Cryptomeria Problems

Cryptomerias belong to the conifer family, even though in English the tree is colloquially referred to as a Japanese cedar. The trees are evergreens and produce small cones. It is common for these trees to grow up to 50 or 60 feet high and to spread their canopies over more than 20 feet. They thrive in full sun and do not usually suffer from pests. Nevertheless, there are a small number of problems associated with cryptomerias.

Cryptomeria Red Mite

Mites are a known pest that attacks junipers. Cryptomeria trees in particular may suffer from an infestation with a red mite that damages the needles. The pests attack during cooler temperatures. If you gently shake a tree limb over a white piece of paper and more than 20 mites land on it, you can save your Japanese cedar's health by spraying the tree with a mite killer specifically labeled for use on cryptomeria.

Leaf Blight

If you notice that your cryptomeria has a lot of dead or dying branches that contain brown or rust-colored needles, the tree may suffer from a fungus. This dieback associated with the dark spots may be due to leaf blight, a fungal disease. You may see good results if you remove as many of the fungus affected branches as possible. Experts at the University of Washington Botanic Gardens suggest cutting the branches back to tree trunk level--if there is a lot of brown on them. You may selectively clip off affected bits and pieces of foliage if you deal with only moderately affected branches. Thereafter, you need to follow up the branch removal and pruning with a fungicide spray and cover the entire tree.

Root Rot

Cryptomerias may fall victim to root rot if they are planted in soil that does not drain properly. It is interesting to note that these trees will endure clay and sand, as long as the soil is well-draining. Because the Japanese cedar tolerates droughts only moderately well, caretakers may overwater the trees when erring on the side of watering too much rather than too little. You can recognize root rot by the discoloration of the Japanese cedar's foliage. If the tree is still small enough to replant, consider moving it to a more favorable spot in your yard. If the tree is too big for replanting, improve the drainage of the soil. Fill in any low spots underneath the tree's canopy where water may pool. Use topsoil to create a gentle slope that leads water away from the tree. Remove dead leaves and ornamental bark from around the tree trunk since these materials trap moisture.