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Plant Diseases/japanese maple


have a 4 ft tall maple that is potted.  recently have noted a sudden browning &
"crisping" of the leaves over the entire tree. there has been no obvious changes in the care/environment of the tree,the bark shows no break, etc. i need to know if the malethion mosquito spray that i sprayed in area is the likely culprit?

Dear Liv, I can definitely assure you that the reason for your browning of your Japanese maple is NOT the malathion.  The only plants that malathion really bothers is ferns.  The only way this could have been a problem is if you sprayed a concentrated dosage at the tree in bright sunlight which could cause a condition known as phytotoxicity. If you did, the tree should be fine after leaf fall.  In fact, I do know what is probably wrong with your maple.  I see it every year, every August, in almost every Japanese maple I have ever seen.  It is mostly lack of water, extreme heat, and well, it's August and it's really hot out there, even if you do live further north, and you have the plant in an optimum area.  Plus the leaves are getting older, and are bound to be more worn out and susceptible to damage than they were when they are newer.  Try watering your tree a bit more, and then don't worry.  The leaves will be falling soon, and the tree never seems to suffer as a result.  Just try to keep these maples watered well, be aware that this type of damage may occur in July-Aug-Sept and add more water at this time.  I hope this information helps, let me know if I may be of further assistance.  Good luck, Melissa

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Melissa Johnston


Plant diseases, landscaping, tropical plants, roses, herbs, plant care, grafting, horticulture, plant identification, anything about plants I can likely answer.


35 years experience in various plant businesses, 1984 Certified Texas Master Gardener.

Master Gardener Association of Texas charter member

none as of yet, but I have a plant q&a book I am in process of submitting.

Magna cum laude graduate of Texas A&M, 1978

Awards and Honors
Plant growing awards, highest grade for Texas Master Gardener graduates.

Past/Present Clients
Past member of and was very highly rated. Owned landscape company in the past, Almost Paradise, and was very successful despite little equipment, no help, and no advertising. Lived well for two years until 9/11.

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