I have two plum trees in my front yard. I cut down one branch that was hanging down to low, getting in the way, and found it was covered with aphids!
I have no idea what to do....how do you spray a tallish....15 foot to the top, tree? I don't even want to check the other tree (too yucky), about 15 feet away, to see if it is infected?
What should I do?
Can you tell whether you have either of these kinds of aphids?
How much damage is there to the branches and the tree? Are the leaves damaged as shown in the photo in the link above?
Here's a good photo of a mealy plum aphid: http://www.ipm.ucdavis.edu/PMG/r611301711.html
Here are some good noninsecticide alternatives: http://forums.gardenweb.com/fo...sg0523101816168.html
http://www.botanicalgarden.ubc...owthread.php?t=27452. This link includes some personal first hand experience on the use of soaps as insecticides and self protection while spraying.
You'll probably have to get one of the pump sprayers (they look like fire extinguishers) to spray. If you're comfortable on an ladder, use it, but if you've got uneven ground, stabilize the ladder and have someone standing by. Wear a mask just in case there's some blowback onto you.
And another on first hand experience: http://forums2.gardenweb.com/f...sg0519081214647.html.
Read the 4th and 5th posts for the best information, especially the comment on use of high nitrogen fertilizer. Farther down there are some interesting comments on the use of coffee grounds to deter aphids. The poster "Kimmsr" has posted on a number of gardening forums I've visited over the years and almost always offers good advice. If I remember correctly, he works in some kind of gardening professional position, maybe with the DNR, but I don't recall specifically.
If you want more information, Google "plum trees, aphids" - I got a lot of hits.
It's my understanding that ants "farm" aphids for the sugary secretions they exude. This is an interesting article on that symbiotic relationship. You might want to see if you have ants on your plum tree as well. If not, I would expect them soon.
The site above offers more insight on the relationship between ants and aphids. Ladybugs apparently also like aphids. Some garden supply catalogues sell dormant ladybugs, which you can allow to hatch and then sic them on the aphids.
My aunt and uncle had an alpine garden with rare and unusual plants which they sold. They bought aphids, let them hatch and turned them loose in the garden.
Have you experienced a drought in your area in the last year? As one of the comments I read somewhere suggests, you'll also need to determine why there are so many ants, what conditions allowed them to flourish, so that your attack is on two levels: elimination, and addressing the underlying conditions which attracted them in the first place.
From my experience, I found that plum trees were susceptible to disease, and after several years just cut them down as they were producing more undesirable pests than fruit.
WOW is all I can say. You really covered it all. Thanks so much. Looks like I have a lot of reading/homework to do.
One further thought on how to safely spray the trees. If you have a two story home, you can spray from one of the second story windows. It would be safer than spraying while on a ladder.
You may want to try a trombone sprayer to get to the tree tops here's one place to get them http://www.northerntool.com/sh..._200279574_200279574
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