Yellow on summer squash leaves

rmonge00

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I have some healthy looking summer squash, but some of the leaves are turning yellow. They still look firm and healthy, but the yellow color is concerning. Does anyone know what this is?

Thanks!

Ryan
 

lesa

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Is it the bottom leaves that are affected? I would pull the yellow leaves off, and dispose of them- but I don't think it is anything to worry about.
 

catjac1975

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I planted out my squash as seedlings rather than direct sown. Mine were quite yellow after planting. I used a liquid organic fertilizer and they greened up and took off very quickly. Seedlings suffer a little shock no matter how carefully you plant them. Also in Massachusetts, we have soil that is a bit acidic sfof limestone is necessary for squash and other crops.
 

AllyRodrigues

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If it isn't just the bottom leaves turning yellow, but some of your stronger ones, this was the first sign of squash bugs for me. Maybe water the plant and inspect closely?
 

JimWWhite

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I have to agree with Ally R. above in that you have squash bugs. I lose my squash plants almost every year to them. They bore into the base of the plants and suck the life out of them and that's what you see when the leaves start turning yellow. I can't spray anything because of our bees so the only thing left is to manually kill them. One thing that does work is a trick you have to do on a regular basis. Water your plants heavily with a sprinkler in the late afternoon just at dusk. The squash bugs hate it when you water and they come out into the open. Kill as many as you can at that time. I use a long rubber band and pop 'em off the leaves. With a little practice you can get them and not tear the leaf. Then before you go in for the night take a short plank or a piece of wood about 8"x1' or so and lay it down near the base of the plant. Put a few pebbles under the corners to lift it up a bit. Then in the morning go out when it's still cool, lift up the plank and stomp the &*$#% out of them. They love to hide under things like that. Crude, but effective if you don't want to or can't spray Sevin or something like that. Oh, and look for orange egg masses on the underside of the leaves and smash them. That being said, I still lose my plants to them.
 

so lucky

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Jim, could you put some insecticide on the ground under the plants? I'm sure you have thought of that; maybe there's not a good insecticide for that purpose anymore.
 

JimWWhite

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so lucky said:
Jim, could you put some insecticide on the ground under the plants? I'm sure you have thought of that; maybe there's not a good insecticide for that purpose anymore.
Yes, I think you could use Sevin dust but like I said because we keep bees I'd had to take the chance of killing a colony with that stuff. Besides I have earthworms in the raised beds and that'd do them in too. It's just something you have to live with and work hard to keep them off if you want squash. Cucumbers too.
 

ninnymary

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Could it be too much water? I know over here, we don't have squash bugs, so maybe you don't either, depending on where you are.

Mary
 

catjac1975

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Jim- What you are describing is the squash vine borer. If you put BT in the hole when you first see it it will kill the borer and sometimes saves the plant. Squash bugs also kill your plants and can be controlled with pyrethrum or bulls' eye, both organic products. It only works on the nymphs. Successive plants also work. Once the first crop is destroyed the second crop will be coming along. I have also reduced my squash bug population overall by allowing my chickens to range in the garden on the off season. At least I think this is the reason for the overall reduction in squash bug population.
JimWWhite said:
I have to agree with Ally R. above in that you have squash bugs. I lose my squash plants almost every year to them. They bore into the base of the plants and suck the life out of them and that's what you see when the leaves start turning yellow. I can't spray anything because of our bees so the only thing left is to manually kill them. One thing that does work is a trick you have to do on a regular basis. Water your plants heavily with a sprinkler in the late afternoon just at dusk. The squash bugs hate it when you water and they come out into the open. Kill as many as you can at that time. I use a long rubber band and pop 'em off the leaves. With a little practice you can get them and not tear the leaf. Then before you go in for the night take a short plank or a piece of wood about 8"x1' or so and lay it down near the base of the plant. Put a few pebbles under the corners to lift it up a bit. Then in the morning go out when it's still cool, lift up the plank and stomp the &*$#% out of them. They love to hide under things like that. Crude, but effective if you don't want to or can't spray Sevin or something like that. Oh, and look for orange egg masses on the underside of the leaves and smash them. That being said, I still lose my plants to them.
 

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