Understanding Tree Mallow
Tree mallow (Lavatera arborea) is a large deciduous shrub native to the Mediterranean region, Western Asia and Northern Africa. It can reach up to 3 meters in height and spread 4 meters wide. Tree mallow has large, deep pink flowers and rounded, lobed leaves. It blooms from spring through summer and drops its leaves in fall.
Tree mallow thrives in areas with hot summers and mild winters. It requires full sun and well-drained soil to flourish. Tree mallow is durable and low-maintenance, tolerant of coastal conditions and pollution. It is also resistant to damage from deer and rabbits. Due to its size and sparse foliage, tree mallow works well as a specimen plant or in informal hedges and screens.
The genus name Lavatera honors the Swiss naturalist Lavater, while the species name arborea refers to the shrub’s tree-like size and stature. There are over 25 species in the genus, ranging from annuals to shrubs. L. arborea is one of the largest species, earning the common name “tree mallow”.
Planting Tree Mallow: A Step-by-Step Guide
To plant tree mallow, choose a spot in full sun with fertile, well-drained soil. Tree mallow prefers slightly alkaline soil with a pH between 7 and 8.5. Test your soil to determine the pH and nutrient levels before planting. Apply lime to raise the pH, if needed.
Dig a hole that is at least two times the width of the root ball. The hole should be slightly shallower than the root ball. Do not amend the soil with compost or fertilizer, which can burn the roots.
Space the plants at least 2 to 3 meters (6 to 10 feet) apart. Tree mallow will grow quite large, so give the plants adequate room to spread.
Remove the plant from its container and loosen the root ball. Place the plant in the hole, positioning it at the same depth it was in the container. Backfill the hole and tamp the soil around the base of the plant with your hands to remove air pockets.
Water the tree mallow thoroughly after planting. Provide about 2 to 3 centimeters of water per week during the first growing season while the plant is establishing. Add more water, especially in hot and dry weather.
Apply a layer of mulch around the base of the plant about 5 to 10 centimeters deep. Mulch will help retain moisture in the soil and prevent weeds. Pull weeds regularly, especially during the first few years after planting.
Fertilize tree mallow in early spring before new growth starts and again in midsummer. Use a balanced, all-purpose fertilizer with equal parts nitrogen, phosphorus, and potassium such as 10-10-10. Follow the directions on the product packaging and be careful not to overfertilize.
Prune tree mallow to shape it and improve its structure after flowering is complete. Remove any dead or damaged branches. Pruning will also help facilitate air circulation and sunlight exposure for the inner parts of the plant.
With the proper site conditions and care, a young tree mallow shrub will grow quickly and fill in within a few years to become a delightful garden specimen for years to come.
Tree Mallow Care: Tips and Tricks
Once established, tree mallow is relatively low-maintenance. However, some basic care is required to keep the plant healthy and looking its best.
Water tree mallow regularly, especially for the first few years after planting. Provide about 2.5 to 5 centimeters (1 to 2 inches) of water per week. The soil should dry out slightly between waterings. Mulch around the base of the plant to help retain moisture in the soil.
Fertilize tree mallow in early spring before new growth starts and once during the summer. Use a balanced fertilizer with equal parts nitrogen, phosphorus, and potassium such as 10-10-10. Apply according to the directions on the product packaging. Overfertilizing can burn the foliage.
Prune tree mallow after flowering to shape it and improve its structure and air circulation. Remove dead or damaged branches and any stems that are crossing or rubbing. Pruning will also help maintain the plant’s size and prevent it from becoming ragged.
Mulch around the base of the plant to control weeds, moderate soil temperature, and help retain moisture in the soil. Apply a 2 to 5 cm (1 to 2 inch) layer of mulch, pulling it a few inches away from the trunk. Organic mulches such as shredded bark, wood chips, and pine needles make excellent choices.
Watch for common garden pests such as spider mites, aphids, leafhoppers, and scale, especially during hot, dry weather. You may spot their damage or see the pests themselves on the foliage. Most can be controlled by spraying them off with a strong jet of water or applying insecticidal soap. Reapply as necessary.
