Milkweed is not just milkweed: there are around 200 different species and numerous varieties, all of which have very different requirements in terms of location and care - especially since only a few species are hardy in our latitudes. As a rule, a bucket culture takes place so that you can enjoy the magnificent plants for a long time. When buying, make sure you use the correct species name in order to be able to supply them correctly.

There are over 200 different species of milkweed

Table of Contents

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  1. origin and distribution
  2. appearance and growth
  3. leaves
  4. flowers and flowering time
  5. fruit
  6. toxicity
  7. Which location is suitable?
  8. substrate
  9. plants and repotting
  10. watering and fertilizing
  11. Prune milkweed properly
  12. Propagating milkweed
  13. hibernate
  14. diseases and pests
  15. species and varieties

    16. origin and distribution

    The genus of milkweed includes around 200 different species, most of which are native to the New World - i.e. North and South America. Some varieties are also found in southern Africa between Tanzania / Zimbabwe and South Africa. Some species - such as the common milkweed - now grow as neophytes in many other areas of the world. The genus is assigned to the dogbane family (bot. Apocynaceae).

    appearance and growth

    Most milkweed are perennial, herbaceous plants. Only a few species are only annuals. Depending on the species, Asclepias plants reach heights of between 70 centimeters and two meters. The strong rhizomes from which the plants form numerous offshoots are also typical. Planted out in the garden, they quickly overgrow larger areas, which is why you should definitely install a root barrier when planting.

    leaves

    Visually, the leaves, which have a maximum of short stalks but are up to 17 centimeters long, are somewhat reminiscent of rubber tree leaves. They are typically elliptical to oblong in shape and downy hairy in most species.

    flowers and flowering time

    The usually multi-flowered umbels appear between June and August and shine in bright colors such as pink or orange. Pollination is by insects, especially bees and butterflies, especially since milkweed is valuable pasture for bees and butterflies.

    fruit

    Two spindle-shaped follicles develop per fertilized flower, which usually stand together like two horns. These are densely packed with numerous flat seeds, which in turn are covered with silky hairs up to four centimeters long. The hairiness, called coma by botanists, is used to spread the seeds by wind, and the milkweed owes its species name to it.

    toxicity

    Like all dogbane plants, milkweed is poisonous to both humans and animals. The escaping milky juice can also cause skin irritation.

    Which location is suitable?

    Milkweed prefers to be in full sun, although some species also feel comfortable in light partial shade. Specimens cultivated in pots are best placed outdoors over the summer, but you should slowly get used to the stronger sun intensity. The large space requirement is also important: since the perennials can grow quite tall and also multiply diligently via underground root runners, you should plan a planting distance of at least 50 centimeters when planting beds. Container plants need a correspondingly wide pot.

    substrate

    Milkweed planted in the garden do well in humus rich, well-drained, low-clay soil. The perennials will grow better if you mix some compost under the excavation when planting. A humus-based potted plant substrate is suitable for potted plants, which you can make more permeable with perlite (€37.51) or expanded clay (€19.73). A good pot drainage must not be missing to avoid waterlogging. For this, the planter needs a drainage hole on the bottom of the pot, and you also fill in a drainage layer made of coarse, inorganic material such as gravel or broken pottery as the bottom layer.

    plants and repotting

    Milkweed species that are not or only partially hardy should only be cultivated in containers if possible. In this way, overwintering is no longer a problem - unless you only want to care for the plants once a year anyway. Repot tub specimens into a larger container and/or fresh substrate about every two to three years.

    Only hardy varieties or specimens should be planted out in the garden, which you dig up before the first frost and then overwinter frost-free. The hardy silk plants in particular need a lot of space in the garden, but a root barrier can be used to prevent uncontrolled growth.

    To help the plants root more easily, place them in a bucket of fresh water with the bare root ball before planting/potting. As soon as no more air bubbles rise, the plant is ready for planting.

    watering and fertilizing

    For healthy growth, silk plants depend on an adequate supply of water and nutrients, which is why you should water and fertilize specimens cultivated in tubs regularly. Always keep the substrate slightly moist during the summer months, but avoid over-wetting - this can lead to rot. Excessive irrigation water must not remain in the saucer either, but must be removed promptly.

    Milkweed plants planted in the garden need protection from moisture in winter, while a layer of mulch protects them from drying out in summer. Fertilize the plants about every two weeks between April and September with a liquid container plant fertilizer. Hardy garden specimens, on the other hand, enjoy plenty of compost in April, June and the beginning of autumn.

