Hydrangeas have been a favorite in both urban and country gardens for generations. They are known for their beautiful pink, blue or white blossoms. In landscape design they are often used as a specimen planting or in mixed borders within the garden. The shooting star hydrangea is a lacecap cultivar (H.macrophylla var. normalis) and, like most hydrangeas, it is easy to care for.
Shooting star hydrangea is a deciduous shrub; a mature plant will reach a height of 3 to 5 feet and a width of 3 to 5 feet. The (double) flowers are white and star-shaped. They stay pure white for approximately four to six weeks, and then they change to a greenish color. The greenish color blooms then last for an additional four to six weeks. Hydrangea varieties that have pink or blue blossoms are rather unusual in that the color of their blossoms is determined by the pH of the soil (acidic soil produces blue blooms and adding lime to the soil produces pink blooms). However, the blossoms of white hydrangeas cannot be changed by the pH of the soil; they remain white no matter what the pH of the soil is.
This shrub should be planted in organically rich, well-drained soil. (If you have heavy clay soil, you will need to add compost or peat moss to it.) The shooting star hydrangea grows well in slightly acid soil with a pH of 6.1 to 6.5. It does best when planted in a partially shaded area-ideally a northern or eastern exposure. Shooting star is hardy in zones 5 through 10.
Watering and Fertilization
Hydrangeas require frequent watering during the summer months. The addition of 3 to 4 inches of mulch around the circumference of the plant will help to retain moisture. The mulch also keeps weeds down. Hydrangeas can be fed with 10-10-10 plant fertilizer once or twice in the summer season; follow the manufacturer’s directions.
The shooting star hydrangea produces blossoms on the previous year’s growth. Therefore, it should be pruned after flowering is complete and before new buds are produced on stems for the next spring’s flowers. Pruning should be done in the summer season, before the month of August; flower buds for the next year’s flowers will be produced on stems in the months of August, September or October. Deadheading (removing spent blooms) can be done in June or July. When deadheading in August, remove the flower and a short part of the stem to avoid removing any of the next year’s buds.
Pests and Disease
Aphids can be a problem for all cultivars of hydrangea. An infestation of aphids can be controlled by using an insecticide. Mites may also attack the hydrangea and usually appear during extremely hot, dry weather. The best defense against mites is maintaining a healthy tree (adequate watering) during hot, dry weather. Insecticides are not effective against mites. Leaf spots are a common problem, occurring in late summer and early fall. Leaf spots are more unsightly than damaging to the plant.