Hydrangea Information

Why don't my hydrangeas bloom?

This, by far is the most asked question at Chestnut Hill Nursery. Proper placement in your landscape and correct pruning of your hydrangeas, will increase your hydrangea's flower productivity. There are five basic types of hydrangea and each has it's own special needs.

Big Leaf Hydrangea (Hydrangea macrophylla)These are the mophead and lace-cap hydrangeas. The perfect location in your garden for these varieties are in a north or eastern exposure. They need full morning sun and a shady afternoon. The mopheads and lace-cap hydrangeas, bloom on last year's growth. You must prune them immediately after bloom (usually in late August or early September) otherwise, you will be pruning away next year's flowers. The "Endless Summer" have been cultivated to bloom on new growth. They are more cold hardy and the pruning time on these hydrangeas are not as critical. Prune to keep the size manageable.

Oakleaf Hydrangea (Hydrangea quericifolia) follows the same instructions as the Big Leaf Hydrangea for pruning and sunlight requirements.

Peegee Hydrangea (Hydrangea paniculata) Peegees bloom on new growth and can be pruned in the spring if needed. Cut back peegees leaving two buds at the base of each stem. This will encourage the shrub to produce larger flowers. If you chose to prune less severely, the hydrangea will be larger with smaller flowers. Full sun will produce the best flowering.

Smooth Hydrangea (Hydrangea arborescens) Two of the most common varieties of smooth hydrangea include Annabelle and Grand flora . These are very hardy in our zone, and can handle more sun than the macrophyllas. They bloom on new growth, and can be pruned (if necessary) in early spring.

Climbing Hydrangeas (Hydrangea anomola petiolaris) Pruning is rarely necessary, if needed however, remove only the unwanted shoots. that have strayed. Partial sun to light shade will yield the best results.

How do I change the color of my hydrangea?
Color on the Big Leaf Hydrangeas are determined by the soil pH. Color on the other varieties are determined by the actual hydrangea variety. Soil tests can be done to determine the exact pH. A pH of 7.0 to 7.5 will ensure that your flowers will be pink. "Blues" are determined by an acid pH (5.5 to 6.5) and the presence of aluminum in the soil. Acidic fertilizers can help achieve good "blues". Apply dissolved aluminum sulfate twice a year evenly applied over the roots. It may take a growing season to see the results of any color changes. Be patient!

Watering Needs of Hydrangeas

In general, hydrangeas like moisture. A newly planted hydrangea needs attention until it has acclimated itself to your garden. The broader the leaf and the more sunlight it receives, the more water it will require. Keeping the soil moist is very important. Overall, hydrangeas are hardy and easy to care for. Cold winds and frost are their greatest hazards. Plant choices and placement in your landscape can overcome some of these problems.