The care information provided in this section represents the kind of practical advice is available for all the plants in this web site if you subscribe to the monthly customized newsletter Yardener’s Advisor.
Azaleas require supplemental watering when they are first planted, in times of drought, or in late fall before the ground freezes for the winter. If they are planted in healthy soil with lots of organic matter in it to hold moisture and they are mulched, established shrubs can manage fine with normal rainfall. In thin soils or unmulched the shallow roots of azaleas will need frequent watering in hot weather and especially when rainfall is scarce. During periods of prolonged drought even well-established azalea shrubs will need about 1 gallon of water twice a week. Run a drip irrigation system or turn on a sprinkler for 20 minutes each time. Always mulch azaleas to conserve moisture near their very shallow roots. For information on products see the file on Choosing Watering Equipment
Feed azaleas once a year in the early spring or in the fall. Sprinkle all-purpose slow-acting granular fertilizer or a product formulated for acid loving plants on the soil around each shrub according to label directions. It will provide steady, consistent nutrition throughout the growing season. Spread it out to 1-1/2 feet beyond the tips of the branches for the rain to soak in. The healthier the soil, the less fertilizer you will have to use. The soil around azaleas that have been mulched faithfully is continuously improved as the organic material decomposes, adding nutrients and water absorbent humus to it. For more information see the file for Fertilizers
Consider Plant Growth Activators
There are on the market a growing number of products that will help your plants become healthier, more drought resistant, more disease resistant, and even more insect resistant. These products are generally easy to use and not terribly expensive. If you want to give your plants some oomph, check out New Technology In Plant Growth Activators
A 2 to 3 inch thick layer of organic mulch over the azalea’s root zone keeps the soil moist, and discourages weeds. It also harbors lots of beneficial organisms and conditions the soil as it decomposes. Spread an attractive organic material such as chopped (not whole) leaves, pine needles or wood chips on the soil under each azalea.
Leave the mulch layer on year round, renewing it periodically as it decomposes. Never put a layer more than 3 inches deep and do not pile it up against plant stems. In the winter mulch insulates the soil against fluctuating winter temperatures that cause it to heave and disturb azalea roots. For more information see the file on Using Mulch
Azaleas rarely require heavy pruning. Prune them lightly in the spring immediately after bloom to encourage denser growth and heavier flowering for next spring. Avoid shearing them. Simply pinch branch tips with thumb and forefinger or lightly clip individual stems and twigs with hand pruners. After bloom is also the best time to take out weak and dead branches, and to cut very old ones way back to near ground level to stimulate new growth for a well-shaped shrub.
Removing older wood stimulates younger branches to sprout quickly. Renovate and revitalize overgrown or aged azaleas with major pruning. Late May or early June (after bloom) are good times to cut back all branches severely, possibly all the way to the crown at soil level to encourage new sprouts. Or, rejuvenate a shrub over a three-year period, removing a third of the old branches each year. Cut each branch to just above the soil line with sharp loppers or hand saw, depending how thick it is. Do this by the middle of June to give the plants maximum time to develop new growth each year.
For more information see file on Pruning Shrubs and Hedges
Winter Protection of Azaleas
Since evergreen azaleas are only marginally hardy in many areas of the north, winter protection may make the difference in their survival. In the fall spray the foliage of those exposed to prevailing winds or direct sun with anti-transpirant spray, coating all leaf surfaces well. This will minimize the effects of drying wind and the glare of winter sun. Spray again on a mild day in late January. Mulch the soil over deciduous azalea roots well for winter after the ground has frozen. This will buffer the fluctuating extremes of temperature in the soil and prevent disturbance of their shallow roots. Take care not to pile the mulch up against azalea stems that may harm stem tissue and encourage rodent damage. If shrubs are at risk from drifting snow erect a screen of burlap or snow fencing around them, leaving some air space between the screening material and the tips of the branches. Never use plastic. See the files on Winter Protection For Plants and Plant Protection Supplies