Mallow: flowering time, cultivation & care

Regina
Regina
Regina
Regina

I studied horticultural sciences at university and in my free time you can find me in my own patch of land, growing anything with roots. I am particularly passionate about self-sufficiency and seasonal food.

Favourite fruit: quince, cornelian cherry and blueberries
Favourite vegetables: peas, tomatoes and garlic

The mallow is an attractive flowering perennial that is ideal for the garden and, given the right location, is also easy to care for. Keep reading for tips on how to grow mallows and how to help them thrive in your garden.

Mallow flowers in partial shade
Mallows are undemanding plants with a long flowering period

Mallows (Malva) are admired for their long-lasting flowers, abundant varieties and their many uses in the garden and in the kitchen. Read on to learn all about how to plant, care for and use mallows.

Mallow: flowers, leaves and origin

Mallows, also sometimes called cheeses or high mallows, belong to the mallow family known as Malvaceae. They are closely related to hibiscus (Hibiscus), okra (Abelmoschus esculentus) and marsh mallow (Althaea officinalis). The genus Malva currently contains around 150 species that can be found across the globe in temperate and subtropical climate zones. All Malva species have edible roots, leaves, flowers and seeds and a high mucilage content, which is helpful in providing relief from irritating coughs.

Mallows grow between 10 and 200cm tall depending on the species. Most mallows grow upright and form simple or branched green stems, some with a red tint. Biennial species form a rosette of leaves in the first year and flower the following summer. The hairless or lightly hairy alternate Malva leaves are lobed and oval or round, and they each grow from a stalk. Mallow flowers also grow from stalks which emerge from the leaf axils individually or in groups of up to four. Each flower has five petals that are broadly triangular. Their colours can range from white to pink to purple and many have deeper shades toward the centre of the flower. After pollination, mallows form flat, disc-shaped seed capsules, which then break into several parts when mature, releasing the mallow’s seeds.

A single mauve mallow flower
Mallow flowers each have five individual petals

Are mallows perennial?

There are both annual and perennial members of the Malva genus. Many species of mallow are short-lived, but they seed abundantly, providing plenty of seeds for replanting. For other species, such as the musk mallow (Malva moschata), the plant’s lifespan can be extended by pruning immediately after the plant flowers. Read all about the most common mallows for gardens and some of their close relatives in our article on different species and varieties of mallow.

When do mallows flower?

The flowering time for mallows stretches from May to October, making it an important plant for pollinators, especially in late summer. In fact, because mallows are so bee-friendly, they are often included in flower mixtures. Bumblebees especially enjoy the easily accessible Malva flowers as a food source, as they offer plenty of nectar and some pollen.

Bee on a mallow flower
Bees and bumblebees find plenty of nectar in mallow flowers [Photo: HWall/ Shutterstock.com]

Planting mallows

Mallow plants are typically started from seeds, but planting mallow seedlings is also possible. In the garden bed, mallows harmonise wonderfully with plants from the mint family (Lamiaceae) such as motherwort (Leonurus cardiaca), obedient plant (Physostegia virginiana) and hyssop (Hyssopus officinalis). They are also great companion plants for scabiosa (Scabiosa), mullein (Verbascum) and feverfew (Tanacetum parthenium) which, when planted together, create a beautiful, colourful flowering meadow.

When to plant mallows

The ideal time for planting mallows varies depending on the species, growth habit and lifespan. Sow annual mallows directly into the bed in spring; plant out seedlings from May onwards. Keep a planting distance of 20 to 30cm for annuals, as they do not grow very wide. Sow perennial mallows in spring, but plant out young plants either in autumn or spring. The planting distance for perennial mallows is 50 to 70cm. Mallows provide a colourful accent in small groups of three along borders.

Mallow plant in a pot
Mallows can also be grown in pots on the balcony or patio [Photo: guentermanaus/ Shutterstock.com]

Location requirements

Malva plants love warm, sunny to semi-shady locations. They thrive in full sun and well-drained, nutrient-rich, not-too-heavy soil. Whilst they will also grow in most other places, their growth or flowering may be stunted. Mallows do not tolerate waterlogging, so compacted and wet locations are not suitable. If planting your mallow in a pot, check to make sure the pot has drainage holes, create a drainage layer at the bottom of the container and use a well-drained soil. You can also plant Malvae in a planter or balcony box. We recommend using a nutrient-rich potting soil with good water retention, such as our Plantura Organic Flower Compost. Our peat-free soil is also enriched with crushed expanded clay, which loosens the soil structure, allowing the mallow’s roots to get enough oxygen. When choosing a planter for mallows, opt for one that holds at least 10 litres of soil.

Organic Flower Compost, 40L
Organic Flower Compost, 40L
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(5/5)
  • Perfect for all flowering plants in garden beds & pots
  • For beautiful blossoms & healthy plant growth
  • Peat-free & organic soil: CO2-saving composition
£16.99

Sowing mallow seeds

From March to May, mallow seeds can be sown directly outdoors. They do not need to be started indoors beforehand. In fact, many mallows do not tolerate being transplanted and may not grow or flower as well as those sown directly outdoors.

