Marsh mallow

Marsh mallow: how do you recognise it?

Habit

Upright clump 1–1.5 m tall and 50–60 cm wide, with sturdy, hairy stems.

Leaves

Oval to three- or five-lobed, 5–10 cm, toothed and velvety on both sides; grey-green.

Flower

Pale pink to almost white, saucer-shaped flowers 3–4 cm across with five petals, in clusters in the leaf axils, from July to September.

Fruit

A flat, round ‘cheese’ that splits into segments, as in common mallow.

Root

Thick, fleshy and branched, white and slimy inside; it goes deep into the soil.

Flowering: July–September · Harvest and fruit: May–November · Sowing: March–May · Plants: April–May and September · Pruning: March

Why grow it?

• A tall, soft, silvery presence at the back of a border or at the edge of a pond.
• Long flowering from July to September, a food source for bees, bumblebees and butterflies.
• A native plant that suits a natural garden on moist soil.
• Edible young leaves and flowers, and a root with a rich history.
• Tough and very hardy, and it copes with salty sea winds too.

Marsh mallow: where does it grow best?

• Full sun; in partial shade it flowers less and the stems flop sooner.
• Sand, loam or clay, acid to chalky, preferably fertile and rich in humus.
• Moderately moist to wet: ideal at a pond edge or in a moist border; it also tolerates some salty water.
• Plant 50–60 cm apart, at the back of the border or in a group of three.

Light

Sun

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Normal or wet

Size

1.5 m tall, 0.6 m wide

Hardiness

Hardy (to -30 °C)

Goes well with

• Purple loosestrife: Purple-pink spikes in the same damp spot, also native and full of butterflies.
• Meadowsweet: Creamy, scented plumes beside the soft pink flowers at the pond edge.
• Hemp agrimony: A native butterfly plant that flowers at the same time, on wet to moist soil.
• Yellow flag: Sword-shaped leaves and yellow flowers in spring, in the wet margin close to the water.

Marsh mallow: when and how to plant it?

Plant in April–May and September.

1. Plant in April–May or in September, when the soil is not too wet and not frozen.
2. Dig a deep hole, as the root goes deep, and mix in some compost.
3. Set the plant at the same depth as it was in the pot and firm the soil well.
4. Water generously straight away and keep the soil moist for the first few weeks.
5. Spread a layer of compost or leaf mould round the base to stop it drying out.
6. Choose the right spot from the start: because of its deep root it is hard to move later.

Care

Water

Keep the soil moist, especially in dry summers; on a damp site watering is rarely needed.

Feeding

A spadeful of compost round the base in spring is enough.

Support

On a windy site, a few canes or a plant support in May, before the stems grow tall.

Harvesting

Pick young leaves in spring and flowers in summer, for salads or as a garnish. Roots are harvested in October–November from plants at least two years old.

Stems in winter

Leave them standing: insects overwinter in the hollow stems, and the seeds feed birds.

Tip: Give it a moist, sunny spot, for example by a pond, and put a support in place in May: the tall, soft stems will then stay upright all summer.

Marsh mallow: when to prune it?

Pruning months: March.

When: Cut the old stems back to just above the ground in March, before the new shoots appear.

How:

• Leave the spent stems standing over winter for insects and birds.
• In March, cut them back to 5–10 cm above the ground.
• In summer, remove leaves with rust and put them in the household waste.
• If you want fewer seedlings, cut off some of the spent stems in September.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

Sow indoors in March or outdoors in April–May, barely covered. The seed often germinates slowly and unevenly; a few weeks of cold before sowing helps.

Division

In spring or September, lift an old clump and split it with a spade into pieces with roots and buds.

Marsh mallow: how does it get through the winter?

Hardy to −30 °C.

• Very hardy, to about −30 °C: in Belgium no protection is needed.
• The top growth dies back in autumn and the plant shoots again from the root in April.
• Leave the dry stems as winter shelter for insects and cut them only in March.

Diseases and pests

• Mallow rust: Orange-brown pustules on the undersides of the leaves, yellow spots on top. Cut off affected leaves, space the plants and water at the base.
• Slugs: Young shoots eaten in spring. Protect the young shoots and collect slugs in the evening.
• Flopping: Tall stems fall over after wind or rain. Put a support in place in good time and avoid too much fertiliser.
• Aphids: On the tips of young shoots in May–June. Ladybirds usually clear them up; otherwise hose them off with water.

Through the year

• March: Cut back old stems. Sow indoors. Give compost.
• April: Sow outdoors. Plant. Divide old clumps.
• May: Sow outdoors. Plant. Put in supports.
• June: Harvest young leaves. Watch for aphids and rust.
• July: Flowering; bees and butterflies. Pick flowers.
• August: Flowering. Water in dry spells.
• September: Last flowers. Plant or divide.
• October: Harvest roots from plants at least two years old.
• November: Harvest roots. Leave stems standing for winter.
• December: Rest. Dry stems shelter insects.

Edible and useful

Flowers (July–September)

Pick the pale pink, saucer-shaped flowers from July to September, on a dry day. They taste mild and fresh and look lovely in a salad, on a dessert or in a herbal tea.

Leaves (May–July)

Pick the young, velvety leaves from May to July, from the tops of the stems. They taste soft and green and are slightly mucilaginous, like okra (a relative): cut them into strips for a salad, or cook them in soup or a stew, which they thicken a little. Older leaves become tough and woolly.

Roots (October–November)

Dig up the roots in October and November, from plants at least two years old: take part of the roots and replant the rest of the clump. The thick white root is full of mucilage. A cold infusion of it has long been drunk for a dry throat, and the first marshmallows were made with it.

Storing

Wash the roots, scrape the thick ones and cut them into small pieces while still fresh: once dried, they are too hard to cut. Dry them somewhere airy and warm or in the oven at 40 °C with the door ajar until completely dry and hard, and keep them in a closed jar for up to a year. Dry the leaves and flowers in a thin layer on a rack; fresh young leaves keep for a few days in a bag in the fridge.

Caution: The flowers, leaves and root of marsh mallow are edible. The mucilage can slow down the absorption of medicines: do not take them at the same time as marsh mallow, but leave at least an hour in between. A marsh mallow infusion is not a medicine: if symptoms persist, see a doctor. Never dig up roots in the wild: the plant is rare in Belgium. Harvest only from your own garden.

Eating and using is at your own risk: see the terms of use.

Recipes

• Cold marsh mallow root infusion (Tea · 1 cup · 5 min + 1 to 2 hrs steeping)
• Summer salad with marsh mallow and goat’s cheese (Dish · 4 people · 15 min)

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Butterflies

Nectar for butterflies.

Did you know?

• The first marshmallows were made with the mucilage from the root; today’s sweets usually contain no marsh mallow at all.
• In French both the plant and the sweet are called guimauve, and in English marshmallow.
• It is related to the hollyhock, which used to be placed in the same genus as Althaea rosea.