Artemis:

Your cherry tree was most likely killed by bacterial disease, also known as bacterial canker. It is the most common cause for the demise of cherry trees. The other symptoms you see, ants, termites, etc. are secondary to this problem.

The best way I know of to control or at least delay this disease is dormant spraying with a strong solution of copper. I use a copper hydroxide product called Kocide. If you plant another cherry tree, or any other stone fruit tree, I highly recommend that you do so as well. You should, BTW, tell us your location when asking a question of this nature.

As far as replanting goes, you obviously are not going to plant any new tree over the roots of the old, but I would estimate that if you go about 10 feet out you can avoid most of the old roots. Of course, the farther the better, given your space limits. This disease is present all the time in many locations, but it is airborne not soilborne, so if you follow a good spray routine you should be able to keep new trees healthy.

Before planting any new tree, I would take out the other infected tree as well. These infections can easily spread from tree to tree, and an infected tree does not have much of a future.

Don Yellman, Great Falls, VA

artemis, What Jellyman wrote is good advice. I'd like to add that cherry are very susceptible to root rot and canker. I see you live in sunset zone 17 but you should give your location. Most of the time there are wild sources of disease. Success depends on growing the right ype of fruit tree for your location that you like. On the east coast pears are most resistant to rot rots and cankers. Pears are also most resistant to 'wet feet'. Even the leaves tend to be more insect resistant and I don't have to spray at all generally. Fire blight may be in your area and a Pear may completely die off when it begins to bloom. I am growing the other types of fruit but I am committed to spraying and selecting cultivars adaptable to my climate disease pressures.

You are wise to be concerned. A commercial grower would seldom replant without considerable expense and trouble. Most would fumigate and wait at least a year or two before replanting. But for a home owner there isn't a lot that can be done in this regard other than waiting or planting another species. Choice of rootstock could be significant but not without knowing the problem. Commercially on a replant site they often use a more vigorous rootstock than normal. Soil nematodes contribute to many problems, including bacterial canker, but control requires fumigation.

I'd at least plant something other than cherry, move as far as possible, wait a year or two, and have realistic expectations for a new tree.

The Fruitnut

Thanks all! We're in the SF Bay Area (Oakland, so not in the fog belt---pretty mild/moderate). We do have very heavy clay soil and have been amending it where we've planted new trees to try to mitigate drainage issues after losing two avocado seedlings to root rot.

As far as the second cherry, if this is bacterial canker, is it likely to spread to other fruit trees? We have aging apples, persimmons, and figs (one fig is ill with something too, but our local nursery noted that it may just be at the end of its life). We also have younger plums, avocado, and citrus. All are in close proximity (entire yard is maybe 1200 square feet?).

It's obviously a little late for dormant spraying in our area, but is there anything I should be using in the spring/summer season to prevent the spread of the canker, if it can spread to other nearby trees? It does seem to have been eating away at the cherries for some years now, as the previous owner had taken off large chunks of both trees.

Also, we would like to replace the cherry (though maybe in another part of the yard, it sounds like!) I've seen cherries on both Gisela5 and Mazzard rootstock. (Am guessing the current trees are on Mazzard or something similar as they're huge.) Is one more resilient than the other, or should I just choose based on size/fruiting?

Thanks!

In CA my sources say there is nothing that can be sprayed that will help bacterial canker. I suspect your issues lie primarily with heavy, poor draining soil. So anything you can do to improve that situation will help. Raised beds of a good loam soil would be my first suggestion. A raised bed about 12-18 inches high by 6-8 ft square would be a great help. Some people are having good results with Gisela 5. From what I can tell these are people with good soil, moderate temperatures, and vigorous growth. That rootstock is not working in hot summer areas where the trees are stressed. If you can improve your soil with a raised bed, Gisela 5 would be worth a try. I'm trying Krymsk 5 another precoious, dwarfing cherry rootstock. But it's a crap shoot as K5 is even less tested than G5.

The Fruitnut