One of the most striking flowers on display in florist shops is the azalea. Available in various patterns and shades of pink, rose, red crimson, orchid and white, azaleas give just that brilliant touch of spring that is needed in homes at this time of year.
Don't confuse florist azaleas with varieties planted outdoors in the landscape. Although they have similar growing requirements, florist azaleas are not hardy if planted outdoors.
To extend flowering, place azaleas in a cool spot with bright light. Although azaleas will hold up amazingly well in a warm, dry location, they will bloom quickly and blossoms will only last a short time. Plants benefit from humidity and an occasional syringing of foliage with tepid water is desirable.
Azaleas like to be kept moist, but not sopping wet. Most soils are lightweight and composed of mainly peat moss. They'll dry out quickly, and the plant will wilt. Plants may need to be watered daily or every other day.
Containers should have drainage holes. Leave it in the water until bubbles stop rising, then remove and allow the excess moisture to drain off.
Azaleas of all kinds require acid soils. Yellow or chlorotic foliage usually indicates that the soil is too alkaline, resulting in an iron deficiency within the plant. Adding either chelated iron or iron (ferrous) sulphate will help remedy or prevent this condition. A variety of houseplant fertilizers are available which acidify the soil while they provide an iron supplement. Use one of these to avoid or correct problems.
A word of warning: yellow leaves may also be the result of growing plants under conditions that are too warm and dry.
Reblooming your florist azalea for continued enjoyment next year is possible, but can be challenging. After you have enjoyed the blooms, and when outdoor temperatures are above freezing, place your azaleas outdoors for a summer vacation. Avoid direct sun, and be sure to check the plant daily for watering needs.
Before midsummer (July 1), carefully shape the plants by removing tips of all rapidly growing shoots. Continue to water and fertilize regularly.
In September, bring the azalea indoors to a cool room with full sun. Provide temperatures of 40 to 50 degrees F from November until the first of the year. Cool temperatures are needed for flower bud development and without them few, if any, flowers will form. Withhold fertilizer applications, and reduce watering.
As buds continue to develop and swell in January or early February, move your plant to a sunny window in a somewhat warmer room and apply fertilizer. The temperature for forcing flowers should be near 60 degrees F at night (10 to 15 degrees warmer during the day), with plenty of humidity in the air.
In a few weeks, flowering begins–and your efforts will be lavishly rewarded. At excessive temperatures, buds may "blast."
To prolong flowering, remove green shoots as they develop around the flower buds.
Source: David Robson, University of Illinois Extension horticulture educator, Springfield Center, (217)782-6515
