How to Grow Marshmallow Plants

Imagine growing marshmallows yummy 😋. The truth is there is a species used to make marshmallow treats made by the Ancient Egyptians using the Althaea officinalis roots, hence the marsh mallow plant.

Today we will look at growing marshmallow plants and harvesting marshmallow roots.

Plant Name: Althaea officinalis

Other Name: Marshmallow or Marsh Mallow

Plant Type: Perennial herb

Native Areas: Asia and Europe

Light Requirement: Full sun

Watering: Moderate


Toxicity: Non-toxic



Growth: 3-6 feet tall and 2-4 feet wide

Soil Type: Acidic, alkaline, and neutral soils

USDA Hardiness Zones: 3-9

More About Marshmallow Plant

beautiful white flowers of marshmallow

When we think 🤔 back to centuries ago when the Egyptians harvested marshmallow roots to make these delicious treats, the sweets we know today contain no plant traces anymore. Today we grow marshmallow plants more for ornamental purposes.

The Marsh Mallow plant belongs to the Malvaceae or mallow family and reaches five feet tall.

It puts up a dramatic display in the garden when it blooms. Pollinators love the plant marshmallow as the tall, elegant spikes are covered with pink-white flowers in spring. In late summer, you see brown seed pods that release tiny black seeds once it stops blooming.

Still, depending on your climate, you can plant these seeds in early fall or spring. This flowering plant with pink flowers used to be used not only as ornamental plants but also for medicinal purposes.

Althaea Officinalis Care

Caring for the marshmallow plant is not difficult and suitable for wet gardens. But as it thrives in moist soil, it also prefers full-sun soil to grow. Hence, do not grow them where taller plants will take all the light. While they grow in moist soil, please provide them with drainage at the same time.

In the late fall, they can be directly seeded in the ground with mild winters.

If the winter is frosty, we recommend sowing marshmallow seeds in early spring. Sow the seeds about 18 to 24 inches apart per the seed packet. Then add a thin layer of mulch to retain moisture and keep weeds away.

Keep the weed-free area until your plants reach a mature height to help them fend for themselves.

Lighting Needs and Recommended Soil Marsh Mallow Plant

marshmallow under full sun

The most important thing with the marshmallow for the flower buds to develop is full sun, as it does not do well in the shade. True to Marsh Mallow, it thrives in wetland areas in damp soil standing in full sun. It also enjoys rich soil that is slightly acidic and can grow in a sandy loam environment.

Add some sand with compost to make it full of nutrients, and add some coffee grounds. Still, the marshmallow plant can thrive in different soil pH levels, so do not fuss too much.

Watering the Mallow Family

For marshmallow plants, water 💦 is essential as they grow in wet areas in western Asia and North Africa. But also be aware of standing water and best to provide good drainage allowing the excess water to flow away from the marshmallow root.

To amend the soil, you can add some organic matter, and if you see your plant returning yearly, you know the soil is suitable.

Temperature and Humidity

temperature and humidity of marshmallow

When grown in the garden, these tough plants thrive in different climates to humidity levels. The marshmallow plant is cold tolerant but can die back in sub-freezing temperatures. Still, they emerge again in spring.

Fertilizing Plant Marshmallow

balanced fertilizer for marsmallow

As the marshmallow plant grows in different soils, even salty soil, no special fertilizer is needed if you have organic matter present. But you can use a balanced fertilizer in the growing season if no compost is added.

Potting and Pruning Marshmallow Plants

You need not prune the marshmallow plants, but you can deadhead the spent flowers and remove dead leaves to prevent pests and diseases. Grow marshmallows in containers is not recommended as the soil needs to remain moist, and it can dry out faster in pots.

Overwintering Marshmallow Plant

As the species is cold tolerant, it will die back in winter and needs no special protection in the garden. But you can cut away the dead branches and leaves to keep things tidy and increase airflow. It will take several weeks for them to re-emerge in the growing period.

Harvesting Marshmallow Root For Propagation

You can grow marshmallow from root division as follow:

  • Wait until fall for the plant to go dormant, and then in early winter, before the ground freezes, you can divide the roots.

  • Dig up the marshmallow plant with the entire root system.

  • Then divide the root mass into sections using a sharp spade.

  • Replant the sections into a new location and mark them.

You can also do this in early spring before young leaves sprout, but finding them before they sprout is not always easy as they die back in winter.

How to Grow Marsh Mallow Plants From Seeds

You can also plant marshmallow seeds and buy them at a nursery or online. Still, the seed needs cold stratification before you can plant them. You can do this by placing the seeds in the fridge for a few weeks in the package or a plastic bag in moist peat moss.

After the cold period, you can start the seeds indoors about four weeks before the last frost date or sow them in the garden after the frost passes. Direct seed them in groups of six spaced up to 24 inches apart, cover them lightly, and keep them moist.

Common Pests and Plant Diseases

While most parts of the Marsh Mallow are edible, pests leave it alone. One bug 🐛 that can become a problem is flea beetles, brown-black-gray insects laying eggs near the root. The larvae feed on the leaves, making holes. You can apply some neem oil to deter them.

The Marsh Mallow can get rust presented with white dots on the underside of foliage, turning orange to yellowish-green and black. You can remove the diseased leaves, prevent overhead watering, and use a copper-based fungicide.

Frequently Asked Questions

The primary problem is the lack of water which causes them to die. So, grow marshmallow seeds in an area with natural moisture or water them often to prevent them from drying out.

If your marshmallow species do not bloom, it is a lack of sun. You can move them to another location to receive direct sunlight and prune away surrounding plants casting shade.

Sometimes the plant becomes confused with the common mallow Malva sylvestris and the tree mallow Lavatera. The Marsh Mallow plant has multiple stems with fuzz down the stem with blush-colored flowers. The flowers are smaller and paler, with an abundance of blooms compared to mallow. In contrast, Lavatera has bright cotton candy pink blooms with spiky leaves.

You can harvest the root in late fall after they go dormant. You can remove the roots needed and then replant the crown to continue growing. But do not harvest roots from younger species than two years old. People used to harvest the root for herbal medicine to treat coughs, skin irritation, and digestive problems, such as ulcers.

The species reseed but are not considered invasive, and you may see them growing along a marshy roadside or meadow.

The marshmallow cultivar can grow in groups 24 inches apart, and cover the seeds lightly with the growing medium. These species will die back to the ground during winter but return in the growing season.

Whether you want to buy, sell, or simply reach out to other plant enthusiasts, Plantly is the right place to be!

Leave a Reply

Your email address will not be published. Required fields are marked *

Plantly Menu