in 2-3 weeks and be ready for transplanting at week 8.
Decisions about when to trim a flax, how to cut them back and how hard, and even how to do this task can be daunting for the novice gardener. The Plant Company have produced this series of articles to provide advice for how to trim flaxes so you can manicure your plants with confidence and success.
Most Flax varieties will sprout new shoots when cut right back, even close to ground level. However, this relies on the plant having heathy shoots at the outset. This activity is best undertaken during summer using secateurs. Please note: Flax grown in shade environments or suffering from disease or nutritional deficiencies may struggle to re-establish when cut back severely. The Plant Company does not recommend cutting plants any lower than 10 cm above the ground to improve the chances of this procedure killing the plant.
Flax are generally only trimmed to remove unsightly leaves or cut back more aggressively to rejuvenate or control a plant. This is best done during spring or summer when plants are in active growth. Aggressive trimming usually involves cutting plants back to 5-10 cm above the soil level. Flax are very forgiving plants and even if you get the trimming wrong, they will generally recover! Unfortunately, there is always a risk of plants dying after such aggressive trimming. This will sometimes occur if the plants were diseased or suffering nutritional deficiencies ahead of trimming. In these cases, the plants just don’t have the energy to resume active growth.
Light trimming can involve cutting the brown tips off leaves, cutting out yellow or sickly-looking leaves, or even thinning out the clumps. This can be done at any time. If dead leaves don’t pull off cleanly or are tough to pull, simply cut them off at ground level.
Flax can benefit from being cut back every two to three years. This helps to maintain the plant's shape, promote new growth, and prevent it from becoming overcrowded. Here are some specific reasons why you might want to cut back your flax:
The best time to cut back your Phormium is in the late winter or early spring, before new growth begins. After you have cut back your plant, be sure to water it well and fertilise it with native plant fertiliser. This will help the plant to recover from the pruning and promote new growth.
An overgrown Flax can be brought under control by either trimming it or thinning out the clump. The easiest way is to trim the plants by far, but the longer-term solution may be to thin out the plant. Flax can be cut right back to about 10 cm above ground level. However, this relies on the plant having heathy shoots at the outset. This activity is best undertaken during summer using secateurs. Please note: Flax grown in shade environments or suffering from disease or nutritional deficiencies may struggle to re-establish when cut back severely. The Plant Company does not recommend cutting plants any lower than 10 cm above the ground to improve the chances of this procedure killing the plant.
Thinning out Flax involves putting a spade between the shoots and either levering out or cutting them off below soil level with a sharp spade. Doing this will thin out the plant and take it back to a few stems. It may look a tad unsightly after this procedure, so you may want to consider cutting it back as described earlier.
Flax can be trimmed at any time of the year, though summer is the time recommended by The Plant Company for any aggressive cutting back. The plants sprout from the base and at this time of they will bounce into active growth quickly. Light trimming to remove unsightly foliage can occur at any time of year, as can pulling out the dead leaves. If they don’t pull off cleanly or are tough to pull, simply cut them off at ground level.
Choosing a flax variety that works for you can be challenging given the sheer number that are available. Working through the different varieties, their sizes and preferences, and so on, can take considerable time. The Plant Company’s series of short articles aims to offer concise and easy to follow advice and recommendations so you can determine the variety for your needs.
The Plant Company has a range of Flax varieties and the choice depends on the what the plant is to be used for. The most common uses are for mass planting, adding to a mixed planting, or for planting around outdoor living areas such as pools and the like.
The Plant Company recommends the following varieties based on their popularity and suitability for different uses:
Be sure to check out The Plant Company’s amazing range of Flax varieties to find the one(s) that will suit your needs.
Phormium tenax 'Black Rage' is a stunning, smaller variety of Flax, and is known for its dramatic, almost black foliage. Some of its key characteristics include:
Appearance: - Dark, smoky black, sword-like leaves. - It has a compact and tidy habit, typically growing to around 80 cm (32 inches) in both height and width.
Growing Conditions: - Thrives in full sun which gives the most intense leaf colouring. - Adapts well to most New Zealand soil conditions as long as they are well-drained, including poor soils and coastal environments. - Handles wind, frost, and cool climates.
Care: - Requires minimal care once established. - Water during hot and dry periods but avoid overwatering. - Apply native plant fertiliser in spring to encourage optimal growth, but it's not essential. - Remove spent flower stalks and dead leaves to improve the appearance.
