Strawberry tree leaf spot

Brown and black spots on strawberry tree leaves and fruits.

Also known simply as spot anthracnose, this disease infects strawberry trees. Symptoms are the presence of brown spots with a red or purple perimeter on leaves.

There are several strands of this disease, but all can be treated in the same manner.

This fungus will spread until all the leaves are contaminated. Leaves will drop off.

Strawberry tree leaf spot

Black and yellow spots on a strawberry tree leaf, arbutus unedo.Preventive care

The most effective way to protect the tree is to give it an excellent growing environment.

  • Rich and very well-draining soil.
  • Regular fertilizing if the soil is very poor.
  • Regular watering over the first 2 years to make sure it settles in healthily.
  • Space around the tree for air to circulate and to avoid moist air around the tree.

At the end of winter, spray Bordeaux mixture 2 to 3 times, at a two-week interval.

Curative care

As soon as the fungus appears, collect fallen leaves, burn them or dispose of them in a place that won’t risk contaminating your plants.

There isn’t any natural product to use that can definitely eliminate this particular type of fungus, but you can reduce its spread with Bordeaux mix. Best of course is to remove any infected parts beforehand.

Using bordeaux mix and even fungus-killing fermented weed teas is better than to spray with mancozeb or myclobutanil based solutions, which are fungicides sold in horticulture stores.

What causes spots on strawberry tree leaves?

Spots are round, purple and spread on both leaves and twigs

You’re dealing with the more severe of these fungus, Elsinoë mattiroloanum. It’s quite aggressive and must be taken care of quickly.

Spots are a blend of brown and purple and are oblong in shape

This is an infection by Ruptoseptoria unedonis. It’s part of the family of septoria leaf spot fungi.

Spots are brown with reddish edges and are of a roundish shape

This is a variant that is most common in British Columbia, in Canada. It’s name is Didymosporium arbuticola Zeller.

These three fungus spread most when the weather is warm.

  • Note: these fungus aren’t toxic to us humans. If ever your tree is infected, you can still harvest its berries to make arbutus berry jam without any risk at all.

Read also

On the topic of strawberry trees:

Other diseases and treatments related to leaf spot:

Credits for images shared to Nature & Garden (all edits by Gaspard Lorthiois):
Infected strawberry tree leaf and fruit by Luc Coekaerts under Public Domain
Single leaf by Al Funk of the © Canadian Natural Resources, Canadian Forestry Service, Laurentian Forestry Center