How to Grow Althea Bush - Plant Care & Tips

By NorwichGardener Team   /   2025

Althea bush is a plant that is native to eastern Asia and has been introduced to North America, where it is now considered an invasive species. It grows in moist areas and can reach a height of up to six feet. The althea bush has dark green leaves and white or pink flowers.

How to Grow Althea Bush - Plant Care & Tips

Also called

  • Marshmallow
  • Mallow
  • Tree Mallow
  • Hibiscus
  • Rose of Sharon

Things to Know

  • Althea bush is a member of the plant family Malvaceae.
  • It is native to North America, where it is found in the eastern and midwestern United States as well as southeastern Canada.
  • The althea bush is a deciduous shrub that typically grows to a height of 3-6 feet.
  • It has ovate to heart-shaped leaves that are 2-6 inches long and 1-3 inches wide.
  • The leaves are green to purple in color and have toothed margins.
  • The althea bush produces white, pink, or purple flowers that are 2-3 inches in diameter.
  • The flowers are borne in clusters of 3-5 and bloom from June to September.
  • The althea bush is pollinated by bees and other insects.
  • The fruits of the althea bush are dark brown, spherical, and have a diameter of 1/2-1 inch.
  • The althea bush is often used as an ornamental plant in gardens and landscapes.

Related plant:
Althea Flower

How to Grow

  1. For althea bush, first step is to purchase a plant that is already started.
  2. Second step is to plant your althea bush in a hole that is twice as wide as the plant’s root system and just as deep.
  3. After planting, water your althea bush deeply to help settle the roots into their new home.
  4. Once the plant is established, water it on a weekly basis, making sure to deeply water the root system.
  5. Althea bush should be fertilized three times a year – once in spring, once in summer, and once in fall – using a general purpose fertilizer.
  6. To keep your althea bush looking its best, prune it annually in late winter or early spring.
  7. Althea bush is generally a low-maintenance plant, but it may be susceptible to pests and diseases such as aphids, Japanese beetles, and powdery mildew. If you notice any problems, treat them immediately.
  8. Althea bush can be propagated by rooting stem cuttings in late spring or early summer.
  9. If you live in an area where winters are harsh, you may need to provide some protection for your althea bush, such as wrapping it in burlap or putting it in a sheltered location.
  10. With proper care, your althea bush should thrive and provide you with beautiful blooms for many years to come.

Related plant:
Althea Rose Of Sharon

The Soil

About soil , Althea Bush would say that it is the foundation for a healthy garden. She would also say that it is important to check the condition of your soil before planting. Loose, well-aerated soil is ideal for most plants. If your soil is dense and compacted, it might need to be amended with organic matter to help improve drainage.

About light

Just like other plants, Althea bushes need sun to grow and prosper. They should be planted in an area that gets full sun for at least six hours each day. If you live in a hot climate, you may need to provide some afternoon shade to prevent the leaves from burning.

The Temperature

The temperature condition of the area is moderate with an average temperature of 65 degrees Fahrenheit. The area is located in a rural area and is not prone to extreme weather conditions. However, the area can experience occasional high temperatures during the summer months.

Humidity Aspect

Ideal humidity condition for this plant is 50-60%. This plant grows in hot, humid weather and does not tolerate cold weather. Plants grown in too much humidity will have problems with powdery mildew and other diseases.

Fertilizer Requirement

Mentioning fertilizer, this type of plant food is necessary for the growth and development of healthy roots in your plants. Fertilizer encourages root growth by providing the essential nutrients that they need to thrive. Without roots, your plant would be unable to absorb water and nutrients from the soil, so it’s important to give them the care they need! If you’re looking to give your plants a boost, consider adding a root stimulator to your fertilizer routine. Root stimulators help to encourage new root growth and can be especially helpful if your plant is struggling. They’re typically easy to use and can make a big difference in the health of your plants!

Plant Pruning

Pruning is a horticultural practice that involves the selective removal of certain parts of a plant, such as branches, buds, or roots. Pruning often takes place in order to improve the plant's appearance or to encourage fruiting or flowering. It can also be done to remove diseased or damaged parts of the plant. Proper pruning technique is important in order to avoid harming the plant.

About Propagating

Propagation is the process of creating new plants from existing ones. Althea bushes can be propagated from seed, cuttings, or root division. Seed propagation is the most common method, but it can take several years for the bush to flower. Cuttings can be taken from new growth in late spring or early summer. Root division is best done in early spring.

Growth Rate

Usually, the plant growth rate is determined by the type of plant. Many althea bushes can grow up to three feet per year, while some only grow one foot per year. The size of the bush also determines the althea bush growth rate. A bush that is six feet tall will typically grow at a slower rate than a bush that is three feet tall.

The Problems

Common problems for this kind of plant are root and stem rot, blight, aphids, and spider mites. Root and stem rot can be caused by overwatering or by planting in poorly drained soil. Blight can be caused by several different fungi, and is characterized by brown or black spots on the leaves. Aphids are small, soft-bodied insects that suck the sap from plants, and can cause distorted growth. Spider mites are tiny spider-like creatures that feed on the undersides of leaves, and can cause the leaves to turn yellow or brown.

Growing Tips

  • If you are growing althea bush in pots, make sure they are at least 18 inches deep.
  • Althea bush needs full sun to partial shade.
  • Althea bush prefers well-drained soil.
  • Water althea bush regularly, but do not over-water.
  • Fertilize althea bush every two weeks during the growing season.
  • Deadhead althea bush regularly to encourage new growth.
  • Althea bush can be pruned in the late winter or early spring.
  • Althea bush is susceptible to powdery mildew, so avoid overhead watering.
  • Althea bush is also susceptible to root rot, so make sure the soil is well-drained.
  • Althea bush is a fast-growing plant, so be prepared to stake it if necessary.

You May Like

  • Alders (Alnus rubra)
  • Ash (Fraxinus americana)
  • Alum root (Heuchera americana)
  • Alder buckthorn (Frangula alnus)
  • Azalea (Rhododendron species)
  • Aralia (Aralia spinosa)
  • Andromeda (Pieris japonica)
  • Aeonium (Aeonium arboreum)
  • Albumen plant (Ambrosia trifida)
  • Amur Cork Tree (Phellodendron amurense)

Source:
Common Name: Scientific Name: Hibiscus syriacus - Louisiana …
Blakeney Garden: Annual garden (Althea bush) | Gardens
Staff Directory/Contact Info • The Bush School of Government

Richelle Author Photo
Reviewed & Published by Richelle
Submitted by our contributor
Shrubs Category