Uses: - Ideal for borders, edging, mass plantings, growing around pools, or as a specimen plant. - It adds a touch of colour and texture to a garden. - Is well-suited to growing in a pot.
Phormium tenax 'Black Rage' is a low-growing and easy-care flax variety that brings dramatic colour to a garden to afford wonderful contrasts.
Phormium tenax 'Dark Delight' is a popular New Zealand Flax variety owing to its dramatic, dark foliage and great form. A summary of its characteristics include:
Phormium cookianum 'Dwarf Green' and Phormium 'Emerald Green' refer to the same plant. The names have simply evolved over time. This variety is known for its bright green, upright foliage, and compact growth habit. This low-maintenance flax is a popular choice for gardeners due to its adaptability and great aesthetics:
Appearance: - Vibrant green, sword-like leaves that grow upright from a clumping growth habit. - Reaches a mature height of around 75 cm (30 inches) and a spread of 60 cm (24 inches). - Produces yellow flowers on tall stalks during spring that attract birds.
Growing Conditions: - Prefers full sun to part shade but tolerates a wider range of light conditions. - Can adapt to various soil types as long as they are well-drained. - Tolerates coastal environments, wind, frost, and drought once established.
Care: - Requires minimal care once established. - Water regularly, especially during hot weather, but avoid waterlogging the plants. - Apply native plant fertiliser in spring for optimal growth. - Remove spent flower stalks and dead leaves for a tidier plant.
Uses: - Ideal for borders, edging, mass plantings, growing around pools, or as a specimen plant. - It adds a touch of colour and texture to a garden. - Is well-suited to growing in a pot.
Phormium cookianum 'Dwarf Green' is a low-growing and easy-care flax variety that brings a touch of beauty to a garden.
The list of Phormium that The Plant Company has cataloged, worked on, propagated, included in garden designs, and marketed is extensive. Our database of Phormium varieties is listed below:
Phormium tenax 'Jack Spratt' is a charming, dwarf variety of flax, and is known for its compact size and vibrant, dark-coloured foliage. Some of its key characteristics include:
Appearance: - Features narrow, sword-like leaves with a rich reddish-brown or dark burgundy colour. - Reaches a mature height and spread of around 60 cm (24 inches). - Produces yellow or orange flowers on tall stalks in summer.
Growing Conditions: - Thrives in full sun but also tolerates partial shade. - Prefers well-drained soil but can adapt to various soil types if they are free-draining. - Tolerates coastal conditions, wind, frost, and dry periods once established.
Care: - Requires minimal care once established. - Water during hot and dry periods but avoid overwatering. - Apply native plant fertiliser in spring to encourage optimal growth, but it's not essential. - Remove spent flower stalks and dead leaves to improve the appearance.
Uses: - Ideal for borders, edging, mass plantings, growing around pools, or as a specimen plant. - It adds a touch of colour and texture to a garden. - Is well-suited to growing in a pot.
Phormium tenax 'Jack Spratt' is a low-growing and easy-care flax variety that brings a touch of beauty and dramatic colour to a garden.
Phormium 'Sweet Mist' is a variety of flax prized for its bronze-coloured foliage and dwarf stature. This low-maintenance flax is ideal for gardeners with limited space or those seeking a striking accent plant.
Appearance: - Features narrow, arching leaves in a stunning bronze colour. - Grows compactly, reaching a mature height and spread of around 40 cm (16 inches). - May produce red flowers on tall stalks in summer, but the main attraction is the foliage.
Growing Conditions: - Prefers full sun to part shade but tolerates a wide range of light conditions. - Thrives in well-drained soil but can adapt to various soil types if they aren't constantly wet. - Tolerates coastal environments, wind, frost, and some drought once established.
Care: - Requires minimal care once established. - Water during hot and dry periods but avoid overwatering. - Apply native plant fertiliser in spring to encourage optimal growth, but it's not essential. - Remove spent flower stalks and dead leaves to improve the appearance.
Uses: - Ideal for borders, edging, mass plantings, growing around pools, or as a specimen plant. - It adds a touch of colour and texture to a garden. - Is well-suited to growing in a pot.
Phormium 'Sweet Mist' is a low-growing and easy-care flax variety that brings a touch of elegance to a garden.
Dwarf flaxes are popular choices due to their compact size and ease of care. The Plant Company considers a dwarf variety to be less than 70 cm tall. A list of the common varieties with their heights and leaf colour is presented below:
NZ has a few red varieties of Flax. The most common and their corresponding mature heights are presented below.
