Plum tree care

[ecostar]

Hello,

I have a plum tree (species unknown) which was transplanted into my school garden last spring, in a sunny location next to some apple trees. I recently checked on it and it has a alot of sap oozing from multiple "sores" on the trunk. I don't know what it is, or what I could do about it. My first thought was that it could be sunburn, but I'm not sure...

Any suggestions?

Thanks!

[Newt]

Hi Ecostar,

I suspect your plum tree has scales.* They are an insect pest. The sap you see is actually their waste that is called honeydew.* Ants and bees harvest the sweet honeydew and will defend the scales from predators.* Eventually the honeydew grows a black mold called sooty mold.* Is this what you see?

http://treegrowersdiary.com/imagelib...et=tlx_pic9u51


If so, you can use either a horticultural oil or insecticidal soap.* Both would be safe aruond children. I would suggest an horticultural oil called Organocide made from sesame seeds.* Most horticultural oils are made from petroleum.* The best time to spray the oil is in May.* In the meantime you can make your own insecticidal soap.* Be sure to use soap and not detergent as that can harm the leaves.* Spray every 5 to 7 days until they die off and spray early in the day before bees or other beneficial insects become active.
http://www.care2.com/greenliving/hom...idal-soap.html

You can see more pics of these pests here, the site I got the picture from.
http://treegrowersdiary.com/purpleleafplum.html

Newt