Phormiums often die from root rot, drought stress, transplant shock, winter damage, poor nutrition, pests, or disease. Check soil drainage and watering habits. Address specific issues. With proper care, Phormiums can bounce back, but replace dead plants with new specimens.
Phormium tenax is a plant species that is used as an ornamental plant. Phormium tenax is commonly called the New Zealand Flax plant/Harakeke.
Phormium is grown for its beautiful foliage. It is easy to grow this plant but beginners may experience some hurdles, let’s see what they are and try to find solutions for them!
Why is my Phormium going brown?
Phormium leaves turn brown at the edges when the plant lacks essential elements like Nitrogen. Phormium leaves also turn brown due to Sunburn. A severe mealybug infestation also turns the Phormium leaves brown.
Nitrogen deficiency in Phormium
Phormium plant’s leaves turn brown when the soil doesn’t have adequate Nitrogen in it. This situation is called Leaf margin necrosis.
You can’t help the brown leaves in any way. You can amend the soil to help the future foliage of your New Zealand flax plant.
Add liquid fertilizer like ‘Miraclegro’ or ‘Peter’s’ to the soil to increase Nitrogen quickly. Dilute the fertilizer according to the label instructions.
Tip: Get the soil tested before you amend it!
New Zealand flax plant is drought-resistant, so they don’t need much water to thrive. You just need to water the plant weekly once.
Giving your Phormium more water than it needs leads to waterlogged conditions. Phormium leaves turn brown in such conditions.
Check the soil with your fingers and water only when the top 2-3 inches of the soil is dry. Get a soil moisture meter if possible.
Phormium leaf spot
Leaf-spot disease in Phormium by a fungal pathogen. The infected Phormium plant leaves have brown/greyish spots with purple edges.
Cut off the infected leaves as soon as you spot them. The plant may recover eventually. Get rid of the infected plant to prevent a widespread infection.
Mealybug infestation in Phormium
If you see a white, waxy substance at the base of the leaves then your New Zealand flax is infested by Mealybugs.
Mealybugs are tiny insect pests that don’t get killed even by winter frosts. They love to feed on the leaves when the weather is warm.
Your New Zealand flax gets stunted as mealybugs feed on the plant. A severe mealybug infestation might kill your Phormium plant.
How to get rid of Phormium Mealybugs?
- Try to get rid of ants around your New Zealand flax plant as they deter the natural enemies of mealybugs.
- Spray water at the place of infestation to get rid of mealybugs naturally.
- Spraying insecticidal soap or horticulture oil on the infested plant works wonders.
- Destroy the plant if the infestation is severe.
Why is my Phormium turning yellow?
Phormium leaves turn yellow because of a bacterial pathogen Phytoplasma. The disease is called leaf-yellow. Phormium leaves may also turn yellow due to frost damage.
Leaf-yellow disease in Phormium
The leaf-yellow disease is caused by a bacterial pathogen called Phytoplasma which is transferred from a diseased plant to a healthy plant by flax plant hopper.
Infected Phormium plant becomes stunted and the rhizome gets killed by the bacteria. Leaves turn orange-yellow in color.
The disease may last for years if not months. Leaves yellow a lot in the growing season. You may want to dig up the plant and burn it to prevent the spread of infection.
Phormium frost damage
Phormium is frost-tolerant up to 20C. If the temperatures fall below this then the plant experiences frost damage.
Frost-damaged plant leaves discolor and become mushy. The plant looks like it’s dead. The plant should come back if you take good care of it.
Cut the dead leaves with a pair of sharp, sterilized pruners. Give your New Zealand flax some time to recover from frost damage.
Will my Phormium recover from frost?
Yes, Phormium can recover from frost. If the main stem and base are intact, new leaves should emerge by spring. Hold off pruning dead foliage until new growth appears.
With patience and care, even near-dead-looking phormiums often revive after frost. Resist replacing plants until you see whether fresh leaves regrow come spring—they can make a comeback!
How do you protect Phormium in winter?
You can protect your Phormium plants from winter damage by reducing the weight of the leaves. Do not let the plant go through winter all alone, help the plant.
