Hydrangea is an easy to grow summer blooming shrub.
Soft shadings of white, ivory, pink, lavender and blue make Big Leaf Hydrangea (Hydrangea macrophylla) the most commonly grown hydrangea in the US. The wide choice of colours are easily introduced into cottage gardens and urban landscapes. Smooth Hydrangea (Hydrangea arborescens) presents large and grandiose flower heads and is a popular choice in temperate climates. Hydrangeas are available in a multitude of species and varieties to spice up your garden.
Choose Hydrangeas By Planting Zone
Although some varieties of hydrangeas will survive in U. S. Plant Hardiness Zones 4 or 5 (the northern part of the Midwest), most of these plants prefer warmer temperatures. Select varieties adapted for your growing zone. Hydrangeas love sunshine--choose a location that receives at least six hours of sunlight a day.
Prune your hydrangeas when only absolutely necessary. Hydrangeas bloom out of last year's growth, so pruning will remove the flower buds. To maintain the plant's shape or remove damaged branches, prune it immediately after the plant blooms but never later than the first of September. New flower buds form in the autumn when night temperatures cool.
Add aluminium sulphate to the soil to change the colour of your hydrangeas from pink to blue. Hydrangeas are one of the few plants that can absorb aluminium from the soil.
Do not over fertilise hydrangeas. Stop fertilising after flowers fade. Fertiliser promotes leaf growth, not blossoms. After flowering, reduce the amount of water the plant receives and let the plant wilt a bit. Water restriction does not harm hydrangeas but encourages flower buds.
At the sign of the first frost, mulch hydrangeas with a thick layer of pine needles, straw, or oak leaves. Do not use maple leaves as a mulch since they compress when wet and can suffocate your plants. Layer the mulch as deeply as possible around the base of the plant. Cover young plants entirely with mulch, including the tips of the branches.