Current buzzwords in the world of gardening include pollinators, butterflies, natives, and monarchs. It seems that everywhere I look I read something about the importance of pollinators and how we can protect them.
One of the best plants for pollinators, especially butterflies, is milkweed. My colleague Candice Miller, Horticulture Educator in northern Illinois, recently posted the following blog about milkweed.
While the name "weed" in any plant name scares many gardeners, milkweed plants add beauty to the garden and are essential for providing habitat for monarch butterflies. Monarch butterflies lay their eggs on the leaves of milkweed plants because their larvae only feed on these leaves. These larvae then go through metamorphosis to transform into an adult Monarch butterfly.
Milkweeds of any kind make a great addition to the garden and there is a species for just about any type of growing condition that you may have.
Asclepias tuberosa, Butterfly Weed, grows easily in average, dry to medium, well-drained soils. It prefers full sun and is also drought tolerant which makes it low maintenance. It grows 1 to 2.5 feet tall and will spread about 1 to 1.5 feet. It has clusters of bright orange or yellow-orange flowers from June to August. The attractive flowers of butterfly weed attract many species of butterflies besides monarchs.
Asclepias incarnata, Swamp Milkweed, prefers to grow in medium to wet soils in full sun. This species of milkweed is native to swamps and wet meadows as its name suggests, and it works well in rain gardens. It grows 3 to 4 (sometimes 5) feet tall and will spread about 2 to 3 feet. Its clusters of flowers can be white, pink or mauve, and also attract many species of butterflies in addition to monarchs.
Others include the Common Milkweed (Asclepias syriaca) which tolerates moist, well drained soils to dry soils, Whorled Milkweed (Asclepias verticillata) which is white flowered and tolerates dry soils, or Balloon Plant (Asclepias physocarpa) which has unusual round seed pods.
Milkweeds take a little work to start from seed, but once they germinate they thrive and sometimes self-sow in the garden. Milkweed seeds need to go through a cold period in order to germinate, so either plant them in the fall or put them in the fridge for 30 days prior to planting.
Milkweeds are a great flower to add to the garden, but they can get a bad rap for being slightly aggressive. To prevent milkweeds from self-sowing throughout the garden, simply collect the seed pods before they split open freeing their seeds. You can then collect the seeds to add them elsewhere in the garden or to pass along to friends to attract butterflies to their gardens.
The University of Minnesota has more information on growing milkweed for monarchs at http://www.monarchlab.org/Lab/Rearing.