Silver Zucchini Leaves - Ask Extension
My zucchini started having this issue where the leaves woul have silver spots starting then eventually the leaves all around the veins and then the ve...
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Silver Zucchini Leaves #800040
Asked July 08, 2022, 11:31 AM EDT
My zucchini started having this issue where the leaves woul have silver spots starting then eventually the leaves all around the veins and then the veins would turn silver. This is laso happening to my butternut squash. Definitely not powdery mildew. It's more of a problem with my outdoor zucchin than the two plants in my green house. It's also no affecting every leaf on the plant pest?,Mineral deficiency?,blight?
Sanilac County Michigan
Expert Response
Thank you, Richard, for your question!
As zucchini plants mature, the oldest leaves often develop silver or grey blotches, streaks and spots on their upper surfaces. In this case, there is no disease or pest present, it is simply one sign of a mature leaf. As long as the silver areas are not accompanied by insects feeding on the underside, blooming fungal bodies, or dried out spots along the leaf's surface, it's unlikely that your zucchini is ill.
This article Diseases and Insects in Michigan Cucurbits and their Management (E3276) - MSU Extension outlines all the diseases and pests that can attack the cucurbit family of plants, which includes zucchini and squash. Another good one with lots of pictures is Virus Diseases of Cucurbits (cornell.edu)
Your plant looks healthy. Continue to practice good watering choices such as a drip or soaker type. I might suggest placing some mulch (any barrier of your choice, newspaper, cardboard, wood chips, etc.) down to alleviate soil splashing onto your plants. A general type of garden fertilizer may be used as zucchini tend to be heavy feeders.
May your harvest be bountiful!
As zucchini plants mature, the oldest leaves often develop silver or grey blotches, streaks and spots on their upper surfaces. In this case, there is no disease or pest present, it is simply one sign of a mature leaf. As long as the silver areas are not accompanied by insects feeding on the underside, blooming fungal bodies, or dried out spots along the leaf's surface, it's unlikely that your zucchini is ill.
This article Diseases and Insects in Michigan Cucurbits and their Management (E3276) - MSU Extension outlines all the diseases and pests that can attack the cucurbit family of plants, which includes zucchini and squash. Another good one with lots of pictures is Virus Diseases of Cucurbits (cornell.edu)
Your plant looks healthy. Continue to practice good watering choices such as a drip or soaker type. I might suggest placing some mulch (any barrier of your choice, newspaper, cardboard, wood chips, etc.) down to alleviate soil splashing onto your plants. A general type of garden fertilizer may be used as zucchini tend to be heavy feeders.
May your harvest be bountiful!
Thank you for the information, I never knew that. Does this apply to other squash also as this is happening to my butternut but nothing else.
The Extension Specialist states in this article that yes it may apply to other plants in the cucurbit family of plants.
White blotches on zucchini leaves may be normal or may be fungus (nmsu.edu)
Thank you, Richard, for your question!
White blotches on zucchini leaves may be normal or may be fungus (nmsu.edu)
Thank you, Richard, for your question!
