Hydrangeas are old-fashioned favorites still grown as foundation plantings around houses of all architectural styles. Their large, showy flower heads appear in mid-summer and continue through fall. The flowers will dry on the bushes and remain long into winter on the leafless branches. Hydrangeas come in white, blue or pink varieties. Plant hydrangeas from starter plants purchased in spring or summer.
Choose a spot for your hydrangeas that is in full sun to partial shade. In hot southern zones, plant the hydrangeas in more shade so they don't wilt in the midday sun.
Improve the soil by adding two to four inches of compost and two inches of peat moss to the surface of the soil. Dig them into the soil by turning it over with a spade. Rake the surface smooth.
Dig a hole twice the size of the root ball. Put 1/4 cup of all-purpose granulated fertilizer into the bottom of the hole. Scratch it in with a garden claw. Partially refill the hole with soil.
Put the roots of the hydrangea into the hole. Back fill with soil and firm it down gently with your foot.
Form a ridge of soil around the planting hole using your hands. This will help the plant catch rainwater.
Set a garden hose to a slow trickle. Place the hose near the base of the hydrangea. Let it water the plant for 60 to 90 minutes.
Mulch the area around the base of the hydrangea with a four- to six-inch layer of organic mulch, such as hay or buckwheat hulls.
Fertilize monthly during the growing season beginning in May in the south and June in the north. Pull back the mulch. Apply 1/4 cup of granulated all purpose fertilizer in a eight- to 10-inch circle around the plant, without it touching the plant itself. Scratch the fertilizer into the soil and replace mulch.
Prune in spring by removing old, damaged or diseased growth. Do not cut new shoots as that is where the flowers will form. In late summer, prune again after the plants have finished blooming. Make the cut just above a bud that is facing the outside of the bush. If you want larger flowers the following year, cut out one third to one half of the upright stems.
Apply a protective winter mulch in late fall. Put down a 12- to 24-inch layer of fallen autumn leaves or hay on and around the plants to protect from freezing winter temperatures. Remove the mulch in early spring.