My cherry tree has red spots on the leaf stems. Is this normal?, and if not, what should I do to prevent and/or remedy that problem.
Contra Costa Master Gardeners Help Desk Response:
Thank you for calling the Contra Costa Master Gardener Help Desk today regarding the the red spots on your cherry tree leaves.
I was able to confirm that the “red spots” are normal as cherry trees produce a leaf stalk (petiole) that often has 2 or more ‘nectar glands' (your “red spots”). They are known as extrafloral nectaries. These are separate from the flower. If the tree is attacked by pests, these glands exude a special “scent” that attracts beneficial insects that will (hopefully) eat the pest, and so help to protect the tree. It is essentially a natural pest control. The glands are the red “bumps” in the pictures below:
Because you also mentioned that you were interested in the science, please see the scientific details at http://www.botgard.ucla.edu/html/botanytextbooks/lifeforms/antplants/extrafloralnectaries.html.
Enjoy your cherry tree and please contact the Master Gardeners again for any future questions.
Contra Costa Master Gardeners Help Desk
Note: The Contra Costa Master Gardener Help Desk is available year-round to answer your gardening questions. Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA 94523. We can also be reached via telephone: (925) 646-6586, email: firstname.lastname@example.org, or on the web at http://ccmg.ucanr.edu/Ask_Us//span>