Little understood fact is that ladybugs are unable to do much good on milkweed. Aphids, sensing the danger, begin producing volumes of even thicker, stickier 'honeydew', flooding the poor ladybug with the glue-like substance.

i gloved up and mushed as many as i could. will repeat weekly (or as often as needed) until they are under control :)

This is my first year with milkweed plants, though mine are A. tuberosa. Around six weeks ago I started to see large numbers of aphids on some of them, while others were mostly untouched (I've got about 10 plants started from seed this spring).

One day I did the hose-blast thing and washed most of them off. After that I got to thinking that battling aphids just isn't something I want to do with my life. I left them alone, figured I'd give them a couple of summers to see if natural predators would take care of them.

Fortunately this year something killed off the aphids. I saw some ladybugs around, but also a number of tiny flying bugs that I didn't take the time to identify. It took several weeks, and during that time it was a little hard to look at the aphid-infested plants. I didn't check them every day, but it did seem to me that in the end the aphids disappeared pretty quickly.

Here are a couple of hypotheses:

1. Leaving the aphids alone means that there's plenty of food for predators, which gradually increase their numbers until they're able to catch up with the aphids.

2. Having other native plants around provides diversity that may help sustain beneficial insects. My milkweeds are in a bed that includes plants like slender mountain mint that seem to attract a variety of insects.

But it could have been any number of things -- weather, etc. We'll see how it goes next year. I plan to add swamp milkweed next spring, though in a different location.