This Appeared Today - Ask Extension
I am growing pumpkins and pole beans by the alley in Baltimore City. This appeared overnight. The area has been frequented by rats. The soil is of unk...
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This Appeared Today #909306
Asked July 10, 2025, 4:42 PM EDT
I am growing pumpkins and pole beans by the alley in Baltimore City. This appeared overnight. The area has been frequented by rats. The soil is of unknown characteristics. We are renters. What can I do? Thank you for any information that you can provide.
Baltimore City County Maryland
Expert Response
Hi- these are unusual symptoms. The bright yellow and green leaf coloring can be caused by viruses but the color pattern doesn't fit and you would expect to see the symptom on most or all of the leaves. The dark, irregular spots in the top two photos may be caused by a fungal leaf spot disease.
The white material on the leaf undersides could be from plant cells bursting with excess water (edema) or the build up of dried calcium oxalates pushed out of the leaves due to excess water in the soil and plant. It doesn't look like a disease. athey may want to examine ith with a hand lens or magnifyer to see if any insects are moving around.
General poor growing conditions, such as compacted, low-nutrient soil and less than 8 hours of direct sunlight per day, could have caused some of the symptoms.
Photos of the entire pumpkin plant and garden area could help us give you more guidance. Adding compost to the soil will improve the soil and plant growth.
Rats will burrow and nest in garden soil and feed on veggies. 1/4- in or 1/2-in. hardware cloth ("rat wire") can be used as fencing material to keep them away from food plants. The hardware cloth should at least 3-ft. above ground with at least 6-in. below ground level.
Resources:
UME- Growing pumpkins
Baltimore Rat Rubout program
Brooklyn Botanic Garden – Keep Rats Out of Your Garden
Humane Society – What To Do About Wild Rats
Jon
The white material on the leaf undersides could be from plant cells bursting with excess water (edema) or the build up of dried calcium oxalates pushed out of the leaves due to excess water in the soil and plant. It doesn't look like a disease. athey may want to examine ith with a hand lens or magnifyer to see if any insects are moving around.
General poor growing conditions, such as compacted, low-nutrient soil and less than 8 hours of direct sunlight per day, could have caused some of the symptoms.
Photos of the entire pumpkin plant and garden area could help us give you more guidance. Adding compost to the soil will improve the soil and plant growth.
Rats will burrow and nest in garden soil and feed on veggies. 1/4- in or 1/2-in. hardware cloth ("rat wire") can be used as fencing material to keep them away from food plants. The hardware cloth should at least 3-ft. above ground with at least 6-in. below ground level.
Resources:
UME- Growing pumpkins
Baltimore Rat Rubout program
Brooklyn Botanic Garden – Keep Rats Out of Your Garden
Humane Society – What To Do About Wild Rats
Jon
Thank you for getting back to me so quickly! Here are some more pictures. There are pumpkins growing in the main part. I have pole beans growing along the sides. The leaves shown were the pole bean leaves, not the pumpkin leaves.
It’s already planted out, so I can’t install the rat wire now. Is there a nontoxic spray I can use? Thank you again for your help!
Hi- well, that's embarrassing!
Your plants look healthy. The issues with the pole bean leaves seem to have been temporary and may have been related to environmental conditions. Not a disease or insect pest.
Three repellents to spray on plants and on the ground that may be effective:
Jon
Your plants look healthy. The issues with the pole bean leaves seem to have been temporary and may have been related to environmental conditions. Not a disease or insect pest.
Three repellents to spray on plants and on the ground that may be effective:
- Commercial repellents containing essential oils like rosemary, thyme, mint, and cinnamon
- Homemade sprays made with onion and garlic juice
- Commercial predator urine products
Jon
