PROVIDE GREAT SUMMER GARDEN COLOR...
Hydrangeas are one of my favorite deciduous shrubs to use for summer flower color. The combination of large decorative flowers and bold, dark green leaves provides a pleasing contrast with other garden shrubs. In addition to being showy in the garden, the blossoms can be cut and dried and used in year-round arrangements.
The four types most often grown here are the 'common garden hydrangea' and the 'lacecap' (macrophylla); 'Peegee' (paniculata Grandiflora) and the 'climbing hydrangea' (petiolaris). Plus, the large flowering greenhouses grown (potted plants) are often planted into the garden, once they have finished flowering indoors. The 'Oakleaf' hydrangea is another variety that is gaining in popularity because of its early-summer flowering season.
Hydrangeas are one plant that likes to be protected from the hot mid-day sun. Often when the leaves are a yellowish green, instead of the typical dark green, it is because the plant is situated in a spot where it is exposed to too direct sun exposure or too much reflected sunlight. If this is the case, transplant them to a semi-sunny spot and the plant should respond with better leaf color and possibly more flowers.
COMMON GARDEN HYDRANGEAS
I think one of the best new ones is the variety of 'Pink Elf'. It is a miniature French hydrangea that only grows about 11/2 feet high and up to 3 feet wide. It is a prolific pink flowering, bushy plant, with the typical large ball shaped hydrangea flowers. Some hydrangea varieties get so large and hard to manage, where as this one is easy to grow, with minimal pruning or care.
There are many other varieties of the bigleaf large flowering garden hydrangeas, all of which merit a spot in the garden. However, a couple of the large flowering newer ones that I favor are 'Nikko Blue' and 'Red 'n Pretty'. Keep in mind these are my personal favorites. There are all kinds of new varieties, many of which you might like even better. So my advice is to select them when they are in bloom, and since they are grown in containers, they can easily be transplanted at that time. Most the varieties of this type grow 4 to 6 feet or higher.
One important factors, is that the bigleaf hydrangea flowers often vary in color by soil conditions. For example, if the soil tends to be on the acid side the flowers tend to be blue. If the soil is neutral to slightly alkaline the flowers tend to be pink. So by liming the soil or feeding with superphosphate, flowers can be kept pink or red. Blue flowers may be made or kept blue by feeding with aluminum sulfate. This feeding should be done in about mid-February.
The delicate flowers come in shades of blue, white, pink or rose depending upon the variety. This type has unusual flowers, consisting of large sterile florets along the margin, and small fertile flowers in the center. The flower clusters are flat instead of the typical round shape of most types of hydrangeas. The botanical name for the 'lacecap' is the same as the common hydrangea, H. macrophylla. Flower color of some varieties is subject to change, depending upon soil. Feed them like you would the common hydrangeas.
Four of my favorite varieties are 'Button's and Bows', pink to 3 - 4 feet; 'Bluebird', blue to 4 - 6 feet; 'Lanarth White', white to 3 - 4 feet; and 'Mariesii', pink 4 - 6 feet. Some of the older varieties are apt to grow a bit taller, unless one keeps them pruned for size and shape.
A very attractive summer flowering vine, with white 'lacecap' flowers. This vine can grow up to 50 feet or more, clinging to any rough surface by aerial roots. The flat 'lacecap' flowers appear in June and are often 6 to 8 inches across in the northwest garden. The prettiest ones I have seen are have been grown on the east or north side of the house. In fact, I was at Van Dusen Gardens in Vancouver B. C., last year in June when their climbing hydrangea was in full bloom (planted on the northside) and it was spectacular. Hydrangea petiolaris, the climbing hydrangea is a deciduous vine.
'Peegee' is the common name for H. paniculata 'Grandiflora'. This variety is noted for its long, slender 'cone shaped' white flowers that fade from pink to bronze. The flowers, up to 12 to 15 inches long, are at their peak in late August and early September. This variety grows best in full sun or part sun and shade. This variety can become a large shrub, up to 15 feet in height.
This one gets its name from the shape of the leaves, which are somewhat shaped like the red oak. It blooms freely from July to September with large trusses of white flowers. Autumn leaf color is a beautiful crimson to scarlet. Does well in full sun. Plants will grow up to 6 feet or more.
Varieties that bloom after June should be pruned during the winter. I recommend Mid-February as the ideal time to prune them. Cutting off flowers for drying, is also an excellent way to keep plants within bounds. Avoid severe pruning, as it often results in the development of lush stem (vegetative) growth and as a result, poor flowering.
DRYING THE FLOWERS
My wife Myrna says the best time to cut the flowers for drying, is when you touch them and they have the texture of paper. Then simply put them in a dry vase, or you can hang them upside down in a cool, well-ventilated place to dry.
The best time to transplant established plants is during the winter dormant season months of November to February. Newly purchased, container grown plants can be planted at any time.