Hydrangea trees are colorful flowers that thrive in partial to full sunlight. Native to Japan and Korea, the hydrangea tree is a deciduous, shrub that produces colorful blooms of pink, white, blue, and purple. The hydrangea's color selection is based on its response to the soil's pH levels. The hydrangea is a relatively easy tree in which to root and care.
Choose a full to partially shaded area for the hydrangea tree. Dig a hole for the tree that is about the same depth of the tree's original pot and at least twice the width. Plant the tree in a moist, nutrient rich soil. Mix the soil with organic matter or peat compost at a 50-50 combination. Ensure that the soil is loose and well drained.
Purchase a soil test kit. Test the soil's pH levels to determine the potential color of the blooms. Increase the soil's acidity to produce blue or purple blooms. Increase alkaline levels in the soil to produce pink blooms, and neutralize soils to produce white blooms.
Fertilize the hydrangea in the early spring, just before the growing season begins. Use a well balanced, slow release fertilizer that includes nitrogen, potassium, and phosphorus. Reapply the fertilizer in May and July.
Water the hydrangea tree generously but avoid overwatering. Water the hydrangeas thoroughly with at least an inch of water on a weekly basis. Increase the watering schedule during the hot, dry summer months. The hydrangea is intolerant to drought conditions.
Prune the hydrangeas as necessary. Deadhead spent flowers after blooming is complete. Remove damage, dying, or wilting blooms, stems, and branches as they appear. Prune down the trees in the late fall, removing any spent flowers. Pinch back branch tips to control branching.
Apply a layer of mulch around the hydrangea's planting area, keeping the mulch at least 2 to 4 inches from the base. This will help to maintain the soil's moisture levels and reduce the growth of weeds around the area. Protect the hydrangeas from winter weather by increasing the thickness of the mulch to 4 to 6 inches.