What do I do about peach leaf curl?
Peach leaf curl is caused by a fungus that infects young leaves just after the buds break in early spring, causing them to pucker, twist and form colourful red blisters. It's a difficult disease to control without placing your trees on a spray program, but that doesn't mean many haven't tried.
One recommended method for controlling the fungus is to limit the amount of moisture that can come in contact with the plant's leaves, particularly in the early spring when those leaves are first forming. This means erecting a waterproof structure over the plant for several weeks each spring then taking it down once the wet, cool conditions pass.
Another control is to pick off infected leaf clusters as soon as you notice any abnormalities and dispose of them along with any dead twigs you prune from the tree. Disposing of them means placing them in a garbage bag and removing them from your property. Do not compost diseased plant material or leave it lying around your property. Doing so only guarantees the fungus will strike again next season.
As much as I hate spray programs, you likely won't be able to control peach leaf curl without one. Bordeaux mixture, lime sulphur or copper sprays applied during the dormant season have proven effective. Contact your local garden centre for details on how to appropriately employ these controls. Of course, if your trees are too large to spray yourself – or you don't want to mess around with the sprays - you'll need to bring in a commercial sprayer to do the job for you.
Peach leaf curl isn't the sort of problem that just goes away on its own and often, as the disease advances, the leaves which at first were discoloured and distorted eventually turn grey and fall off. A peach tree that defoliates year after year will go into decline and, as it does so, will become susceptible to all sorts of secondary infestations. For that reason, it's a good idea to either manage the problem or cut the tree down and plant a cultivar less susceptible to peach leaf curl, such as 'Pacific Gold' or 'Renton'.
Nectarines are equally susceptible to peach leaf curl and the controls are the same for both species.
If you have any questions or comments, please send them to me at vanessa@gardenmuse.ca.
