My questions are: 1) When will the cabbage butterflies die off/stop laying their eggs? 2) Is hosing (and squishing the larvae) going to be enough to save the crop; 3) Should I try covering the plants with row cover fabric, or would it just be a wasted effort for this season?

Thanks!

The eggs are small, slightly elongated, off-white and sit on end. Look for them on the backs of the leaves. Squish when found.

And yes, remove the cats you see, then repeat.

And put row cover over the plants but be certain to check now & then for at least the first week because you will have missed some of the eggs & the very young cats.

Then resolve that next year you'll add the row cover when you plant, securing all edges.

And they will start all over again in early April, but later in zone 4.

I MacGyvered a row cover out of repurposed drip irrigation tubing, PVC slip junctions and t-connectors, bridal tulle fabric, and strips of scrap lumber. Too bad I can't post a pic, 'cause I think it's pretty slick (as well as economical). I'm calling it "Death Camp for Caterpillars," and will refine it over the winter so it can go on when I set out the new plants next Spring. Very glad to learn that the butterflies' days are numbered since first frost isn't supposed to arrive here until mid-November.

I am also trying spinosad spray from the nursery on the leaves and hearts of the plants, though I wonder how effective it will be with all of the hosing I'm also doing. And some of the caterpillars either have a disease (they're fatter, whitish, and unmoving), or they're actually something else, like slugs.