The hydrangea tree, also known as the peegee, panicle or grandiflora hydrangea, originates from Japan. Its scientific name is Hydrangea paniculata. The hydrangea tree may reach heights of 20 feet, bearing white flowers that fade to pink in late summer. Flowers, which develop on the new wood each year, grow into large conical flower clusters that may become so heavy they cause their stems to droop.
Select a location for your hydrangea where it will get morning sun and afternoon shade. Hydrangeas tend to bloom best with three to four hours of direct sun daily, according to the University of Georgia, but hydrangea trees will tolerate full sun better than other hydrangea varieties.
Amend the soil where you wish to plant your hydrangea. Prepare the bed by tilling an area 6 to 8 inches deep and about 3 feet in diameter. Work in compost or aged manure as well as a slow-release fertilizer. Dig a hole twice the size of the pot the hydrangea is currently in.
Remove the hydrangea from its pot. If it has tightly bound roots wrapped around the outside, cut into the roots in three or four places so you can break them up a bit and encourage them to grow outward.
Spread the roots out somewhat as you place the plant in the hole with the top of the root ball about at soil level.
Fill in and firm the soil around the plant slightly. Water the hydrangea until water pools around the base.
Mulch around the hydrangea with about 2 to 3 inches of mulch, but keep the mulch from touching the hydrangea stem.
Water the hydrangea regularly during the first growing season. Water once to twice weekly with a good soaking. Determine when it is time to water by checking soil moisture about 4 inches below the surface. If it is moist, delay watering until it is dry at that depth.
Apply a time-release fertilizer around the hydrangea tree each March according to package directions.
Prune your hydrangea tree depending upon your preferences. For larger blooms on a smaller plant, the University of Georgia recommends cutting the tree back substantially in early March, leaving just two buds at the base of each stem. For a larger tree with many smaller blooms, allow the plant to grow un-pruned.