Azaleas need acidic soil, mulch and moisture

Q. Enclosed is a photo of one of my azalea bushes. I moved my two bushes nearly two years ago from another location. They survived the move but have been growing pretty much only blossoms. There are leaves on both but sparse. The blooms grow in a large bouquet-like fashion, last only about two weeks, then fall off. Should I pinch off the buds when they set this fall to encourage the bushes to leaf out? Or, do you have another remedy to help? Also what is the name of this azalea?

A. Your azalea plant is beautiful and easily identified by the five stamens. Unfortunately I cannot give the variety as there are so many different varieties with similar colors. I recommend for all gardeners to draw a map, labeling their plants when they are first planted, for their own records. Usually any label falls off within the first year or two. Some gardeners take the label off the plant and put it in with their plant records.

Several factors can limit the amount of growing leaves. Soil is one of the exacting conditions for raising azaleas and rhododendrons, as it has to be on the acid side — below 5.5 — with good drainage. Most of these types of plants have fine fibrous roots within 4 inches of the top of the soil. The soil must be constantly moist but with good drainage.

A mulch of shredded oak leaves works best for lower acidity and supplies more plant nutrients than pine needles would. Some pine needles worked in with the oak leaves will keep the oak leaves from blowing away. This mulch will help in keeping the soil cool in summer and warm in winter. The mulch should be about 4 inches deep. Another addition of seaweed added from time to time will help out with trace minerals. Do not add any animal manure as it breaks down and raises the soil’s alkalinity.

Check your water, too. It may contain lime, raising the pH over time.

Most azaleas require just a feeding of cottonseed meal right after they have finished blooming. Apply it at the rate of 2.5 pounds per 100 square feet. Just sprinkle this over the surface of the mulch and water it in. You do not have to work this in as you may damage the shallow roots. You may re-apply about three weeks later, but not later than the last week of June. If you fertilize later than this, the new growth will not have time to harden off before the heat of summer starts.

If these plants are grown in too dense of shade or are overfed, they will not handle the winter temperatures well.

You can prune off the flowers after they have finished blooming to prevent energy of the plant going to help develop seed so this energy can help with leaf growth. You can sacrifice floral buds that are starting to form right now for next year’s flowers and also shape your plant into a desirable form. The more branches your azalea has, the more flowers will be possible. So you may give up some flowers next year to get your plant in shape and produce more leaves.

This story was originally published May 28, 2015 at 5:00 AM with the headline "Azaleas need acidic soil, mulch and moisture."