Tree mallow (Malva arborea) Care Guide
Some consider it weed, but it's way more than that; the tree mallow has been considered a medicinal plant for ages, the leaves and flowers of some species are edible, and tree mallow tea is delicious. Whether in pots, garden beds, or flower borders, this plant seems to grow anywhere, and this ability makes the tree mallow very easy to grow. Standing at 15 - 61 cm tall, with pink, red, and whitish veined flowers, this is a gorgeous plant to add to a garden.
Quick Care Guides
Water and Hardiness
The tree mallow can grow under a broad range of temperature conditions, with bushier varieties usually able to handle warmer temperatures. this is a hardy plant, able to withstand a winter that drops down to -40 ℃. Some varieties, like the Tree tree mallow, can handle drought well once established, and will burst back into life when the rains return.
The tree mallow generally requires full sun exposure. It may thrive under partial shade, but this will negatively reflect on its blooms. A plant that is shaded will produce fewer flowers, so try to provide at least six hours of full sun a day. If provided with enough sunlight, your tree mallow will not need to be staked.
The tree mallow is not picky about its growing substrate. It can handle both clay and sandy soils and will adapt to most gardens. It doesn't necessarily require rich organic soils, and fertilizers are not a must. It will grow in neutral soil, but most will thrive if the soil pH is around 7.0.
plant your tree mallow in late summer or early fall. If planting in pots or in the garden, mix in some organic compost to regulate water retention. The tree mallow is easily grown from seed. Choose a location that provides well-draining but moist soil and full sun. Sow shallow, cover the seed with a light soil layer, and keep the substrate constantly moist until germination. Pinch back new-growth tips when they reach about 30 cm to stimulate more compact growth.
The tree mallow is a fairly drought-tolerant plant once fully established. Weekly watering is required only during its first year. After this, your watering regime can be reduced to once every 10-14 days. Alternatively, water an established tree mallow only during its growth and flowering periods when the rain doesn't provide 2.5 cm of water a week. The more water you provide, the lusher the leaves will be.
The hardy tree mallow will benefit greatly from an annual fertilizing. Feed with a quality, slow-release fertilizer in late winter or early spring. A well-balanced fertilizer, with an N:P:K ratio of 10:10:10, is a good choice. Water generously after fertilizing. Alternatively, a natural organic plant food can be added. You can also mix some organic compost into the soil when planting your tree mallow to enrich it and regulate drainage.
The tree mallow, especially the bushier varieties, benefits from occasional pruning. Trimming should be done in late winter or early spring when the frosts have passed. If freshly pruned plant tissue is exposed to freezing temperatures, it can be damaged by frostbite. Trim the shoots down to the first set of leaves, which will stimulate new and healthy dense growth. Use clean, sharp shears and always disinfect your tools in between the cuts to reduce the chances of possible cross-contamination.
My common tree mallow is turning brown. Why is this happening?
My tree mallow has yellowing leaves and only a few blooms, what can I do?
It sounds like your tree mallow is lacking in sunlight. Remember that the tree mallow needs full sun exposure and at least six hours of it. If possible, move the plant to a more suitable position and mix in some organic compost with the soil, to give it a little boost and help it to regain its vigor.
Pests and Diseases
Pythium root rot manifests itself as discoloration, wilt, and stunting of the leaves. this disease can only be diagnosed by digging up the plant and examining its root system. If present, the roots will be brown and stunted. this is a very serious fungal disease and should be treated immediately when spotted. Remove dead roots and use a sharp, clean tool to trim all remaining affected roots. Cut large portions of the root to ensure that the fungus does not spread. Flush the remaining soil as the fungus mycelium might be still there. Remember to disinfect your tools between the cuts as to not cross-contaminate the healthy roots. If growing in a container, thoroughly wash the pot before using it again.
Rhizoctonia aerial blight symptoms include dark, wet lesions appearing on the leaves of the tree mallow. this is a pathogen that is caused by excess water. Symptoms appear and escalate very quickly; if left untreated, the whole plant may look soggy and could also be covered with the web-like mycelium of the fungus. The best course of action would be to use a fungicide spray. Always apply this outdoors to minimize breathing the chemicals. You can use this to try to kill the pathogen in the soil too, but the safest course of action would be to remove the soil and repot the plant in a new container if possible.
Aphids are tiny insects that gather on the undersides of the foliage, feeding on the sap of the stems and leaves. When feeding, they excrete sticky substances that can attract ants. Aphids can also be vectors of several fungal, bacterial and viral diseases and should not be left untreated. A natural method of control is to introduce ladybugs, which will feed and control the aphids. A fungicide spray, or a soapy water mixture, will also work well.
Sawflies often attack the tree mallow by laying their eggs on the plant in great numbers. When the eggs hatch, the pests start to feed on the leaves, and because of their large numbers, they can often devour the entire plant. The initial symptoms can often be spotted on the underside of the leaves - the larvae will eat everything except the leaf veins. They are best controlled by manual removal in combination with a foliar insecticide.
Other Uncommon Pests or Diseases
Moreover, there are some less common pests and diseases listed below that need your attention:
- Rust Disease
- Leaf Spot
- Gray Mold