Pest identification
What's eating my common milkweed?
Oleander aphid / milkweed aphid (Aphis nerii)
Signs: Dense bright yellow colonies on stems and leaf undersides; sticky honeydew attracts sooty mold; heavy infestations stunt new growth
Control: Knock off with strong water spray; hand-crush clusters wearing gloves; encourage natural predators (ladybirds, parasitic wasps); avoid insecticides which also kill monarch caterpillars
Large milkweed bug (Oncopeltus fasciatus)
Signs: Adults and nymphs cluster on seed pods feeding on developing seeds; sap feeding causes pod distortion
Control: Hand-pick bugs and drop into soapy water; remove infested seed pods if seed harvest is a priority; populations rarely threaten plant survival
Deer
Signs: Young shoot tips and leaves browsed, especially in spring when fresh growth first emerges
Control: Deer repellent spray on young plants; physical fencing around new plantings; established plants with multiple stems tolerate browsing and regrow quickly
Keep common milkweed pest-free
Healthy plants resist pests best. Get the basics right:
Common Milkweed pests — FAQ
What is eating my common milkweed?
Common Milkweed (Asclepias syriaca) hosts monarch butterflies, so most leaf-eating caterpillars here are welcome guests. The real pest problems are milkweed aphids (bright yellow), oleander aphids, and milkweed bugs. Large milkweed bugs feed on seeds. Deer and rabbits browse young shoots. Avoid insecticides to protect monarchs; hand-remove aphid clusters instead.
How do I get rid of oleander aphid / milkweed aphid (aphis nerii) on common milkweed?
Dense bright yellow colonies on stems and leaf undersides; sticky honeydew attracts sooty mold; heavy infestations stunt new growth Knock off with strong water spray; hand-crush clusters wearing gloves; encourage natural predators (ladybirds, parasitic wasps); avoid insecticides which also kill monarch caterpillars
How do I get rid of large milkweed bug (oncopeltus fasciatus) on common milkweed?
Adults and nymphs cluster on seed pods feeding on developing seeds; sap feeding causes pod distortion Hand-pick bugs and drop into soapy water; remove infested seed pods if seed harvest is a priority; populations rarely threaten plant survival
How do I get rid of deer on common milkweed?
Young shoot tips and leaves browsed, especially in spring when fresh growth first emerges Deer repellent spray on young plants; physical fencing around new plantings; established plants with multiple stems tolerate browsing and regrow quickly