The characteristics of Althea
- Type: flowering shrub
- Height: up to 5m
- Flower color: red, white, pink, mauve, blue, bicolour
- Desired exposure:sunny, semi-shaded
- Type of soil: well drained, limestone
- Foliage: obsolete
- Location: living room, dining room, balcony, border, terrace
- Sanitizing: no
Origins and characteristics of Althea
The althea, whose real name is hibiscus syriacus, is a shrub of the Malavaceae family. Originally from Asia, he arrived in Europe in the 16th century. The althea hibiscus plant is easy to grow, it has deciduous, simple, oval and sometimes toothed leaves. The altea flower is ephemeral and has central symmetry. Althea is mainly used for ornamental gardens.
What all the different hibiscus varieties have in common is the presence of twisted flowers before they open. The flowers have an ephemeral lifespan but they renew themselves quickly.
It exists more than 370 species of althea, mainly from temperate Asian countries, such as China or India. The best known species of althea and hibiscus are hibiscus rosa and hibiscus syriacus. The altea flower has two particularities, it can be simple like that of the hamabo variety or be double like that of the Jeanne d'Arc variety. Originally purple, althea flowers have been the subject of numerous hybridizations on the part of gardeners for several decades, and we now find white, pink, red, blue but also two-tone.
Generally cultivated as a pleasure plant, althea is edible and has many cough and angina fighting properties. Althea is also reputed to be an emollient plant, it is used in cosmetology to hydrate atopic or very dry skin.
The althea can be grown either in pots, or in the ground in beds or borders. In pots, it can be planted all year round. To do this, create a mixture of loam, peat and leaf compost. For planting in the open ground, it must be carried out in autumn or spring. Favor a calcareous and well drained soil.
This plant also requires good sun exposure. So be sure to choose the place where you will install your altheas after planting. If you have chosen pot planting, install it in front of a north-facing window.
The althea multiplies in sowing, in spring, between 13 and 18 ° C.
The althea shrub grows from thirty to forty centimeters per year. It is therefore necessary to prune it in winter quite significantly. The althea size varies according to the species, some do not exceed 1.50 m while others can reach 5 m in height. The pruning of the althea is done sporadically: in February / March, we come to remove the stems which are not aesthetic, or those which tend to elongate after flowering.
It flowers on the wood of the year. If your althea is in a pot, you can repot it if necessary and take it outside, placing it in a semi-shaded place.
Althea enjoys exposure to full sun and tolerates low temperatures, down to -15 ° C. However, during frost, it is recommended to protect it with a winter cover. Althea flowers appear from July to November.
Althea (or hibiscus syriacus) must be watered twice a week during the summer period. If the flower buds fall off, your shrub is lacking in water.
Althea diseases and pests
It is especially the indoor altheas that are affected by pests. We must therefore closely monitor the appearance and attacks of aphids, mealybugs, whitefly.
In case of an attack, here are some natural recipes to get rid of pests:
- aphids: spray soapy water (with black soap) on the foliage.
- mealybugs: spray for 3-4 days a solution composed of water, liquid black soap, vegetable oil and alcohol at 90 ° C.
- the white fly: spray water mixed with liquid black soap on the foliage when the colony is well established.
Powdery mildew, caused by a fungus, is one of the most common diseases of althea. To avoid the disease, it is recommended to water your althés rather at the level of the foot and to space the plantations.