| Maurice |
Sainte-Catherine-de-Hatley, Quebec, Canada
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I’m seeing a recurring problem with my pumpkins and can’t identify the cause.
The symptoms start on the oldest leaves. The leaf margins turn yellow and the yellowing progresses inward. As it approaches the center, the outer edge turns brown and the browning also progresses inward. Just before the brown reaches the center, the leaf curls up, then collapses completely. The problem then moves progressively from older leaves to newer leaves.
I have two raised beds, each about 30 sq ft and 10 inches deep, with clay/gravel subsoil underneath. They are 25 feet from trees, 6 feet from a road, and receive about 7 hours of sun daily.
Everything else grows well there, including peppers, lettuce, carrots, tomatoes, zucchini, and cucumbers. However, pumpkins consistently decline this way. Last year I lost a giant pumpkin plant; this year field pumpkins are showing the same symptoms.
The new growth always appears healthy and green. The decline slowly progresses down the main vine and eventually affects the secondaries. The secondaries die in a similar manner, although they often do not show the same yellowing beforehand. Secondary growth eventually stops.
Another observation is that the main vine never seems to exceed about 2 cm in diameter. Fruit set is poor and fruits grow very slowly. Last year I also had several unusual flowers with about 10 lobes.
I amend the beds annually with about 60 L of compost. Last year, the vine near the stump became hollow, with brown, cracked outer tissue, yet the plant continued growing about 16 inches per week through October. It never grew faster than that, even during peak summer growth.
One additional detail: last year there was a heat wave with daytime temperatures of 33–38°C and nighttime temperatures of 16–19°C. I watered regularly throughout that period.
Does this sound familiar to anyone?
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6/8/2026 4:19:54 PM
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