What is on my Brussel Sprouts?`

Asked July 18, 2019, 6:45 PM EDT

I've seen this before on other plants in my garden, but this year my brussel sprouts are the victims...looks like ash, but I can't tell if it's little bugs on the greens? help!

Washington County Oregon

3 Responses

The new growth of the broccoli is thickly coated with aphids. They suck plant sap, deform leaf tissue, and weaken the plant. Plants most at risk are those which have received excess nitrogen fertilizer and /or are stressed. The recent warm weather may have contributed to the latter.

Use a harsh water spray to blast the aphids from the plant. Repeat as needed, perhaps daily, because many are protected within the deformed leaves.

You might also use commercial insecticidal soap, following label directions. Again, repeat as needed. But don't spray if the temperature is, or will be, 85 degrees or higher the same day.

Wow! Thank you so much...this is actually my first attempt at brussel sprouts-will these aphids affect the growth? I'm at work all day today, but i'll be sure to clean them off as much as possible tonight. Would it help me to buy lady bugs and put them in my garden? I don't notice them on any other plant...is there a reason they chose the brussel sprouts?
You are awesome! I love learning about this stuff and really appreciate your knowledge! Thank you!
Brandy Kelly

The aphids are already affecting the growth because the leaves are deformed.

Purchased lady beetles aren't helpful because they fly away when they are released. Your best tactic is a walking through the garden every day or so to determine, what, if anything, has changed. Then, when you see aphids, either squish them or blast them off the plants with a harsh water spray.

Some aphids are specialist. That is, they attack only one kind of plants. Those on your broccoli are cabbage aphids which attack all of the cole crops when the conditions are right.

You might like to review "Growing Your Own." It's a tabloid about growing vegetables. (The general info also applies to growing flowers.) Especially useful is the planting chart on page 8. Download it from https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/em9027.pdf