Asclepias is a plant genus that is part of the Apocynaceae family. It contains about 120 species of flowering plants and herbs commonly referred to as milkweed. The name describes the characteristic milky residue that usually exudes from the plant when the stems or leaves break. Most species have clusters of small flowers that give way to green fruits, which usually ripen to a yellowish-brown. Plants within this genus naturally grow among grass and are susceptible to pest damage.
Nearly all plants in the Asclepias genus are toxic to a certain extent. The sap of the plant is very sticky, almost glue-like. It contains many dangerous chemicals including resinoids and cardiac glycosides, which if consumed, can cause symptoms of poisoning including vomiting, weakness, and spasms. Animals which consume the plant may die. In addition, the plant may absorb toxins from the environment including herbicides and pesticides.
Although plants within the Asclepias genus are dangerous, gardeners use them for a number of reasons. The obvious one is for their brilliant flowers, which bloom in a variety of colors, depending on the species. Asclepias viridis features green blossoms from April to September, while Asclepias tuberosa showcases orange and yellow flowers from May to September. Most species have fragrant, nectar filled flowers that attract butterflies. Also, the plants are deer resistant.
Usually, these species are planted with other mid-sized perennials in a butterfly garden or a wildflower garden. They also do well as border plants or as a spread in open meadows. Additionally, gardeners may grow the plants in pots.
Plants within this genus require fertile, well-drained soil. Most species are tolerant to drought but do require regular watering for optimum growth. Also, exposure to direct sunlight is recommended over partial shade.
Whiteflies and spider mites are usually responsible for insect damage to plants within the Asclepias genus. Whiteflies are found on the underside of leaves and are generally active during the day time. They feed on the sap of the plants and usually leave behind a sticky residue called honeydew. Spider mites typically discolor leaves and create a speckled appearance.
Some ways to control infestation is to introduce predatory insects to the garden, such as thrips or lady beetles. Another way to eliminate whiteflies is to use traps which attract and hold them. Spider mites may require the use of miticides, which are chemical sprays that target mites.