Are you dealing with milkweed fungus, leaf spot, and other issues not caused by annoying milkweed pests? Then you’ve come to the right page…
Over the years, I’ve been less concerned about what’s ailing our milkweed, and more concerned about treating it early. This strategy has worked well to keep our milkweed patches healthy and ready to support monarchs.
1. Remove sick leaves– Whenever you come across sickly milkweed leaves, remove and discard. When it make sense, prune away entire sections of the plant. Do not compost diseased leaves/stems and risk spreading fungus spores into the soil.
2. Thin out the herd– if your milkweed plants are crowded, your milkweed patch can become a breeding ground for fungi. If you don’t have milkweed to spare, you can transplant what you remove:
3. Water at the base of the plants– this is less necessary if your plants have good air circulation.
4. Spray spores away– spray milkweed plants and the surrounding soil with a hydrogen peroxide mix (4 parts water to 1 part peroxide) to kill fungus spores:
Hydrogen peroxide also adds more oxygen to the soil to prevent root rot. It can also prevent another common fungus that causes milkweed to wilt and die.
5. Replenish their milk?– for fungi similar to blackspot, try this simple rose remedy after removing the affected leaves:
note: If you’re spraying sickly milkweed and notice webbing on the plant, you’re probably dealing with microscopic (almost) spider mites and can check out our milkweed pests page for specific treatment options.
This bacterial disease is spread mainly by leaf hoppers and is recognized by yellowing leaves with twisted shapes, and die back of branches. Plants affected by this should be immediately removed and discarded. If left for the leaf hoppers, they’ll quickly spread the bacteria to other plants in the vicinity.