Squash leaves - Ask Extension
I garden organically in the central Willamette Valley. My young squash (both winter and summer) have yellow leaf margins.The only thing I can find sug...
Knowledgebase
Squash leaves #874311
Asked June 23, 2024, 3:54 PM EDT
I garden organically in the central Willamette Valley. My young squash (both winter and summer) have yellow leaf margins.The only thing I can find suggests they may be overwatered. Can it be anything else? All plants are afflicted.
Linn County Oregon
Expert Response
Dear KPMiller,
You plants may have nutrient deficiencies. It could be watering, or pests and/or disease. Pictures would help in IDing the issues.
Potassium deficiency causes bright yellow leaf margins. The rest of the leaf is green to start off with.
Nitrogen deficiency is a general yellowing of the leaves starting with the bottom leaves or the oldest leaves and then working their way up the plant.
Iron deficiency could be another problem.
Are the leaves limp and yellow, is the soil soggy wet? Let it dry out. During hot weather you may need to water more because underwatering may cause the leaves to yellow as well.
However, with all that said, you probably need more nutrients in the soil.
Purchase some fish emulsion, follow the directions on the bottle and start using it regularly to see if the plants start to grow and new leaves are all green. It will not change the edges.
Also, put a manure compost around the plants. Squash plants are heavy feeders and need a lot of nitrogen. Water it in if the soil is not soggy.
If you stick your finger into the soil about 2 inches and the soil is soggy, do not water for a few days, and recheck. If it is just moist, you can water on a regular basis, again depending on the weather. Warmer weather and wind will require more water.
Overwatering can cause nutrients to be leached out of the soil. I am attaching a link on squash leaves and why they may be turning yellow.
https://www.thespruce.com/squash-leaves-turning-yellow-7965917
If you have further questions, please contact us again.
You plants may have nutrient deficiencies. It could be watering, or pests and/or disease. Pictures would help in IDing the issues.
Potassium deficiency causes bright yellow leaf margins. The rest of the leaf is green to start off with.
Nitrogen deficiency is a general yellowing of the leaves starting with the bottom leaves or the oldest leaves and then working their way up the plant.
Iron deficiency could be another problem.
Are the leaves limp and yellow, is the soil soggy wet? Let it dry out. During hot weather you may need to water more because underwatering may cause the leaves to yellow as well.
However, with all that said, you probably need more nutrients in the soil.
Purchase some fish emulsion, follow the directions on the bottle and start using it regularly to see if the plants start to grow and new leaves are all green. It will not change the edges.
Also, put a manure compost around the plants. Squash plants are heavy feeders and need a lot of nitrogen. Water it in if the soil is not soggy.
If you stick your finger into the soil about 2 inches and the soil is soggy, do not water for a few days, and recheck. If it is just moist, you can water on a regular basis, again depending on the weather. Warmer weather and wind will require more water.
Overwatering can cause nutrients to be leached out of the soil. I am attaching a link on squash leaves and why they may be turning yellow.
https://www.thespruce.com/squash-leaves-turning-yellow-7965917
If you have further questions, please contact us again.
