Milkweed (Asclepias syriaca)

Milkweed (Asclepias syriaca) Information

By Ronnie Dauber, Garden Guides Contributor Common Milk Weed is a perennial that is a nectar source for many kinds of bees including Honey Bees and Spider Wasps, and a larvae food source for Monarch butterflies. Although it is a weed that most gardeners prefer to do without, the plant is very different from many of the other turf weeds as it has very low tolerance to the elements that make other weeds aggressive and domineering. There are over 100 species of Milk Weed, the plant that has earned its name from the visible milky white latex that exudes when it is broken.

General Characteristics

This is a heavy-stemmed perennial that reaches a height of between 2 1/2 and 5 feet tall. It has large oblong/elliptical leaves that are arranged opposite with entire margins that are smooth. It reproduces through seed and forms a distinctive grey/brown seed pod. In the spring, the Milk Weed produces flowers which are greenish-pink to greenish-white umbels.

Growing Conditions

Milk Weed grows best in well-drained soils and in locations where the ground is undisturbed such as naturalized areas. It is often found in natural or boundary areas where there is low maintenance such turf mowing or pruning. It requires full sun and can survive in partial shade. When the stalks are broken or mowed, the plants struggle with little ability to grow back, but will continue to stay alive through its stored energy of rhizomes.

Cultivation and Care

The Milk Weed requires little to no maintenance to continue growing. However, it cannot take any physical damage or abuse such as being mowed over or cut back. The plant itself will not die from this, but it will not grow back until the next year.

Weed Control Techniques

The Milk Weed plant could be removed by hand-picking it; but that would only remove the visible plant and would not affect the root that likely would not come out with it. It would appear that in the season it was pulled that it would be gone but the fact is, the roots are still alive and will grow back in the following spring. Single or repeated applications of herbicides have little to no effect on Milk Weed plants or remains of roots. The most effective way to get rid of Milk Weed is to spot-treat every 21 to 28 days with glyphosate.

About this Author