organic control of squash vine borers

[Jiminct]

For the first time in 15 years of gardening I had no problems with the squash vine borer. In the past I've shot them out of the air with elastic bands, picked their little brown egg off the stem at the base of the squash plant, tried aluminum foil around the stem, and cut the larva out with a razor and even blasted the moths with a CO2 pistol to stun them. All with limited success. I tried two new things last year and I'm not sure which was the winner. At the end of the previous season, I collected all the somewhat decayed vines of all my squash plants, dumped them in a metal wheelbarrow and submerged them with boiling water. The other thing I tried this last season was to spread a thin layer of tanglefoot (tub version) on the base of the stems of all my yellow summer squash and zucchini about a week before I normally see the vine borers (mid July here in CT). I cleaned the base of the squash vine of any dirt and cleared away any clutter (grass, small withered squash leaves, small weeds, etc.). The first few inches away from the soil is where I usually see the moth and find the egg on the vine, so that's where I used the tanglefoot. Since the vines are almost horizontal at this time of the season, I just coated the upper surface of the vine. I suspect the moth does not like getting her feet stuck and even less trying to lay an egg in the sticky goo. I would be very interested in hearing if people have success with either of these methods. I also use the tanglefoot as a barrier on my fruit trees to limit access of ants and earwigs.

[Lindsaylew82]

I have to go research tangle foot!

By the time we are pulling our plants out of the ground here in SC (which is usually early August) we have so many SVB and squash bugs that we burn them. I've found that to be perfect for taking out any of next year's producers. They always come back. Likely because NO one else around here does it. SVB and squash bugs, and pickle worms, are constant here, but I can usually get a good crop before the damage gets too severe. My plants tend to produce even after they've been infested. I hand pick daily, they're always replaced! I neem weekly, and honestly, I really think that's very helpful.

Guinea Hens are very useful... So I've heard. I've no experience with them though!

[rainbowgardener]

I am for sure going to try the tanglefoot-- where do you buy it?

Other people have said that about plants producing after the SVB's bore into them. That has never been the case for me. My experience with zucchini has always been that it grows a big beautiful bush/ vine, produces one or two fruits and then the SVB's get it and it collapses and withers away to nothing very quickly.

I have tried burying the stems, wrapping them with aluminum foil, keeping row cover over them (which works until you have to open it up for the flowers to be pollinated) and never succeeded in getting more than the first fruit.

[Jiminct]

I purchased it at my local True Value Hardware store, but I believe Walmart carries it--or you could look for it on line (Amazon, Tanglefoot Company, etc.

[Jiminct]

I had a couple of other ideas which I haven't tried yet but which might be useful. The first is to use the aerosol tanglefoot to lightly coat not only the base of the plant but some of the leaf stems as well. I'm thinking that maybe the moth might lay her egg if the tanglefoot isn't too thick, but the larva would get its jaws gummed up in trying to get inside the stem. This might affect the squash bugs too. Don't spray the flowers. The other idea is to pre-slit the stem to remove the protection offered by the outer layers of the stem.

[Jiminct]

I thought I would try posting a picture. Haven't done this before!

[Lindsaylew82]

Nice! Is that with the tanglefoot?

My squash are currently refusing to emerge from the ground....

[Jiminct]

Yes. The tanglefoot shows up on the base of the plant over on the left near the weed mat. Interesting that it is almost a 2 megapixel picture but only displays at 41K pixels. I guess it would take way too long to download to interested viewers if left at the original resolution. Also, if you place your cursor over the picture it will display some info about the picture.
You have some smart squash plants if your weather is anything like ours. We've had weather up into the 70's but some nights are still going down below freezing. I don't plant squash until the middle of May usually (here in CT) although last year it was a few weeks earlier.
It was two pictures 'cause I pressed the 'Inline' button twice. I'll know better next time.

I can hardly wait for the start of the growing season!

[Jiminct]

Saw the first squash vine borer of the season today (July 7th in CT). She was resting on a zucchini leaf and I hit her with a bug zapper. I heard the zap but couldn't find the body. I forgot to mention that the squash last year did not taste any different than normal, but for those who might want to try the tanglefoot, and are afraid there might be a 'bleed through' into the squash you might want to wrap the base of the squash plant with tape or barrier of some sort before applying the tanglefoot.

