Crab apple scab management (zone 7a, Fairfield County, CT)

HU-918119203

3 years ago

last modified: 3 years ago

I have two mature crabapples that provide valuable screening and shade for a patio area. They've dealt with what I believe is apple scab each of the three years I've lived here. This year, it seems worse than ever, with the trees dropping a significant amount of leaves already, something that in prior years has not happened until mid or late summer.

Based on my prior research, I try to spray the trees several times in the early leaf-tip and budding stages. I say "try" because it really is difficult - it's cold enough here (Fairfield County, CT, zone 7a) in early March that we're at risk of a hard freeze, so I am reluctant to turn on my outside water. It rains frequently, which prevents spraying on those days. And, um, I also have a busy schedule that does not revolve entirely around tree spraying.

This year, I sprayed at least twice, maybe three times, during the appropriate times. Yet the scab seems worse than ever. I was really surprised, because the trees abundantly bloomed and fruited more than I'd seen in prior years.

What else, if anything, can I do to help these trees? They are in drip-irrigated beds that get annual applications of organic mulch and compost.

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Comments (4)

ken_adrian Adrian MI cold Z5
3 years ago
find some crabs that are resistant ..and plant them now.. so in a few years.. you can get rid of these ...

ken
HU-918119203
Original Author
3 years ago
That's not very encouraging!
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gardengal48 (PNW Z8/9)
3 years ago
TBH, ken's advice makes a great deal of sense. If you are already spraying with a registered fungicide at the suggested times, there really isn't anything else you can do to control the scab. You can't determine weather conditions and weather has a lot to do with how scab develops and is spread.

Other than the spraying and good garden sanitation in removing and destroying all fallen leaves, then replacing the crabs with disease resistant cultivars is the only remaining alternative.
HU-918119203
Original Author
3 years ago
last modified: 3 years ago
Well, that is depressing. But if that's the best I can do, it's the best I can do.

Suggestions for zone 7a/Farfield County, CT? Don't need to be crabapples - in fact, may be better if they are not because scab aside, the dropped fruit and spent flowers can be a pain too (I have another crab in the yard which is doing better, so spring flowering tree is covered).

A tree that will not get very tall but is wide enough to provide nice screening, will ideally leaf out fairly early and hold leaves fairly late, with roots that will play nice with boxwood and other perennials, will provide dappled, bright shade sufficient to sustain other plantings in the patio, and is relatively disease and pest resistant? I have already lost a white bitch to borer, so not interested in that.

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