Black Knot on Ornamentals

We’re seeing Black Knot pop up all over Long Island — especially on plum and cherry trees. This fungal disease is easy to spot: look for hard, black, swollen galls on branches that look like burnt clumps of charcoal.

While it won’t kill the tree overnight, Black Knot stresses trees, reduces vigor, and spreads easily if left untreated.

What to do:

* The best time to prune out infected branches is late winter, before bud break, when the fungus is dormant and less likely to spread.

* Always remove and discard infected wood — don’t compost it!

Support the tree’s recovery

To help infected trees bounce back, we use compost tea fertilization to strengthen roots, improve soil biology, and boost resilience organically.

Need help with tree care? We’ve got you covered — organically.