    Prune milkweed properly

    Regular pruning of the milkweed makes sense for better branching and thus bushier growth and more lush flowering, especially since you counteract the perennial species in this way becoming bare. For a longer flowering period, faded flowers should also be cleaned off regularly. In addition, the pruning-tolerant plants can be cut back to a height of about 20 to 25 centimeters before being put away in the winter quarters, thus taking up less space. They sprout again in the spring.

    Propagating milkweed

    Milkweed can be propagated very well by sowing, proceeding as follows:

    • early possible from January / February
    • sow on seed compost or coco hum
    • do not cover, as light germinates
    • bright, but not in direct sunlight
    • Seeds germinate at 21 to 24 °C
    • Always keep the substrate slightly moist, do not let it dry out!
    • Germination period between three and six weeks
    • after pricking out

    The young plants can finally go outside from the end of May when the danger of night frosts has passed.

    Older specimens can also be propagated by division after flowering. To do this, dig them out together with the rootstock and divide them with the help of a sharp knife. Then put the individual pieces back in separately.

    hibernate

    Even if milkweed is often advertised as hardy: Most species are not or only partially so. These varieties die off above ground over the winter months, but usually sprout again from the underground rhizomes in spring. So that they do not freeze to death in the frost, you should cover the root area with brushwood in the fall. It is also important that the plant is protected from moisture during the cold season.

    On the other hand, non-hardy species or specimens cultivated in tubs should be bright and frost-free, but should be overwintered in a cool place at around 10 to 14 °C. Get them into their winter quarters in autumn as soon as the temperatures drop permanently below ten degrees Celsius. Water the plants sparingly in winter and do not fertilize them. In spring, temperatures of less than 12 °C or late frosts can be problematic: These delay new growth or ensure that the plant sheds its leaves. Then the flowering starts later.

    Hardy milkweed

    Only the types of milkweed mentioned below are sufficiently hardy and suitable for planting out in the garden:

    • Asclepias amplexicaulis: needs dry, sandy subsoil, grows up to about one meter high
    • Asclepias exaltata: growth height up to about one and a half meters
    • Asclepias fascicularis: adaptable species, occurs in mountains up to 2100 m, lavender to pink flowers
    • Asclepias hirtella: very adaptable, thrives on both dry and fresh soil, grows up to approx. 100 centimeters
    • Asclepias incarnata: swamp milkweed, height of growth up to 150 centimeters
    • Asclepias lanuginosa: woolly milkweed, native to Canada
    • Asclepias quadrifolia: Commonly found on mountain slopes in North America

    However, these species are also dependent on a favorable, sheltered location and light sun protection - such as a generous cover with spruce branches.

    diseases and pests

    Diseases rarely occur in milkweed, only root rot caused by too much moisture can be problematic. When in doubt, it is better to water potted plants too little than too much. Furthermore, the various species are susceptible to whitefly infestation. Aphids also like to settle on the large leaves.

    tips

    If the leaves turn yellow in the winter quarters, the plant is probably too warm. Temperatures of more than 12 °C during the winter break weaken the crop and lead to diseases.

    species and varieties

    Of the numerous types of milkweed, these are the ones that are cultivated here:

    Indian milkweed (bot. Asclepias curassavica)

    This species, also known as the Curaçao silk plant or silk flower, is not hardy and can therefore only be cultivated as a container plant or as an annual in the garden. Between June and August, the species, which grows up to 100 centimeters tall, delights with red-orange umbels of flowers.

    Milkweed (bot. Asclepias syriaca)

    The milkweed is also known as the parrot tree or parrot plant. because their unripe fruits are vaguely reminiscent of a budgerigar. The hardy species is suitable for outdoor cultivation, but can also be cultivated in a bucket. The plant reaches heights of growth of up to 200 meters, has large leaves and blooms in numerous pink umbels from June to August. The perennial, which is still rarely found in ornamental gardens, is a valuable bee forage plant.

    Marsh milkweed (bot. Asclepias incarnata)

    The marsh milkweed also magically attracts bees and butterflies. The species thrives in sunny to partially shaded locations on moist to swampy substrates. It is particularly suitable for planting along the banks of garden ponds or other ornamental water bodies.

    Tuberous milkweed (bot. Asclepias tuberosa)

    The species that blooms with eye-catching orange umbels of flowers - which is why it is sometimes referred to as orange milkweed - prefers stony, dry substrates and sunny locations. The species, which is popular in ornamental gardens, is only partially hardy in this country and always needs a light winter protection. However, it is also suitable for a tub culture, but must then overwinter protected from frost.

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Vegetable garden