Apple scab is prevented from returning by removing fallen leaves each fall, since that's where the fungus spends winter, combined with a preventive fungicide spray applied before symptoms appear the following spring.

Why Does Fall Leaf Cleanup Prevent Next Year's Infection?

The apple scab fungus overwinters in fallen leaves left on the ground beneath the tree, releasing spores the following spring that reinfect new leaves as they emerge. Raking up and destroying those fallen leaves each fall removes the fungus's overwintering site before it gets the chance to complete that cycle.

When Should Preventive Fungicide Be Applied in Spring?

Preventive spraying should begin as soon as leaves emerge in spring, before scab symptoms are visible, then repeat once the leaves are fully developed and again as fruit begins to form. Applying Liquid Copper Fungicide Spray onto the foliage at this stage protects new growth before the fungus has a chance to establish, rather than treating symptoms that have already appeared.

Is There an Alternative for Trees Too Tall to Spray?

Trees too tall to spray effectively can be treated at the trunk instead. Garden Phos with Pentra Bark, applied directly to the trunk, offers a non-spraying option for preventing scab and several related diseases on trees where full-canopy spraying isn't practical.

Frequently Asked Questions

How much does preventive apple scab treatment cost?

$18.95 to $44.95, depending on which method is used. Liquid Copper Fungicide Spray costs $18.95 for one pint, and Garden Phos with Pentra Bark costs $44.95 for the combo trunk-application package.

Does fall cleanup help even if neighboring trees aren't cleaned up too?

Yes, but its effectiveness is reduced. Wind can carry fungal spores in from a neighboring, uncleaned tree's fallen leaves, so cleanup works best when nearby apple or crabapple trees are treated the same way, though it still reduces the spore load from the tree's own leaf litter regardless.

Can fall cleanup alone prevent scab without spring spraying?

Not entirely on its own. Fall cleanup reduces the fungus's main overwintering source, but spores can still travel in from other infected trees nearby, so pairing cleanup with a spring preventive spray gives more reliable protection than either step alone.

Does removing fallen leaves help prevent other diseases too?

Yes. Removing fallen leaves also reduces the overwintering source for several other fungal leaf diseases, since many fungi that infect leaves spend winter in the same fallen leaf litter beneath a tree.