[Jiminct]

August 10th update. Because I used a fair amount of tanglefoot last summer, I decided to use less this year and just drizzled a bit on the bases of the zucchini and yellow squash to see if it would still have a protective effect. Over the last several days, I'm noticing frass on the bases of 15 of my 50 plants (25 zucchini and 25 yellow squash). I find that I can easily trim off the damaged sections with my knife and the squash appears to be fine. Most of the larva I find are less than a half inch long and very thin. Entrance to the plants are being made where I didn't cover with the tanglefoot, particularly where the leaf stem joins the main stem. I tried to place the tanglefoot so as to prevent the moth from landing on the main stem, but as the lower leaves wither, it seems to open up an avenue for the moth. For the last three weeks, I've averaged 7 to 12 zucchini a day and about that for the yellow squash, so I feel that I've had a successful season and that the tanglefoot really does work. I'm thinking that the odor of the tanglefoot may have a deterring effect as well as the stickiness, so, with time, it loses its effectiveness. Feel free to respond with suggestions!

[rainbowgardener]

I got spray on tangle foot and have used it on my new yellow crookneck squash plants. I have just done it once so far, but I can see that the spray will need to be renewed as the plant grows and more stems appear.

Thanks for the info! If this works I will be eternally grateful! I already lost two acorn squash plants to the SVB's -- I was under the mistaken impression that acorn squash was resistant, but it is not. I have never been able to grow summer squash because of them. I will be so excited if this makes it so that I can.

[Jiminct]

I talked with my son tonight and he told me he had tried the spray tanglefoot on his squash plants and did not get good results. The leaves yellowed and died. He thought that the solvent used to thin the tanglefoot so it could be sprayed was the culprit. I bought an aerosol can but haven't tried it yet. Guess I'll stick with the tub version. Sorry for the bum steer--hope you didn't use too much and that it doesn't hurt your plants. Also, my plants were about 6 or 7 weeks old when I used the tanglefoot--not sure what effect it would have on very young plants. Please let me know how it turns out.

[pepperhead212]

I am going to have to try this next year - thanks for the info! I have been unable to grow non-moschata squash since the 80s, and I assume there is a native plant that is also a host plant, which is my problem with pepper maggots. I once applied Surround, which got me more squash than anything, but I had the same problem I can see I'd have with tanglefoot - had to be appplied to new growth frequently.

[rainbowgardener]

Yes, I can also see the tanglefoot will have to be reapplied to new growth frequently. If you had a field of squash, probably not a workable solution, but for those of us with a few plants, not too bad.

Yes, I can see the spray on was probably a mistake, although certainly less messy to handle. I had three little squash plants. One was very small. It was apparently too tender and just up and died when sprayed with the tanglefoot. The other two are doing fine, but I have to be careful only to spray the stem. Leaves that get sprayed crumple up and turn brown where the spray hits them. If I buy it again, I won't get the spray. But I'm still waiting to see if it actually works to prevent the borers. (Seems like it might. It is very sticky and it does not wash off when the plants are watered.)

[Jiminct]

In my experience, the larvae are always found on the base (stem) of the plant within six inches of where the plant enters the soil. One good application at the base(see picture I posted), possibly coating the first few leaf stems for an inch or two away from the main stem should be all you need to do for the season (if the borers in your area are like mine). Last year, most of my plants died from old age and powdery mildew. Even though I used much less tanglefoot this year, most of my plants show no vine borer damage, but the ones that do, the frass is within a few inches of the soil line. I suppose that if there were a huge number of borers they might go after the upper parts of the plant but I'd hate to see you waste a lot of tanglefoot if you didn't need to.

[applestar]

Just as an added info, SVB moths lay eggs on other parts of the vine besides the near soil level. My trellised volunteer C.pepo squash is getting infested 4-5 feet in the air -- often from side of the hollow leaf stems -- they enter then head to the base of the leaf where the stem attaches, which is not too bad since the dying leaf indicates their presence and can be eliminated -- but when they head to the vine and leafnode, they can enter the vine with within the leafstem. Also boring into hanging fruits via the fruit stem and side if the fruit skin is still tender enough.

I'm curious to see how your experiments turn out. This year, my impression with vulnerable varieties has been that summer squash that are harvested immature is not as much of a problem when its a fast maturing cultivar and is started early -- I got more than enough Butta zucchini harvest before they have been taken down. It's the winter squash that are difficult because they don't often make it to mature fruit. I think I have one mature volunteer that looks like cross between carnival and delicata. 2nd one might be mature as well. 3rd one is still on the vine but I doubt it sill make it to maturity. I don't think even the biggest Kakai is fully mature enough to have plump seeds since point of Kakai is mature seeds. But all three fruits will be eaten in sauce and soup/stew, and for that hulless seeds are very useful, even if the flesh is not the best eating quality. And the rind is edible, too, and will be more nutritious since they are still very dark green. (Benefit of organic growing plus not using manure, etc.)

But if you have the space, and you can get just ONE mature fruit per winter squash plant, you might still get enough to call it a good harvest, though its a frightful waste of space for us with small growing area.