How to Cure Fungal Leaf Spots on a Ligustrum Tree

Cultural Management

• 1

  Trim off any leaves or twigs showing fungal leaf spot symptoms, cutting them back to the nearest leaf or bud on healthy wood. Wipe the shears with a cloth soaked in isopropyl alcohol after each cut. Prune off all infected foliage in fall and winter. Continue to prune lightly during the growing season, if necessary. Privets tolerate pruning at any time.

• 2

  Remove all fallen foliage and plant debris from beneath the privet bushes. Regular foliage cleanup prevents the fungal spores from breeding in the dead plant material and spreading back to the healthy foliage.

• 3

  Water the privet in the morning after any fallen leaves are removed, otherwise watering may splash fungal spores back onto the plant. Early morning watering ensures any moisture on the foliage dries quickly. Avoid overhead watering that results in wet foliage, because leaf spot fungus grows most readily on wet plants.

Fungicide Application

• 4

  Attach a hose-end sprayer to the garden hose. Adjust the delivery amount on the sprayer to 2 1/2 tablespoons for every 1 gallon of water. Application amounts may vary between fungicide brands, so verify the settings on the product label before use.

• 5

  Fill the sprayer reservoir to the fill line with a fungicide containing the active ingredient chlorothalonil. Chlorothalonil helps prevent the spread of both cercospora and anthracnose leaf spots.

• 6

  Spray the entire privet bush with the solution, coating the foliage evenly. Fungicides won't cure current leaf spot infections, but it will prevent the fungus from spreading to healthy foliage. Remove infected foliage between fungicide applications.

• 7

  Reapply the fungicide at seven- to 14-day intervals until the fungus is gone or conditions no longer favor the spread of the spores. Most leaf spot diseases require wet or humid conditions, so further spraying isn't necessary during dry weather.