Gall on ornamental plum

Hi all. I'm still new here, and am sort of tree challanged. A few years back I had an ornamental plum...about 10 yrs. old.It developed black wart-like nodules on the branches. The branch would die. I'd cut it off and dispose it. This went on for years. Then over one winter the whole tree died. I did have several tree experts look at it. They said it was Black Gall and that the tree would die. OK I also have a weeping Japanese cherry tree. I am worried that it will get this too. This cherry has an exfoliated bark. (the bark peels). It's app. 10 yrs. old. It's a beauty. I would be heart-broken if it died from this disease. Can anyone advise me? Thank you in advance. Also, it has split in the trunk right where the canopy starts. I'm worried about that too.

I believe you can prune out black knot galls successfully as long as you take out the whole branch a couple of feet proximal to the swelling so as not to leave anything to reinfect. At least it's worked for me in the past. Maybe someone else has better info?

Guy S.

Spraying twice with dormant oil spray during the winter has seemed to help mine the last few years.

You should seriously consider cutting off all of the branches infected with black knot right now and burn them or bag them and toss them out with your regular garbage. You will want to make your cuts at least 6" below the knot. Should you choose to go this route, dip and soak your tools in a mild dillution of bleach before you cut another limb. Spraying with Lysol between cuts can also be effective. It would appear Apiosporina morbosa (the fungus responsible for Black Knot) is in your area. You are going to have to consider getting out there this coming fall and again in late witner before spring to prune any branches. These are the best times to prune for Black Knot because fall and particularly spring are nice times of year for the fungus to reproduce for the following reasons-

Sorry for cutting and pasting that but it was much easier than locating a previous post I made.

I do not believe dormant oils are effective. Perhaps as a prophylactic to an otherwise healthy plant?

You might want to consider watching how you water this plant. Try to water only in the mornings and don't over water.

Also too, if you plant any more plums, please consider a black knot resistant variety.

It may be in my imagination then LOL. The old plum trees that were here were so badly infected that I just cut the whole trees down. I haven't noticed it on any of my younger ones yet. I did burn the old trees.

This message was edited Jun 15, 2006 10:37 AM

I dealt with this for a few years and finally gave up pruning in favor of removing the trees and planting back black knot resistant species. The trees were growing and when they were small it wasn't so difficult reaching up to remove diseased limbs but as they grew I found myself on a ladder that wasn't all that stable in the grass stretching to prune out diseased limbs and figured I'd about had enough. No sense doing a face plant in my lawn falling off a ladder trying to prune out a limb that was way out of my reach.

I think that's about the only thing you haven't already done to yourself with your garden mishaps -- why not go for the clean sweep?

Guy S.

Nope, I've done face plants here. I've come up out of the mud in the wetlands looking like a Mud Monster from a B rated horror flick. I've been so encased in mucky mud that I couldn't hardly see out of my eyes until I got to the house and hosed my face off. Sort of funny the mud I left along the side of the house feeling my way to where I knew the spigot was. I think the ladder deal was just too risky being as how I didn't like the way it was wobbling when I was up there.

Thank you Equilibrium. I know there are a lot of nasty plant diseases but this one was particularly gruesome. I forgot to mention...the whole tree died over the winter and I took it down. I couldn't burn it because I live in the city and the Fire Dep't gets a little testy about those things. I did, however, dispose of it. I'm really concerned about my weeping cherry, though. I dont know what kind it is and have not seen another one like it. It has a shiny mahagony colored bark that peals. Great looking in the winter.

I think I'll stay away from Plums. That tree just about did me in.

Thanks again

Try a Santa Rosa Plum or a President. Nice spring blooms and although they are fruiting trees, they both have ornamental value in my opinion.