Asclepias incarnata
Swamp Milkweed, Asclepias incarnata, originated in America. There are two varieties – one has white flowers, one has pink flowers. We have the variety with pink flowers.
Swamp Milkweed is not affected by frost over winter and once established will provide good supplies of feed in the early part of the season while you are getting your Swan plant seedlings up to a reasonable size. But the plant may not be suitable as your sole source of food for Monarch caterpillars as it loses its leaves before the last of the caterpillars have finished feeding.
The plants can be propagated either by seed or by division of the rhizomes of a mature plant.
Plant seed as soon as possible into seedling pots or seed trays – and then prick seedlings out into larger pots when they have 2-3 true leaves. First year plants will normally only have a single stem but in following years will produce multiple stems as the rhizomes develop. Light browsing by caterpillars is okay in the first year but ensure that there is a reasonable amount of foliage retained to enable the plant to develop a strong healthy rhizome mass.
In late autumn the plant will lose its leaves and stems will die back. It is not dead; just mark the spot with a stake and wait for new shoots to come up in the spring. If the seedling appears to die when planted out into its permanent position do not be hasty in replacing it. In most cases you will find it will resprout.
If you want to share the rhizomes, carefully dig up the mature plant after all the shoots have died back and divide up the rhizome mass into smaller portions and replant.
Packets of seeds are $5, contents 20-30 seeds.
