Grow Heart-Leaf Milkweed for Monarch Butterflies!
Heart-leaf milkweed is the common name for Asclepias cordifolia. It is one of the milkweed plants on which Monarch butterflies will use to feed their caterpillars. Monarchs will only use certain species in the Milkweed family on which to lay their eggs and Asclepias cordifolia is one of them.
About Asclepias Cordifolia
Asclepias cordifolia is a perennial that will die back in the fall to return in the spring. It is hardy in USDA zones 7-10. Heart-leaf milkweed grows about 1-3 feet high and has lovely heart-shaped blue/green leaves that are tinged with purple. It is unique in that it is one of the more colorful milkweed species.
The flower buds have a dark purple/burgundy look to them which open to reveal burgundy petals highlighted with a white or pink corona. The flowers appear from June-August and are followed by seed pods which are tear-drop shaped and also tinged with purple.
Heart-Leaf Milkweed Growing Conditions
Asclepias cordifolia is native to only a small region of the United States which includes California (mostly the northern half), Nevada and Oregon. It likes full sun or partial shade and is drought tolerant. Heart-leaf milkweed does well in medium to course soil (or rocky soil) and thus prefers soil with good drainage.
I do not have personal experience growing Asclepias cordifolia in my South Carolina location so I cannot speak for how well it may grow outside of its native area. This fall/spring will be the first time I have offered seeds and will try to grow it myself. I have searched for information about how well it does outside of its native region but have found very little. Because of this I suspect it may not grow well elsewhere.
I intend to try it though since burgundy/purple is one of my favorite colors and I enjoy the challenge! I would love to hear from you if you have experience growing Heart-leaf milkweed outside of CA, NV, or OR.
How to Grow Heart-leaf Milkweed from Seed
As with researching how well asclepias cordifolia does outside its native region, the information is sketchy for growing it from seed. We have found from personal experience that it needs about 2 months of cold stratification which is the process of breaking dormancy by exposing the seed to cold and moist conditions. This also makes it a candidate for planting in the fall or winter-sowing.
In my experience the seeds have germinated when planted at a depth of about 1/4 inches. They take longer to germinate than some other milkweeds. They take about 3-4 weeks. The germination rate is above 50% but I do not have an exact percentage.
Buy Asclepias Cordifolia Milkweed Seeds and Plants
If I were butterfly gardening in CA, NV, OR then this pretty milkweed would be on my list for attracting Monarchs! However, I intend to give it a try anyway. If you are not located within the native region of Heart-leaf milkweed and want to stay with milkweed that is native for you, we have other milkweed plants you may want to consider. Milkweed plants will bring the Monarch butterflies to your garden, and the eggs, caterpillars, and chrysalises are so easy and beautiful to raise indoors or just watch in the garden.