floating row covers for SVBs?

[danflester]

I'm looking at zukes and cukes this summer. Did OK last summer with BT injections to control squash vine borers, which are endemic here, but was kind of a pain in the neck even in a very small garden, and I'd like to expand. I'm looking to do floating covers this summer, which I've never done before. In anticipation of that, I have a few questions for people who use them routinely. BTW, I'm in central Texas.

Of the different brands available, different weave and different materials, what works best? Minimal shade, maximal ventilation, yet keep the buggers out. Ideally reusable.

Hints about deployment? How tightly do the edges have to be sealed? I'd like to just have a couple of rocks holding down the corners.

This stuff is often sold for frost-proofing, and sellers proudly state that temps under the cover can be 15-20F above outside temp. I DO NOT want that in a Texas summer! With this in mind, as per the above questions, what do I need to know in selecting the covers?

Are these only sold in rolls? Large square sheets (as in, say, 10x10 ft) might be optimal for me.

Anyone have success against SVBs just with regular spraying of BT? That would be easiest, but I've heard that if you don't inject it, don't bother.

[desertgardener]

I use row covers when starting seeds in the spring. Keeps out birds and bugs until the plants get established. I haven't tried using it all summer but I think you'd run into several problems. If you get light enough material so it won't get too hot under there, it will tear easily. Unless you've got squash and cukes that don't need pollination, your pollinators won't be able to get under there either, and you won't get any fruit. It's hard to get fabric big enough to cover a mature plant; I don't know what types you plan on, but covering a mature zucchini or a sprawling cuke vine would be tricky. The zucchini types I grow tend to have rather prickly stems and leaf edges which would get caught on the very lightweight fabric. I also find it very annoying not to be able to see what's going on under there without uncovering the whole thing, then recovering it...lot of work. You may not find it a bother. That said, they provide great protection against critters. If you want to try it, Peaceful Valley Farm Supply sells a big variety of weights and sizes. I haven't done any cost comparison this year but last time I bought it they were far and away the best price. Search their site for Agribon. If there's any wind in your area at all you'll need more than just a couple rocks. It is pretty windy where I live and I have to weight the stuff down with a brick about every two feet of row. I buy rolls about

6' wide for a 4' wide bed, and cut it off so there's about 18-24 inches of extra fabric at each end. Even with all those bricks we once had a little-bitty dirt devil that ripped the fabric from under the bricks and took off with it. I have also found that very soft seedlings can be rubbed off if the fabric is moving, as it does when the breeze comes up. I now hold it up over my pepper seedlings, but I haven't had trouble with peas, beans, corn, or greens.

Cyndi

[danflester]

pollination, and having to pull the thing off whenever I wanted to inspect or water (no drip system) and I actually had not considered that these plants are indeed spiny enough that they would probably snag on the fabric. Although I don't like pesticides much, I might just spot-spray, or perhaps even paint, the large stems with Sevin or maybe some pyrethrin. As long as I keep that stuff away from the flowers (such that the pollinators don't croak, and the stuff isn't all over the fruit) I guess it should be OK.

Wow, the source you pointed to is sure a major outlet for the Agribon sheets which, it seems, is the definitive material here. Now I know what to ask for! It even comes in different weights, which I had never realized. I gather that the heavy stuff is for frost protection, while the lighter weight stuff is for pest management.

[Pat Kiewicz]

In my past experiments with summer row covers, I found that sometimes I was trapping pests under the covers. Unsupported fabric, even though it was lightweight, wore on the plants. Lack of air circulation encouraged fungus. And then there is the problem of nothing getting pollinated under the cover.

I did really well last summer with a combination of hand inspection and removal of eggs (when the plants were small) and pyrethrin sprays *carefully directed on the stems* (especially near the base) once the plants got too bulky to hand-inspect.

Bt injections are best reserved for use if your first line of defense fails to stop the SBVs before they get into the stem.

(Yesterday I spent much of the day cooking, mashing, packing and freezing squash from last fall's harvest. Today, pumpkin waffles for breakfast! With home-made spiced apple jelly!!)

[danflester]

In fact, someone just told me that if you've had SVBs in the past, the progeny are likely in the soil underneath, so tight row covers just protect them.

Yep, I think I'm convinced. Hand inspection can be pretty time consuming, but carefully directed spraying is a strategy that I'm willing to adopt.

Wonderful! Congratulations on your harvest. Pumpkin waffles sound like a great idea.