Crabapple trees are mid-sized trees with green leaves and bright, small fruits that are tart to eat straight but delicious in a homemade jam or pie. A crabapple tree or several can turn any backyard into a garden without all the effort associated with apple trees or ground plantings. But it is important to perform regular checks and maintenance on your crabapple trees to keep the trees free of disease.
There are a few different diseases that strike crabapple trees, and knowing the signs can help you prevent further damage down the line.
Powdery mildew is easy to spot due to the white-gray mildew-like film that appears on the surface of the crabapple tree's leaves and fruit. The film buildup can block out the photosynthesis cells in the leaves and cause the leaves to prematurely, and perhaps permanently, wither and die.
The good news is that powdery mildew is largely an appearance problem that won't damage the trunk or bark of the tree. If only a few leaves or fruit are presenting with the film, remove the affected pieces and then apply a fungicide recommended for powdery mildew treatment.
Apple Scab Disease
Apple scab disease can affect either crabapple or regular apple trees. The scab will initially present as greenish brown welts on the branches, leaves, or fruit. The welts might have a soft-looking texture. As the disease progresses, the welts will blacken and leaves will start to turn yellow, then brown, and fall off prematurely.
Treatment for an already affected tree is limited to calling in a tree trimming company, such as Treetime Inc, to remove any pieces that are already showing symptoms. You might then apply a fungicide to prevent the disease from returning. But if the tree is already largely infected, a tree removal service will need to cut the tree down to save your other trees.
Fire blight is a somewhat rare but potentially fatal disease that can strike crabapple trees. The blight can present in several different symptoms but most indicate that a rotting is taking place. For example, leaves and fruit emerging for the season can come out underdeveloped and turn brown or black quickly and then fall off.
Treat fire blight as it presents by quickly trimming off any affected branches. If the disease continues to spread, you will need to have the tree removed.
Prevent fire blight from occurring in the first place by maintaining regular pruning practices and regularly applying fungicide to your crabapple trees.