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Hydrangea Care

by Chris Valley, Prides Corner Farms, for Woodland Gardens

Pruning Young, Newly Planted Hydrangeas
It is best to prune or pinch your young plant in order to build a full-bodied plant. If the plant is leggy when you purchase it, shear it back hard by 1/3 from its original size. Once it puts on an inch or two of growth, pinch the branch tips to remove just the tip. The tip controls the branching. Once removed, the buds below will turn into branches. Repeat this process a couple of times during the first growing season. This may sacrifice the blooms the first year, but it will result in a well-branched, full-bodied plant that will reward you with more flowers in subsequent years.

Care by Species

Hydrangea anomala 'Petiolaris' (Climbing Hydrangea)
1) No need to prune. Train on a wall or trellis.
2) Full sun to part shade.  Hardy to zone 4
3) Very adaptable, but proliferates in rich, well drained, moist soil.
4) Ph adaptable.
5) Strong growing vine that climbs by aerial rootlets, it is at its best when grown on the face of a brick wall. Blooms from June to early July; slightly fragrant blooms are 6-10 inches across.

Hydrangea arborescens (Smooth Hydrangea)
1) Prune in late fall or early spring. Flower buds are produced in late spring/early summer. Responds very well to being cut back to about 10 inches above the ground, which encourages stronger stems and larger flowers.
2) Full sun to part shade.     Hardy to zone 4
3) Grows 4-6 ft tall, 3-4 ft. wide.
4) Only use a slow release fertilizer during the first year to establish the plant. Once established, do not fertilize.
5) Very adaptable to soil conditions; prefers rich, well drained, moist soil.
6) Ph adaptable.
7) Most popular cultivar is 'Annabelle' because of the large symmetrical blooms, which can reach 14" across. Widely used in the Northeast because it blooms on new wood and reliably blooms each year. This cultivar does have a tendency to collapse under its own weight and may require staking.

Hydrangea macrophylla (Big Leaf or Mophead Hydrangea)
1) Prune after it has bloomed (mid July to mid August). Cease pruning by mid August to allow time for buds to form prior to winter.
2) Partial shade. Hardy to zone 5.
3) Grows 1-5 feet tall depending on cultivar.
4) Needs high moisture. Moisture is a necessity of this plant.
5) Very popular category because it is the most colorful of all the species. Categorized into two groups – mopheads and lacecaps. Mopheads are large round clusters of sterile flowers and lacecaps are flat heads containing fertile and sterile flowers.
6) Hydrangea macrophylla is unique for several reasons. It sets its flower buds in the fall and overwinters them. A hard winter can kill the buds and eliminate flowering. An early fall or late spring frost can also result in a loss of flowers.
7) New varieties like 'Endless Summer,' ' Blushing Bride, 'Twist & Shout' and the 'Let's Dance' series have the ability to bloom on new and old wood alike, thus eliminating the danger of losing flowers.
8) Fertilize in early spring by applying a slow release fertilizer.
9) Flower color on most varieties is affected by the pH of the soil. Blue flowers need a more acidic soil and pink flowers need a more alkaline soil. A pH below 6 is acidic, above 6 is alkaline. To turn pink flowers blue, add 1 tablespoon of Aluminum Sulfate to a gallon of water and slowly water the plant. To turn blue flowers pink, dust lime around the dripline of the plant and water in well.

Hydrangea paniculata (Panicle Hydrangea)
1) Prune in early spring. Blooms on new wood. Very tolerant of a hard prune. Cutting the plant back by half each year will result in larger flowers and a fuller plant.
2) Full sun to part shade.   Hardy to zone 4
3) Grows 6-8 feet tall and wide.
4) Prefers good, loamy soil. Most adaptable of all the Hydrangeas to different soil types.
5) Very tolerant and hard-to-kill plant!
6) This is the hardiest species of Hydrangea, commonly referred to as P.G. for short. This plant is noted for its abundance of sterile blooms. Also offered as a tree form.

Hydrangea quercifolia (Oak Leaf Hydrangea)
1) Prune in early spring. Blooms are produced on new wood.
2) Full sun to part shade (does best in part shade).   Hardy to zone 5
3) Grows 3-6 feet tall and wide depending on cultivar.
4) Needs well drained soil, otherwise very tolerant of different soil types.
5) Fertilize in early spring with a slow release fertilizer.
6) A great landscape plant. As the name indicates, it has an oak-shaped leaf. It is noted for its burgundy red fall color. It blooms in late June to early July and flowers open white and fade to a pleasing pink and then a rich brown in winter.