Plants from the Asclepias genus tend to be either half hardy or hardy perennials.
Some of the common names for members of Asclepias include Butterfly weed, Milkweed, Orange Milkweed and Pleurisy root.
Milkweed plants normally flower in the summer.
Asclepias are often subshrub like in nature and the they range in size from 30 cm to 2 metres.
They are often grown as they are plants attractive to butterflies (especially the monarch).
Milkweed family members have clusters of blooms in red, orange or other hot colour's. They make an ideal plant to grow when trying to plant a natural looking or butterfly garden.
Asclepias tuberosa (Butterfly Milkweed).
Asclepias incarnata (Swamp Milkweed). Both photographs by Gmayfield10.
Common Names: Milkweed, Butterfly Weed, Pleurisy Root, Swan Plant Balloon Plant. Milkweed: Common; White; Whitestem; California; Tropical; Scarlet; Purple; Desert; Poke; Blunt-leaved;Narrow leaf; Heart-leaf.
Life Cycle: Hardy Perennial, Half Hardy Perennial
Height: 12 to 72 inches (30 to 180 cm)
Native: Americas, Africa, Europe, Asia
Growing Region: Zones 3 to 10
Flower Details: Many colour's, especially: Yellow, Orange, Red, White, Cream. Clustered flowers
Foliage: Dark green, lance shaped
Sow Outdoors: Cover seeds. Start of spring or autumn. Spacing 12 to 24 inches (30 to 60cm)
Sow Indoors: Chill seeds in the fridge for three weeks in peat pots (within plastic bags). Germination time: one to three months in the light. Temperature 55 to 75°F (13 to 24°C). Transplant outdoors before the last frost of spring or in the autumn.
Requirements: Full Sunlight or light shade. Sandy soils. Many species are drought resistant. Pinch back when 5 or 6 inches (12 to 15cm) tall to encourage bushy growth. Divide tubers in Spring; this is a risky process as roots are delicate.
When planting Asclepias outdoors it is best to sow out the seeds in either early spring or autumn, once sown, lightly cover the seeds with soil.
If you plan to start the growing of milkweed and other Asclepias genus plants indoors, then first you should imbibe the seeds in the fridge for three weeks in soil, then sow them in peat pots. Ideally you should do this 10 weeks before you plan to transplant them outdoors, normally in the late spring (or at the beginning of Autumn).
Germination of milkweed seeds normally takes about one to 3 months and should be performed at a temperature between ten and twenty degrees Celsius.
Outdoors the seedlings should be planted about 40 to 50 cm apart in partly shaded to fully sunny parts of your garden. Asclepias prefers to grow in a sandy soil, but will grow in most non-heavy soils.
Milkweed is very easy to look after, pinch back the heads when about 12 cm high, this will tell auxin hormones to make more heads (instead of having a single flower). If you require more Asclepias plants then you should (very) carefully take root cuttings in the spring.