My trees are forming new needles which is great. Yet there are some that are a bright rust color. Only 3 of my 16 trees have any at all and they are not throughout the tree. There is a grouping a new needles and just one may be the bright rust color. Is this an indicator of spider mites? Bayer makes a product which is systemically applied that kills spider mites. Is this safe for this type of tree? I have applied the fish bone meal fertilizer, which is the only change I've made except cutting back the watering.
Hello, Yoshino Cryptomeria naturally develops a rust colour, so be careful not to jump to conclusions. Here is a link to a nursery selling the plant. The picture shows the rust colour. Also this plant has few insect and disease problems, although, as you mentioned, mites do occur occasionally. Be sure that you identify that it is in fact an insect before you attempt to remedy the problem. Raakel
Thanks for the picture in helping me with my diagnosis. The difference is that these needles still look alive and have some green throughout. I experienced this in the fall. My needles are solid rust color and limp in the area where they are colored. Does that lead you to a different diagnosis? I apologize that I do not have a digital image to share so readily. It's on my Christmas list for '06 :)
Yoshino Cryptomeria is not susceptible to many insects and diseases. From what I have read leaf blight, leaf spot and mites all cause problems. Leaf blight and leaf spot can cause inner foliage and tips to turn brown. If the tips are limp, as you mentioned, it could be a leaf blight. In general mites cause stippling on the leaves. Have a close look for stippling or the mites themselves. It is difficult to suggest a treatment without knowing what the problem is. Raakel
