Spruce trees can be a focal point in the landscape, whether you have a single large specimen or several smaller ones. They are generally low-maintenance, resisting many diseases and surviving weather extremes reasonably well. Occasionally though, a disease or problem makes it past their tough exterior and you need to decide whether the spruce can be saved or if it will require removal.
When gall occurs, the first thing you are likely to notice are light green oblong growths near branch tips in spring. In fall, the galls turn brown and look similar to sea cones. The cause of these unattractive growths are Cooley aphids. The good news is that this condition doesn't pose any harm to a healthy spruce tree. If you want to avoid galls, don't plant Douglas fir and spruce near each other, because the aphids need to feed on both types of trees to survive.
Spruce trees naturally drop needles in the spring as new needles push out, but massive needle loss indicates a problem. Rhizosphaera needlecast disease, for example, causes needles to discolor in midsummer and then they begin dropping, en masse, by fall. The tree ends up with defoliated branches, which eventually weakens and kills the tree.
Fungicide treatments are sometimes successful at curing needlecast disease. You will also need to frequently rake and dispose of the fallen needles to avoid spreading the disease. If you do have the spruce tree removed, call a tree removal company, and plant a non-spruce replacement tree.
The cytospora fungus causes cankers on spruce trunks and branches. It isn't unique to spruces, but it can be deadly. The cankers first appear as an orange discoloration on the trunk or branches, which is usually noticeable in spring. As the canker surrounds the wood, it girdles and kills it. If the cankers are only on branches, then branch dieback occurs. If cankers form on the trunk, the girdling can kill the entire spruce.
Fortunately, cytospora primarily only affects damaged trees. You can prevent infection by mowing and trimming carefully near spruce trunks so bark damage doesn't occur. Don't dig deeply around the roots – damaged roots can be a major vector for infection. Regular deep watering every 14 to 20 days will also keep your spruce healthier and more resistant. Trees can sometimes recover from cytospora, but you will need an arborist to clean out and remove the damaged wood, and to find the root cause that lead to the initial infection.Share