How to Care for Poplar Bark

Prune off branches next to the branch collar to prevent causing branch stubs. Branch stubs are not only unsightly, but they also create a flat stub where water can accumulate. Water accumulation promotes disease. To prevent branch stubs, cut 45-degree, downward angles next to the branch collar. The branch collar is the area where the branch attaches to the main trunk.

Fix split bark areas on the trunk. Spit bark areas occur naturally when the air temperatures fluctuate between freezing and warm weather. It also can be caused by mower's blades hitting the base of the poplar. To fix the split bark area, use a sharp knife to cut an oval around the wound. The cut should go into the bark 1/2-inch deep and through the healthy wood.

Fertilize poplar trees with damage to their bark caused by hypoxylon canker and nectria disease. Hypoxylon and nectria cankers are caused by a fungus that kills the outer bark. While there are no fungicides to treat both diseases, fertilize the poplar with a complete fertilizer that has a NPK (nitrogen, phosphorous and potassium) ratio of 10-10-10 in the spring.

Apply a 2- to 4-inch layer of mulch 2 inches from the base of the tree and extendig out to between 3 and 6 feet. Mulching conserves soil moisture, which helps poplars heal from fungal diseases like nectria. Also, mulch prevents weeds from competing with poplars for the soil's nutrients.

Water poplar trees during dry spells to help the tree survive bark damage. Give the poplar tree water from the base to the dripline. The soil must be moist 8 to 12 inches deep for the poplar to get enough water.