Check for disease issues such as powdery mildew, leaf spot, and rust. These fungal pathogens often attack during periods of high heat and humidity. Remove and destroy infected plant parts. Apply neem oil or a fungicide to protect healthy growth. Improve air circulation around the plant.
With minimal maintenance, tree mallow will grace your garden for many years. An occasional pruning, fertilizer application, pest monitoring, and disease management will help keep this Mediterranean beauty thriving.
Tree Mallow Propagation: How to Multiply Your Plants
Tree mallow propagates readily from seed, cuttings, and division. Seeds offer an easy way to raise new plants and maintain the species. Collect seeds in fall once the seed capsules split open. Stratify the seeds by mixing with damp sand and refrigerating for 6 to 8 weeks. Sow in spring and germination will occur in 2 to 4 weeks.
Softwood cuttings taken in late spring provide an effective means of propagation. Choose healthy, vigorous shoots and remove the lower leaves, keeping at least two pairs intact at the top. Dip the cut end in rooting hormone (optional) and stick in well-draining rooting medium such as perlite. Place in a location with bright light but not direct sun. Keep the medium moist and cover with a plastic bag to increase humidity. Roots will form in 2 to 4 weeks.
Semi-hardwood cuttings can also be taken in summer. Follow the same guidelines as for softwood cuttings. Semi-hardwood cuttings may take slightly longer to root but often produce sturdier plants.
Division is best done in late winter or early spring. Use a shovel to slice mature shrubs into halves or quarters, ensuring each division has roots and shoots. Divisions will recover and establish faster than cuttings. Replant the divisions promptly at the same depth in well-amended, properly prepared soil.
Layering is a method of propagation where low-growing branches are stimulated to develop roots with the branch still attached to the parent plant. Bend a low, flexible branch to the ground and slightly wound the area where the roots will form. Bury several nodes under the soil, leaving the tip exposed. Keep the soil damp while rooting takes place. Once roots have developed, sever the new plant from the parent and transplant.
With several simple propagation techniques to choose from, tree mallow can easily be multiplied to produce new plants, whether to expand your own garden or share with others. By propagating from the healthiest plants, you will be rewarded with vigorous offspring for years to come.
Common Pests and Diseases of Tree Mallow
While generally low-maintenance, tree mallow can be susceptible to certain pests and diseases, especially if the plant is stressed. Monitor your tree mallow regularly for signs of damage or disease and treat them promptly to prevent major issues.
Aphids are common sap-sucking insects that attack tree mallow, particularly in spring. Look for clustered, small green or black insects on buds, leaves, and stems. A strong spray of water can dislodge them, or apply insecticidal soap or neem oil.
Spider mites are tiny spider-like pests that spin fine webs on leaves and feed on tree mallow, causing stippling damage. Spray them off with water or apply miticide for heavy infestations.
Caterpillars such as gypsy moth larvae will chew holes in tree mallow leaves. Handpick caterpillars or apply Bacillus thuringiensis (BT), spinosad or neem oil. Cover plants with netting to exclude adult moths.
Powdery mildew appears as white powdery spots on leaves, stems, and flowers. This fungal disease thrives in humid weather. Improve air circulation around plants and apply neem oil, potassium bicarbonate or sulphur fungicide. Water in the morning so leaves dry during the day.
Rust causes yellow-orange spots on leaves and stems. Like powdery mildew, rust needs moisture to spread. Remove infected plant parts and apply a fungicide.
Leaf spots result in dark, dead areas on leaves surrounded by a yellow halo. These fungal leaf spot diseases spread during wet weather. Remove affected leaves and spray plants with copper or sulfur fungicide before the spots spread.
Root rots caused by fungi such as Phytophthora can attack tree mallow, especially in poorly drained soil. The plant will appear stunted and wilted. Improve drainage and aeration around the base of the plant. Remove diseased roots and surrounding soil before planting in a new location with amended, fast-draining soil. Apply a fungicide drench to protect new growth.
Proper site selection, cultivation, and care can help prevent many pest and disease issues on tree mallow. Monitor plants regularly and take prompt action if problems arise to support the long-term health and vitality of your tree mallow.