Before sowing, prepare the chosen spot by removing any weeds, wild herbs or large stones. Prepare the soil to a fine-crumb consistency. Cover the seeds lightly with 0.5 to 1cm of soil — this goes for seeds sown in planters as well. If you want to sow over a larger area, such as for bee pastures, spread the seeds over the chosen area, and lightly rake them into the soil. Keep the soil moist; do not allow it to dry out. With soil temperatures above 15 °C, the seeds will germinate after 1 to 2 weeks.

A mallow seedling in soil
In the right conditions, mallow seeds only take a few days to germinate [Photo: Manfred Ruckszio/ Shutterstock.com]

Plant care

Mallows are low-maintenance plants with a long flowering period and healthy growth, making them a great option for beginners. However, the following care points are crucial:

Watering and fertilising

The most important mallow care measure is watering. This is especially important for germination, after planting seedlings and during hot dry periods. If your mallow has yellow leaves, it may very well be thirsty.

Perennial mallows enjoy a helping of fertiliser in spring to support growth and flowering. Use a slow-release fertiliser such as our Plantura Flower Food. Simply spread the low-dust granular fertiliser around the base of the plant and work it into the soil’s surface before watering. The organisms in the soil release the nutrients from the fertiliser over several weeks, providing the mallow plants with a consistent supply of nitrogen and other essential nutrients.

Flower Food, 1.5kg
Flower Food, 1.5kg
  • Perfect for flowering plants in the garden & on the balcony
  • For healthier plants with beautiful & long-lasting blossoms
  • Long-lasting fertiliser that is free from animal products - child & pet friendly
£12.99

Pruning mallows

Only perennial mallows need pruning, because the above-ground foliage dies. We suggest pruning directly after flowering, as this boosts the plant’s longevity and winter hardiness. It also prevents unwanted reseeding. When annual mallows die off in autumn, remove them from the bed entirely or use them as mulch. Remember that annual mallows are also prolific at self-sowing.

Common diseases and pests

There are a few diseases and pests that are drawn to mallow plants. Common mallow pests include aphids (Aphidoidea) and spider mites (Tetranychidae). However, these rarely cause much damage. Although mallows are robust plants, one disease that is common is mallow rust (Puccinia malvacearum). Mallow rust causes orange-brown pustules to form on the leaves and stems. This disease mostly affects plants that are suffering as a result of being in unfavourable locations or are enduring long dry periods or prolonged periods of rain. In other words, mallow plants that are stressed are more susceptible to it. Remove all affected plant parts immediately and dispose of the cuttings in the household waste to prevent the pathogen from spreading further.

Leaves damaged by mallow rust
Mallow rust mainly attacks the leaves and stems [Photo: matunka/ Shutterstock.com]

Propagation

Both annual and perennial mallows can be propagated by seed. To harvest mallow seeds, allow the seed heads to mature until they turn brown; this is usually between August and October. When the seeds are ready for harvest, cut off the seeds stalks and lay them out to dry at room temperature. When they are dry enough, the seed heads easily break into individual seeds. Once this happens, store the seeds in a cool, dry and dark place. Mallow seeds remain germinable for many years.

Dried mallow seeds
Mallow seeds can be harvested in late summer or autumn [Photo: KarinR/ Shutterstock.com]

Perennial mallows can also be propagated and rejuvenated by dividing. When the mallow is large enough, locate a section with roots, and use a sharp spade to cut it off. Then, simply plant the removed section in a suitable location. In theory, mallows can also be propagated using cuttings, but this is more time-consuming and less promising than propagating by seed or division.

Are mallows hardy?

Whether a mallow is hardy depends on its species. In general, perennial mallow species are frost-tolerant down to -25 °C. The foliage of perennial mallows dies off in late autumn and serves as additional frost protection. Even biennial mallows that overwinter as leaf rosettes can survive our sub-zero temperatures and usually do not need any additional protection. However, mallows in pots need protection in harsh conditions, as the soil in pots is more likely to freeze through, which would damage the plant’s roots. To overwinter potted mallows, place the planter in a sheltered position, for example against a house wall, and insulate the pot with jute or fleece. In the case of a winter drought, give your potted mallow a little water on frost-free days; otherwise potted mallows do not need any care in winter.

Mallow leaves covered with frost
Most species of mallow are hardy in the UK [Photo: gianpihada/ Shutterstock.com]

Are mallows poisonous?

All parts of a mallow plant are edible for humans and animals. In fact, numerous species are used in cooking and herbal medicine to alleviate illnesses.

Uses and medicinal benefits

All parts of a mallow plant are edible and can be used in the kitchen. In the past, the unripe, green seed pods were used to cook nutritious porridge for children. Ripe seeds can also be roasted in a pan and salted to make a snack. The leaves are a healthy wild vegetable and can be used like spinach to refine salads and other dishes. The best species for use as an annual vegetable is Chinese mallow (Malva verticillata), which produces many large leaves and is commonly used in East Asian cuisine. Dried mallow flowers are also popular in teas, because they release their blue-violet colouring into the water.

Dried mallow flowers in water
The flower petals turn mallow tea blue

In herbal medicine, the mucilage from mallow leaves and flowers is used to make tea and cold water extracts. These are then used to relieve dry coughs, sore throats, pharyngitis and other mucous membrane inflammations. Therefore, mallow tea is useful in fighting flu-like infections, colds and upset stomachs.

Another mallow plant is the hollyhock (Alcea), which is popular for its wide variety of flower colours. Learn about these tall bee-friendly perennials in our overview article, and get tips on planting and care.