Hydrangea trees are commonly used as flowering bushes in the home landscape, so learning how to care for them is an integral part of maintaining a lush landscape.
First and foremost, make sure your hydrangea trees are planted in a location that will allow full development. An ideal location includes plenty of space as well as some shade. By nature, hydrangea trees are woodland plants and require protection from the mid-day sun, which can burn the flowers. Of course, some morning and afternoon exposure to the sun is fine. The trees are tolerant of most soil types, but do better if the soil retains some degree of moisture. Keep in mind that the color of the hydrangeas blooms is directly affected by the pH of the soil. Even though you may have purchased a white Hydrangea, increasing the acidity of the soil can cause the blooms to change to more blue or purple shade. Likewise, increasing the alkalinity can make the tree produce pink flowers while a more neutral soil can cause white blooms.
When planting your hydrangea tree, the hole for the plant should be dug the same depth as the pot the tree came in and twice as wide. Remove the soil and mix it with peat compost and organic matter at a 50-50 rate. Make sure to fertilize your hydrangea tree in early spring. Apply the fertilizer near the trunk, extending your application to a few inches beyond the drip line from the leaves, since roots can extend that far. The fertilizer should be a slow release that contains nitrogen, potassium, and phosphorus in equal percentages. Immediately after the fertilizer is applied the tree should be watered thoroughly. During the growing season, the tree should be watered at the rate of at least an one inch of water a week, but make sure to water it even more during the summer. Mulching will also help with the trees need for water and the mulch should be applied 2-4 inches in depth starting at a distance 4 inches from the base of the tree. The mulch level can be increased to 6 inches during the winter months.
Pruning is also necessary to encourage new growth and for the overall health of the tree. Remove any spent flowers after the blooming is finished and pinch back branch tips occasionally during the growing season. The trees can be pruned back in the fall for shape or size, as well as to remove any dead branches.