Azalea Culture
No other flowering shrub has contributed more to the gardens of America than the Azalea, especially when one considers that by properly choosing varieties, color in the garden can be had from October through June. Azaleas can be handled as pot plants, mass planting, specimens, tree types, espalier and hedges. The versatility of this plant is unlimited. However, most Azaleas are at their best when planted in groups or drifts. An ideal situation for them would be among high trees, so spaced, as to allow the sun and light to penetrate, yet providing intervals of shade to give the plants some respite from the hot sun. Where there are no trees, the north or east side of the house, or high fence, would be desirable. Although it is true that many Azaleas thrive in full sun, especially along the coastal areas, the Southern Indians are best suited for full sun planting.
CULTURE-SOIL
Azaleas may be grown successfully in various acid soil mixtures, such as leaf mold (redwood, pine and oak), sand and light loam, but for best results, pure peat moss or 2/3 peat and 1/3 soil planting have proven best. The hole need not be over 15” deep and 18 to 24” in diameter. Do not set the plant lower or higher than it was originally growing. Always soak peat moss thoroughly before using. Fill around ball of plant firmly, and make certain that good drainage is maintained.
WATERING
Azaleas, much like Camellias, should be moist at all times, but caution should be taken against their being WET at all times. Water well and deeply, but only as often as your own weather conditions demand. In areas such as Southern California, where summer months are dry and arid, one may generally expect to water once a week. Spraying of the foliage in the late afternoon of hot days is very beneficial.
FERTILIZING
Azaleas are basically light feeders and caution should be taken never to overfeed. Three to four feedings spaced from March through September (6 to 8 weeks) are sufficient. Cottonseed meal, or a commercial Camellia-Azalea food, should be used. In Southern California, use a tablespoon for each feeding of a plant which is about one foot high and one foot across. The labels on your fertilizer will generally advise you to cut the amounts in half for plants in containers. Never fertilize an Azalea when leaves show a yellow or paleness between the veins. This is usually caused by lack of available iron, and will, most often, respond to application of one of the many new chelated irons. Continue the use of iron, instead of fertilizer, until foliage becomes green.
PRUNING
Heavy pruning of undesirable branches should be done when they are at their peak of bloom and used as cut flowers. Most varieties of Azaleas require one good pinching or pruning of new spring growth in June or July, thus creating more branches and bushiness for fall bud setting. However, when plants are young and vigorous, such as the Southern Indicas, pruning on new growth should continue through September.
PEST CONTROL
While Azaleas are comparatively free of insects and disease, the most commonly encountered pests are aphids and mites, mites being the more serious. Consult your local nurseryman for the sprays best suited for your area and spray only as needed.