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Ask The Yard Doctor Dahlias

Marks on Leaves

2 years ago

I'm experiencing light yellow marks on the leaves in my garden, on everything from dahlias to corn to nasturtiums. Is this some kind of insect doing damage to the leaf surface, or a virus perhaps? It ranges from barely noticable to quite severe, as shown in the photo below. Is this a threat to the health of the plant?

Comments (5)

scottie mom
2 years ago
I've got the same thing, only on the dahlias. It's my first time growing them. I bought tubers from two specialty farms. One batch has barely grown at all. I think I've got one out of eight that grew at all. The other batch has grown, but most of the leaves look like your photos above. I'm in Central Virginia. Zone 7B.

Grateful for any advice :-)
raymondo17
Original Author
2 years ago
After additional research, it appears I have spider mites throughout my garden. I’m trying an alternating schedule of Neem Oil and Captain Jack’s Dead Bug Brew. I think it’s important to try and catch this as early as possible.

Good luck with your Dahlias!
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scottie mom
2 years ago
Interesting--I'm thinking I have those or leafhoppers. I have the Captain Jacks and will try that tonight. I've used it twice. I wonder if insecticidal soap will help. I did try epson salt (1tb in a gallon of water) as recommended by the dahlia farmer who sold me some of the tubers. She said the plants near her house looked like this, but that her field was fine. Thank you for the help and good luck to you!!
raymondo17
Original Author
2 years ago
Insecticidal soap is a good first line of defense. If you only have a few plants with minimal signs of distress, go with the soap. You might even try spraying them off your plants with a hard stream of water. But if yours are anything like mine, it’s time to break out the bigger guns.
scottie mom
2 years ago
I just went out there again (in the blazing heat,) and removed some of the lower leaves. Gave the leaves a bit of a bath, and I'll go back with the Captain Jack's after the wind dies down and the pollinators go to bed. I really appreciate your advice. Thank you! Let me know how it goes with the Neem. I may pick up some of that later this week.

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