Phormium 'Emerald Gem', also known as Dwarf Mountain Flax, is a popular cultivar of the New Zealand native Phormium cookianum (Mountain Flax) prized for its compact size and vibrant green foliage. Here are some of its key characteristics:
Appearance: - Bushy and compact, growing in clumps with arching, sword-like leaves. - Striking lime green coloured leaves. - Typically matures to a height of 60 cm (24 inches) and a spread of 70 cm (28 inches). - In summer, it produces green-yellow flower spikes with red stamens, adding a touch of interest.
Growing Conditions: - Prefers full sun but can tolerate partial shade. - Adapts well to various soil types, including poor soils, but prefers well-drained conditions. - Requires moderate watering, especially during the establishment period. Once established, it is drought tolerant. - Tolerates frost and coastal conditions.
It is commonly used in: - Borders and mixed plantings. - Grown in containers where it provides a vibrant accent on patios or balconies. - Creates a stunning effect in larger garden spaces with a mass planting. - Provides a contrasting element to the rocks in a rock garden.
Phormium 'Emerald Gem' is a versatile and low-maintenance plant that offers year-round appeal with its lush green foliage. It thrives in various conditions and is suitable for diverse landscaping applications.
The Plant Company considers Phormium cookianum to be the hardiest of the Flax varieties. We base this off the survival rates following planting, and the lack of issues in the nursery. Phormium Jack Spratt, Phormium Emerald Gem, and Phormium Surfer are also very hardy.
The toughest flax is Phormium tenax, also known as New Zealand Flax or Harakeke. It is a native New Zealand plant that is known for its ability to thrive in a wide range of conditions, including cold, wind, and coastal environments. It is also relatively low-maintenance and easy to care for.
Phormium cookianum, also known as mountain flax or Wharariki, enjoys widespread popularity amongst gardeners and landscapers for several reasons:
Visual Appeal: - This New Zealand native features long, sword-like leaves that grow in a graceful arching form. The leaves come in various shades of green, some with reddish or bronze tinges, adding vibrant texture and color to any garden. - During summer, Phormium cookianum produces tall flower spikes in shades of yellow, orange, or red, adding another layer of visual interest to the plant.
Adaptability and Versatility: - It can tolerate a wide range of soil types, including poor soils and coastal areas. Additionally, it adapts well to sun or partial shade, making it suitable for various garden settings. - Once established, Phormium cookianum requires minimal watering and care, making it a great choice for busy gardeners. - This versatile plant can be used in various landscaping applications, including: - Its striking appearance makes it a stunning focal point in borders or containers. - Mass planting creates a bold and dramatic effect. - The extensive root system helps hold soil in place, making it suitable for slopes or banks.
Cultural Significance: - Phormium cookianum has cultural significance for Māori, whereby, its fibres were used for weaving various items like baskets, clothing, and mats.
In summary, Phormium cookianum is popular due to its unique and attractive appearance, adaptability to various conditions, low-maintenance needs, versatility in landscaping, and cultural significance in New Zealand.
These short articles provide some insight into how you might use Flax plants in different situations and what you might pair them with.
Flax owe their popularity to not just their aesthetics, but also to their versatility. They are commonly mass planted on banks, used to border paths and gardens, or included where a hardy plant is desired. They are well suited to planting around living areas, pool, and barbecue areas where they provide a fresh or colourful appeal is desired. The arching foliage is fantastic for providing elegance and texture to a planting. The Plant Company often uses them to accentuate an entrance, soften a bland wall, or to bring colour and vibrance to an area. They can be included in most garden styles with ease and make for an exciting addition. However, to get the most impressive shows, they do need to be mass planted. Explore The Plant Company’s range of Flax varieties to find the one(s) that will suit your design needs!
A wide range of plants can be grown with Flax. The Plant Company often recommends using Westringias and Astelias to bring in different colours, textures, and heights for mass plantings. Specimen trees such as Flowering Cherries and Maples are often used with dwarf flaxes. In this instance the flax serves to accentuate the specimen tree and provide elegance in their own right. The good thing about Flax is that they are versatile and blend easily with most plant colours and textures in a subtle and non-overpowering manner.
Whether you need assistance finding the plant you’re looking for or you simply want to know more about who we are and what we do, we invite you to get in touch with us today. A member of The Plant Company team will get back in touch as soon as possible.
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