Perhaps you planted young azaleas close together to achieve instant effects. Within a few years, those young azaleas will be crowding each other. Unless you remove some of them, they will grow tall and spindly.
September is the best time of the year to dig and transplant azaleas, rhododendrons, andromeda, mountain laurel, blueberry and related species. By early September, the plants have stopped growing and are setting flower buds. When plants stop producing stems and leaves, they start producing roots. Thus, transplanting in September gives the plants time to establish themselves and be ready to resume normal growth in the spring when they begin to flower.
When transplanted in the spring, the plants will flower, but new growth will be limited because the plants have to grow new stems, leaves and roots at the same time.
Azaleas and related species are very particular about where they grow. Unless irrigated during drought, they are best grown in light shade. On the other hand, the more direct sun plants receive, the more flowers they produce. Under dense shade, they will produce good dark foliage but few flowers.
It is always best to grow these plants in deep organic-rich soils that are acid in nature so they can absorb nitrogen in the ammonium form. Ammonium nitrogen is more readily available in acid soils than in neutral soils such as those good for growing annual flowers and vegetable gardens.
To avoid problems, have your soil tested before planting. A good soil test will provide the pH of the existing soil, the amount of calcium and magnesium present as well as other essential nutrients essential for good plant growth. Never fertilize these species with lawn fertilizers; they contain nitrogen in the nitrate form, which will cause stunting.
Acid soils tend to lack calcium, which is essential for good growth. Calcium is as important in plants as it is in humans. Thus, to supply calcium without making the soil neutral or alkaline, blend a few tablespoons of gypsum (calcium sulfate), into the soil before planting. If the soil is low in magnesium, add a tablespoon of Epsom salts, which is magnesium sulfate.
Successful transplanting also depends on careful watering. A newly transplanted shrub or tree should be watered thoroughly at three-day intervals. Light daily watering does more harm than good.
Ask Dr. Gouin your questions at DR.FRGouin@gmail.com. Please include your name and address.