Shubert Chokecherry

Description:

Normally, their new leaf growth will be green, and turn a reddish-purple color with maturity. New branch growth is a reddish color, and as it matures the bark will turn grey. This tree does have some small new branch growth and the reddish-purple leaves are in the stage of falling off the branches. This Shubert Chokecherry appears to be healthy overall, however upon closer observation there are a few issues with this particular tree.

Habitat:

This Chokecherry tree is located in Olds Botanic Garden Phase III right next to the west entrance gates. It is in a very sunny location with well-drained soil, beneficial for the preference of this plant.

Notes:

There is one branch on this tree that clearly has black knot disease. Sometimes young galls are overlooked and usually remain small for quite some time so there may even be more developing, and the disease can also spread to other trees through the air. The main solution is to prune the effected area removing at least 10 cm beyond the black knot and disposing of it properly. It will have to be monitored because the black knot can still develop after pruning. Fungicides may be applied for prevention. In addition, it is easy to spot holes in all of the leaves. Coryneum blight seems to be the suitable suspect here as it can be a common disease for this plant. Aphids will cause a misshapen, curled, sticky leaf type of damage when serious, and caterpillars would be more defoliating, which doesn't seem to be the issue. Although every leaf does have some shot holes, it seems to be a mild case. However, if it becomes a severe infestation this disease can effect the leaves and fruit quite badly, causing them to be lost. This disease will also effect the buds and branches. Since it is a fungal pathogen and can become airborne, it will persist in our wet weather and the best solution would be to remove the infected leaves, twigs, buds, and if there becomes infested fruit, dispose of them properly as well. In desperate need applying specific fungicides may also help. Another problem this tree has is aphids. There are plenty of aphids and their eggs on the underside of the majority of leaves. Usually spraying them off with cold, soapy water works well, but might not be the best solution if fungus is bothering the tree. On top of that, soap also has a negative effect on beneficial bugs, so always be careful when using any deterrents. Dormant oil will help with the eggs that are overwintering. Introducing adult ladybugs or lacewing larvae are great predators to introduce for getting get rid of aphids and their eggs in a natural way. Specific chemical pesticides may also be used in extreme cases. Each of these issues do not seem to be causing the plant any serious health concerns, yet, but by next season things could turn so it is best that this tree gets a good pruning and sanitization in. If things get worse, possibly even some chemical treatment for aphids and fungi would be needed.