I'm a Cucurbit failure :(( ... Zucchini tutoring please!

[Delilah]

Darn it! Having finally mastered the Downy Mildew with milk spray, my big fluffy Zucchini plants have all decided to die from some kind of fast-acting root rot instead .

They've been through days and days of rain before, but this time for some reason they died after the rain! Grrrr... It' Spring time here, BTW.

So, as that was my fourth round of attempted Zucchini-growing in 12 months, involving four different types of Zucchini in three locations, not to mention all the Cucumber and Squash plants that met the same fate, and I have still not harvested a single one ... I need expert tutoring please! Someone please teach me how to get those wonderful harvests of shiny Cucurbits that the seed packets promise!

[gumbo2176]

Delilah, it sounds to me like you may have an infestation of the dreaded Squash Vine Borers. If the plants look like they are rotting near the roots and the heavy stems are split open with a light brown mess coming out of them, check the plants for borers. Take a knife and split one of the affected stems and see if you find a large maggot looking critter in there. If so, it is the vine borer. I've had this problem twice this year and lost all my squash plants to them. I currently have new plants in the ground and they are producing well since we are now heading into the fall months.


If you do find the borers in there, do not put the plants in a compost pile. Better to burn them or toss them in the trash.

[rainbowgardener]

exactly what I was thinking, squash vine borer aka zucchini root borer. I do't know if you have the same pest varieties there in australia as we do, check with someone local about it. Type squash vine borer in the Keyword box that comes up when you click on Search the Forum and you will find tons written here about it. The most destructive pest in the garden, IMO. I have a really hard time growing zucchini because of it. It is easier to grow acorn squash and butternut, because the SVB's don't like them as much.

I did a little better this year, by wrapping the bottom few inches of the stem in tin foil and growing it under row cover until June (often the SVB's are mainly around in spring and are gone by summer), but ultimately the SVB's got them anyway... but at least I got some zucchini first this year.

[Canadian Farmer Guy]

Be sure to rotate your crops.
Planting the same thing, in the same spot, over and over can cause problems.

Keep trying, fried Zucchini are one of my favorite summertime treats.

CFG

[Delilah]

I looked them up - yech! Lovely creatures.

Yes, they do exist in Australia as a major pest and so I fear you may be right . I'm so frustrated by it - I want Zucchini, darn it!!! I was hoping I had just done something wrong.

I found this useful(ish) link: https://attra.ncat.org/attra-pub/squash_pest.html ...but because I can't use row covers I'm not sure what the best combination of other strategies is for a home garden.

[garden5]

I'm not sure if anyone else mentioned this, but a sure sign of the SVB (squash vine borer) is "frass" coming out of the base of the stems. This looks like damp sawdust and doesn't smell too great either.

As RBG mentioned, using aluminum foil at the base of plants helps and crop rotation is great as well. Another thing you can do, if your growing season allows, is plant a second crop a few weeks after your first one. This way, by the time the second crop is mature, the SVB will have moved on in their life-cycle and will no longer be much of a threat.

[gumbo2176]

[quote="garden5"]Another thing you can do, if your growing season allows, is plant a second crop a few weeks after your first one. This way, by the time the second crop is mature, the SVB will have moved on in their life-cycle and will no longer be much of a threat.


garden5 I wish it was that easy for me. I tried planting zucchini and yellow squash 3 times between spring and mid summer and every time I lost the plants to SVB's. I planted another half row of them several weeks ago and so far I've gotten a couple yellow squash but the zucchini fruit are being hollowed out by a green borer similar to a SVB but much smaller. This is a new one to me since they are only attacking the fruit and not the plant. I resorted to spraying with Spinosad today to see if I can salvage the blossoms that are trying to make more fruit.

[lorax]

Delilah, if you're having problems in-ground, try potting the plants up in nice big containers using fresh store-bought soil and then cover them with fairly fine garden mesh in tent-type cones - I've avoided SVB (which is a major problem here as well) neatly that way. You can also then train the vines to climb, which helps prevent blossom-end rot and other mooshy fruit problems. My Zucchs seem to love it when I feed them seaweed.

I grow two types of Zucch - "Grey" and "Black," both of which are terrific high-heat perfomers (which is necessary, since our temps here can rival the Nullarbor in summertime), but my last set of plants was done in by a big windstorm, which snapped them off at the base.

[Delilah]

Now I'm starting to wonder... I went to have a close look at the one I pulled out yesterday. It was so mushy and destroyed. I couldn't see obvious signs of Borer activity. Does Death By Borer produce sudden collapse of a plant - general mushiness that knocks a plant down within a few days?

Another Zucchini nearby, which is still standing but not looking great, also didn't have obvious Borer entry points on quick inspection. What it does have is a narrow, shrivelled, greyed and twisted stem for the 12" closest to the ground. What's that all about?

It doesn't look as though it could get much nutrition through that skinny umbilical-cord-like stem, but it is still currently putting out flowers.

[rainbowgardener]

Yes, death by borer takes a big healthy plant and turns it into a wilted shriveled mess in just a few days. It's like your plant just disappears before your eyes.

But what it does not do is hollow out the fruits; the SVB's stay in the stems and just cut off the plant's circulation. The whole plant dies because it can't get any fluids/nutrients. Because it is not getting fluids, it tends to be more shrivelled than mushy.

If you have hollowed out fruits, you probably have some other pest (of course you could have both, lucky you! ).

It is very frustrating, some people write about how easy zucchini is to grow and how productive. Not true for those of us who live where there are lots of SVB's. The zucch seems to be way more vulnerable to these pests than say peppers and tomatoes and other things I grow.

[Delilah]

What do you make of the narrow, shrivelled, grey and twisted stem on my remaining plant? Is that late stage SVB or something else altogether? Online videos of SVB infestations seem to show normal plump green stems that have simply been attacked.

[rainbowgardener]

If the whole plant is pretty shrivelled and wilted, then I would think yes, it's just late stage in the death by borer. If just that area is and the rest of the plant is relatively unaffected (hard to imagine though), maybe something else.


The normal plump stems that have just been attacked is just the beginning of the process...