Tie up the tuft of leaves to help reduce the weight of the leaves. This helps reduce frost damage considerably as I’ve seen.
My Phormium has collapsed
Once phormiums start severely collapsing from the base, they’re beyond saving and need replacement. Varieties with colorful foliage are most prone to fatal frost damage.
But with proper siting and care, phormiums can thrive for years before a base decline occurs. At first signs of inner stem collapse, plant new phormiums to avoid bare spots.
Phormium plants suffer from root or crown rot often due to overly wet soil. Stagnant moisture around the roots encourages fungal and bacterial diseases that cause rotting.
Improve drainage by amending heavy clay soils with compost or sand. Also, allow phormium crowns to dry out between waterings.
Remove any mushy, foul-smelling roots or plant tissue. Disinfect tools afterward to prevent the spread of disease. Water carefully, avoiding standing puddles.
If crown rot is severe, the phormium may need replacement. Maintaining good drainage and airflow will help prevent rot issues in the future.
Phormium leaves splitting
Split phormium leaves are usually caused by irregular watering leading to growth surges and split foliage. Prevent by maintaining even, consistent moisture.
Improve drainage in heavy soils. Trim off damaged leaves. With stable watering, new leaves should not split.
Big moisture fluctuations lead to rapid growth, resulting in the leaves literally splitting open. Prevent this issue by maintaining an even and consistent watering regimen, especially during the summer months.
Also, amend clay-heavy soils to improve drainage and aerate compacted areas around the plants. Once split, damaged leaves cannot repair themselves.
Simply trim off the affected foliage. With more stable soil moisture, new emerging phormium leaves should remain intact.
Phormium leaves drooping
Drooping leaves on a phormium are often a sign of water stress. Both overwatering and underwatering can cause phormium foliage to wilt and bend downward.
Check soil moisture – soaked or bone-dry soil indicates improper watering. Improve drainage in clay-heavy soils. Water thoroughly when the top few inches become dry, then allow to partially dry before watering again.
Drooping may also be due to transplant shock or disease. Look for root rot or pest damage. Exclude other causes before adjusting the watering.
With consistent moisture suited to its needs, a phormium will regain turgor pressure and the leaves should unbend.
New Zealand Flax White Fungus
The white, fuzzy things you see on Phormium are Mealybugs. Mealybugs are sap-sucking insects that appear as tufts of cottony, white mass in Phormium.
Mealybugs are common sap-sucking pests that can infest phormium foliage and roots. Look for white cottony masses on leaves and stems.
Heavy infestations cause yellowing or browning leaves. Remove mealybugs manually or use insecticidal soap sprays. Soak the ground with water to kill root mealies.
Ants may also be present tending the mealybugs for honeydew. Control ants to help eliminate mealybugs. Maintain vigorous phormium plants as they are less susceptible.
Check new plants carefully for pests before bringing them home. With prompt treatment at first signs, mealybug damage can be minimized before phormium health is impacted.
How to revive a Phormium?
To bring an ailing phormium plant back to health, first, identify the underlying issue.
- Brown leaves often indicate overwatering or nutrient deficiencies – improve drainage in wet soil and fertilize with a balanced plant food.
- Repot rootbound plants.
- Prune off brown spots which may signal fungal infection.
- Yellow leaves can result from frost damage or bacterial leaf-yellow disease – remove and destroy infected plants to prevent spreading.
- Protect phormiums from harsh winds and cold.
- Keep soil moderately moist but not soaked.
With care tailored to its needs, phormiums are resilient and can often recover from leaf discoloration and other common problems. But completely dead growth will need removal and severely damaged plants may require replacement.
Why won’t my Phormium flower?
Phormium flowers when the plant isn’t split. If flowers are important for you then do not split your New Zealand flax plant.
Give your Phormium a dose of Potash in the spring to encourage blossoms. If you decide to split your Phormium do this in dry weather.
Sometimes you just need to give your plant some time to restore its strength. Plants don’t blossom when they don’t have adequate energy/resources.
Happy Gardening 🙂