How To Care For A Spirea Plant
Voted one of the easiest shrubs to grow, the flowering spirea plant is often used as a foundation for hedges or in perennial gardens. Most of them begin blooming in the early spring and continue to do so until the midsummer. Flowers are vibrant and depending on the variety of the plant, they can be pink, yellow, white or red and some even have colorful foliage in the fall. The size of the spirea plant also depends on the variety but they can be as small as 2 feet tall or as big as 10 feet tall.
Some varieties of these plants have been used by garden enthusiasts for more than 300 years. Related to roses, they are extremely tough and once they are established, they are completely drought tolerant.
Planting Instructions
These plants need to be planted in either the spring or the fall. When planting multiple shrubs to use as a hedge, they can be placed anywhere from 2 to 15 feet apart. The distance will ultimately depend on the size that the plant is expected to mature at.
The hole that you dig only needs to be as deep as your plant's root ball and about three times as wide. If the soil that you are using is in poor condition, you need to amend the soil that you took out of the hole with a bit of compost. If it is already in good condition, you don't need to amend it at all.
Carefully remove the root ball out of its container and place it in the hole. Fill the hole back up with the soil that you removed from it and be sure that it is packed firmly. Water your spirea plant thoroughly and form a bit of ridge that is somewhat raised in the soil around the entire perimeter of the hole. This ridge will assist with holding the water where it needs to be.
The spirea plant grows best in well-drained soil but they have been known to tolerate unfavorable soil conditions. They do require a lot of sun. They can survive in partial sun but to bloom at their full capacity, they prefer direct sun. The one exception to this rule is the yellow foliage variety, they are the only kind that flourishes in the shade.
General Care
These plants are not heavy feeders however they do appreciate a 10-10-10 fertilizer once a year. Most are exceptionally winter hardy so special protection is generally not needed. It is recommended to apply a thin layer of compost directly under the shrub every spring and spread it out to the perimeter of the branches. A two inch mulch layer will help to control weeds and retain moisture.
Although they are drought tolerant, during the summer months when there is less than one inch of rain per week, the plants should be watered. When flowers are spent, often deadheading will help induce a second flowering. Pruning after flowering is recommended to maintain desired shape and reduce height. Diseased, dead and broken branches can be removed from your spirea plant anytime. It is really not possible to prune these plants too much. Keep in mind that they bloom entirely on new growth.
Diseases And Pests
There are a few diseases that will infect a spirea plant. Powdery mildew is the mot common. This is a white fungus that looks like powdered sugar. Most of this grows on the surface of the leaf but some can penetrate buds and small twigs. Spirea aphids are another problem. They occur in very large quantities and feed on the leaves which cause them to curl, pucker and distort. In the warm weather, they produce young females who can all then reproduce alone. Overcrowding will cause winged aphids to be born that can easily relocate from branch to branch. It is important to check your spirea plant often to assure that it is disease and pest free.