Lavatera is a genus in the mallows plant family that comprises 25 plant species, both perennials and annuals. Like hibiscus, lavatera have large, showy, funnel-shaped flowers and five separate petals.
Tree mallow (Lavatera maritima) is a semi-evergreen subshrub and a fast grower so it’s a good choice if you want to fill an empty space quickly. With its showy flowers, it is a colorful eye catcher. Butterflies, birds and hummingbirds love it, too. But there’s one caveat: Tree mallow is a short-lived plant with a life span no longer than five years so it will require replanting.
|Botanical Name||Lavatera maritima|
|Common Name||Tree mallow|
|Mature Size||Six to eight feet height, eight to 12 feet width|
|Sun Exposure||Full sun|
|Soil Type||Well-drained sandy and loamy soil|
|Soil pH||Acid, neutral and alkaline|
|Bloom Time||Summer to fall|
|Flower Color||Pale lavender to purple|
|Hardiness Zones||6 to 8|
|Native Area||Western Mediterranean|
How to Grow Lavatera
Once established, lavatera has good drought-resistance and requires little maintenance. The shrub has a mounding but rather irregular growth habit, and it can serve as a screen or as the backdrop in a flower bed.
If you want to give it a neater, more uniform appearance, you can shape it by pruning it.
Being a native of the Mediterranean, lavatera needs plenty of sun.
The plant does well in light, fertile soils, but can withstand poor rocky soil like in its natural habitat. However, excellent drainage is crucial.
Water it regularly until the plant has established a good root system, which takes about one year. After that, switch to occasional watering only in the absence of rain. Because tree mallow does not like wet soil, make sure the soil has fully dried out before watering.
Temperature and Humidity
Tree mallow needs warm and dry weather. While the plant is frost-hardy, it does best in a sunny spot. It should be protected from cold winds.
Only fertilize it once with a slow-release complete fertilizer in the early spring before it starts growing. Over-fertilizing will result in lots of foliage yet few flowers.
Annual pruning is key for prolific flowering. In the spring, after the last frost and before the new growth starts, cut out all the dead, damaged, and woody stems at the base. Only leave the stems where you can see a new shoot developing, or the stem shows a swelling on the stem from which the new shoot will emerge. Cut those stems above the new growth, about one foot above ground level. If you are unsure whether a stem is dead, bend it. If it snaps easily, it’s dead.
Other Lavatera Species
The two other popular lavatera species are:
Tree mallow (Lavatera thuringiaca), a perennial from central and southeastern Europe with a profusion of pink flowers from mid-summer through autumn. Like Lavatera maritima, it is a fast-growing and drought-tolerant woody subshrub.
Growing it follows the same rules as for its Western Mediterranean counterpart.
A popular cultivar is Lavatera ‘Barnsley’ (Lavatera x clementii).
Rose mallow (Lavatera trimestris), on the other hand, is an annual that is propagated from seed. It grows in a mound similar to a shrub so a little confusingly, it’s sometimes also called tree mallow although it only grows two to four feet tall.
Growing Lavatera in Containers
Tree lavatera can be grown as a patio plant in a container but it might have to be cut back more often to control its fast growth. Also, in a container, it needs more frequent watering.
Tree mallow is mostly free of pests and diseases but deer and groundhogs are known for having an appetite for mallows.