yellow squash leaves

annastasia76 · Fri Jun 03, 2011 1:35 pm

what causes the leaves of a zucchini plant to turn bright yellow, the entire leaf??

I wanted to remove the plant when it started turning yellow but hubby insisted it was nothing and to leave it. so I left it until the entire leaf turned yellow then all the rest turned yellow (oh and I should mention that these are full size leaves about 7-10" across) so one day while hubby was gone I yanked the plant out, he was upset but oh well, I didn't want it to spread, well now even though the other plants never got within even 2 feet of each other, another plant is starting to get yellow leaves, I don't want to pull this one, it is one of the only 2 that I have planted with the yellow squash that survived the late frost.

I should also mention that there was no browning or other signs of disease, just bright yellow leaves

jal_ut · Fri Jun 03, 2011 9:45 pm

Something is stressing your plants. Are they getting enough water?
Any signs of vine borers?

A severe iron deficiency could cause that problem.

annastasia76 · Sat Jun 04, 2011 1:52 am

I'm thinking maybe an iron deficiency, hoping at least, I have never seen squash vine borers on my plants before but there could be a first time, what do I need to look for before I cut into the plant??

cynthia_h · Sat Jun 04, 2011 2:15 am

I don't believe squash vine borers are found west of the Rockies (or maybe it's the Sierra). You can check up on me, but this is one evil creature that we're spared in California. So far.

Cynthia H.
Sunset Zone 17, USDA Zone 9

rainbowgardener · Sat Jun 04, 2011 7:01 am

Jal_UT is right (as always!) that it is a sign of stress in the plant. Could be under watering or over watering. If an iron deficiency, most often the plants would be chlorotic, that is would still have some green around the veins, leading to a tracery effect. Over watering can cause iron deficiency because it leaches nutrients and minerals out of the soil. Nitrogen deficiency could also cause yellowing leaves. If it were me, since I don't use synthetic fertilizers, I would mix some compost in to the soil around them. Otherwise you could use a good balanced and complete fertilizer, with trace nutrients.

annastasia76 · Sat Jun 04, 2011 9:47 am

It may be from over watering, I have been trying to be careful on the watering but then hubby turns it on for whatever reason without me knowing about it and leaves it on, I'll see if I can let it go a few days without water, I'll also try and see if I can get some iron to it. I have been giving the plants fish fertilizer about every 3-4 weeks, it's hard for me to judge exactly how much to give them because it goes by square feet and I don't water the entire area, just at the plant, so if anything I have been hopefully under fertilizing to prevent from burning the roots.

sheeshshe · Sat Jun 04, 2011 12:40 pm

I[m having the same problem but mine are little tiny plants. Trying to figure out the over or under watering thing. Hopefully I can get them looking green!

jal_ut · Sat Jun 04, 2011 9:07 pm

Vine borers, rare in Utah. I have seen them a few times. They are apparently not able to over winter here in this cold climate. So if we get them, they have to move in from down south and its a long way to travel. They just don't make it here very often. Thankfully.

The times I have seen them, I had no idea until one day a plant was flat on the ground. It just wilts and falls down. Once you get to looking, you can see the little holes where they bored into the stem and stuff that looks like sawdust around the area. I have never tried to save such a plant. It goes into the compost heap.