Althaea

( AL - thee - uh )

At-A-Glance Information

This genus of herbaceous perennials hails from Europe, North Africa, and western Asia, and includes the plant that is known for giving rise to the sugary confection known as Marshmallow. Flowers typically range in color from white to pink to light purple, and resemble those of Hibiscus. These are beautiful landscaping plants that can be used in mixed borders and beds, or harvested for their roots.

Althaea Species and Varietals

The genus Althaea is a member of the plant family Malvaceae, and includes 9 species. Althaea plants can be grown in any zone; To find your zone, click here: Zone Map.

Althaea armeniaca (Russian Mallow, Armenian Marshmallow)
This species forms a tall, erect perennial herbaceous plant with deeply lobed leaves with serrated margins. Flowers are reddish pink. These plants are native to Russia, central Asia, Turkey, northern Iran, the Transcaucasus, Lebanon, and Syria. Individual plants reach up to 6-8 feet tall and 1.5 to 3 feet wide at maturity.

Althaea cannabina (Hemp-Leaved Hollyhock, Palm-Leaf Marshmallow)
This species is native to central and southern Europe as well as the Mediterranean basin. Plants naturally grow in thickets, coastal areas, forests, meadows, and a wide variety of other sites. At maturity, this species can reach up to 79 inches tall, forms erect stems, and has leaves that resemble those of Cannabis sativa plants (hence the specific epithet, cannabina).

Althaea officinalis (Marsh Mallow, Marshmallow)
This species is native to Europe, Western Asia, and North Africa. Its roots are used to create a sweet confection that evolved over time into today's Marshmallows (though they no longer contain any roots). Plants reach up to 6 feet tall and put out few lateral branches. Flowers are pinkish to white and bloom in August through September.

Caring for Althaea

Althaea plants, due to their deep tap root, are not commonly sold in nurseries; it is more common to grow these plants from seed. These hardy perennial plants should be planted in full sun; they will leaf out and bloom better when they receive at least 6-8 hours of sun each day. They prefer soil to be moist and well-draining, with a slightly acidic pH (between 6.0 and 7.0). If local soils are particularly poor, make sure to amend the planting site with plenty of organic material and compost before installing plants. Apply a layer of mulch around the planting area to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water new plantings regularly as they establish a strong root system in their new home. At maturity, these plants appreciate consistently moist soils, but not waterlogged conditions. As a general rule of thumb, water whenever the top inch of soil feels dry to the touch.

Fertilize yearly in early springtime with an application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. These plants are not heavy feeders, and this should be sufficient to provide the necessary nutrients for the active growing and flowering seasons. After plants flower and blooms begin to fade, cut off flowering stems and tattered growth. In late winter or early springtime, cut back the whole plant to the ground for a rejuvenation. It will fully recover and bloom again in the same season. Althaea plants can be perennials or biennials, typically living for a few years in the landscape before needing to be replaced.

Harvesting Althaea Plants
Many parts of these plants can be used in a culinary setting. They were a commonly consumed vegetable that was considered a delicacy among the Romans, and when roots are boiled and then fried with onions and butter, it forms a palatable dish. Young leaves can also be cooked, and flower buds can be pickled. Water used to boil any parts of the plant can be used as a substitute for egg whites. Leaves and flowers can be harvested at any time of the year; in springtime is best, as they will be at their peak of flavor and growth. To harvest the taproot, the entire plant needs to be dug up carefully in fall of its second year in the ground, and the tap root removed. Rinse the taproot, cut it into small pieces, and then lay the pieces out to dry in a well-ventilated, cool, dark area. They can also be laid on a baking sheet and baked at low temperature until they are completely dry and brittle. Store dried roots in an airtight container in a dark, cool space.

Disclaimer: Information contained on this website is strictly and categorically intended as a reference to be used in conjunction with experts in your area. Foraging and consumption of plant parts should never begin without the guidance and approval of a local plant specialist. The providers of this website accept no liability for the use or misuse of information contained in this website.

Propagation

These plants, due to their deep taproots, are best propagated by seed. They do not like to be moved after they have been established, and are not typically sold in nurseries as starts. To propagate your Althaea plant, follow the instructions below:

Propagating Althaea by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand. You will also, after a few weeks, need individual 3-inch pots for each seedling that grows.
Harvest your seeds. The seed pods are left behind after flowers have faded, and contain tiny brown to blackish seeds in late fall. Seeds will begin to fall from their attachments when they are mature. Collect as many as you can, as they may not all germinate, and the ones that do may have varying characteristics.
Althaea seeds will need a period of cold-stratification before they will germinate. To complete this process, place harvested seeds in a bag or other sealable container filled with moistened peat moss or sand, and place the container in the refrigerator. Leave it there for between 3 and 6 weeks' time. Then, remove the bag and bring out the seeds so they can be sown.
Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 7-14 days from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.