You're so happy to see your squash are growing green, healthy and lush. But one day, you noticed that your squash leaves are turning yellow, it starts from one leaf, but finally all leaves in a vine are becoming yellow. I know you worry the squash, but let's figure out the reason of turning yellow, it's normal or bad? how to fix it right?
The Reasons of Turning Yellow and How to Fix
I list several reasons and propose corresponding solutions, hope you who may meet the same problem can clear it out.
Squash is very hardy, but needs about 1-2 inch water every week. Sometime, it need more in hot summer. If you plant squash in grow bags, water frequently. Check your squashes if they can get enough water, if not, you can use drip irrigation system to provide your plants water.
Vine Borer will attack your pumpkin and go through cines. The most obvious phenomenon is that leaves are turning yellow, from the base end of a vine to the tip. and a small pile of "sawdust" in the base of the vine, where it come out from the ground. If the reason is the Vine Borer, then the pesticide is useless, the only effective solution, not always success, is to get rid of the vine borer from the vine. Go to the vine you suspected that it has vine borer, slit the vine vertically (follow capillaries). It won't hurt your squash plants too much, but if you cannot find the vine borer, your squash is doomed to die. If you can find it, use toothpicks to pierce and kill it.
Lack of Iron
Iron is the nutrition which makes leaves green. Without iron, plants are difficult to generate chlorophyll. Adding iron chelate (a kind of compost) into the soil would be helpful. In most situation, iron deficiency is the result of over watering, so nutrition flow out of soil. Check if you over-water your squash.
If you squash is infected by wilt, sadly, you have no way to save it, squash leaves will gradually become yellow and wither, and die finally. Bacterial wilt can be diagnosed by cutting off a piece of the stem and squeezing out some of the juice inside. If the juice comes out slimy or oozing, then the plant has been infected. Destroy the plants and don’t compost them. Don’t plant squash or other cucurbit vines in that location next year, as the bacterial wilt will still be in the soil and will infect them as well.
Although the conditions listed above are some of the most common reasons for pumpkins to grow yellow leaves, they are not the only reason. As mentioned above, the leaves of pumpkin plants turn yellow when the plant is stressed. If you can find out what is putting stress on the plant, then you can correct the situation and help your pumpkin restore its green color.