How to Stop Catkins From Forming on a White Birch

Check the tree for signs of stress due to pests, such as bronze birch borers, or girdled roots or drought. The reproductive systems of some plants, when under stress, go into reproductive overdrive.

Look for symptoms of drought stressors, such as wilting, curling and yellowing leaves. A tree stressed and weakened by drought becomes an easier target for pests and diseases. To keep white birches in good condition during drought, measure the trunk diameter at your knee height and give the tree approximately 10 gallons of water per inch of trunk diameter at each watering.

Apply preventive and protectant insecticides if you see signs of the bronze birch borer, a small slender beetle slightly less than 1/2-inch in length. Its larva feeds just under the bark of birch trees, which can result in sudden wilting and death, according to the Ohio State University Extension. The first signs of damage are when the top part of the tree suddenly wilts and dies; heavy attacks and continued infestation will kill all branches from the top down and, eventually, the tree itself. The branches and trunk will show raised ridges or bumps, called gouting. Protectant insecticides are applied to the tree bark so that the residual insecticide can kill newly hatched larvae. Contact your local agricultural extension office for currently registered pesticides and whether there is a timed schedule for application.

Examine the birch tree and its leaves for evidence of leafminers, whose larvae feed, or "mine," plant tissues through the middle of birch leaves. Related to wasps, the adults are small, black, four-winged sawflies that are approximately 1/8-inch in length. Affected leaves turn brown and might also look blotched or blistered. Trees, seen from a distance, have a disease-like scorched or blighted appearance. Repeated infestations and loss of leaves will weaken the tree and eventually cause its demise. The University of Rhode Island notes that the leafminer is normally controlled by parasitic wasps in its native Europe, but it can be treated with insecticides. Check with your local extension office for registered insecticides.

Cut away any roots that are choking, or girdling, the tree at the trunk with a hammer and sharp chisel. According to the West Virginia State University Extension, the first sign of a girdling root is often the gradual decline of a branch or branches on just one side of the tree's crown. Eventually, an entire side of the tree will be dead. Evidence of root girdling can frequently be seen at the tree's soil line, which will show a slight to moderate, if not greater, buttressing. Girdling occurs after a tree is planted in a hole too small for its outspread roots. Roots eventually cut into the tree and choke it.