What do azaleas need

Windy sites are problematic: in winter, winds and sun can desiccate the foliage, of evergreen azaleas especially. Deciduous azaleas are more forgiving. Azaleas need good soil structure and plenty of organic matter so that their shallow roots will not dry out. Conversely, azaleas can be suffocated by excess water and poor drainage; soil compaction around foundations and in yards is a frequent problem.

When amending the soil, it is better to prepare the entire bed rather than just the planting hole to create a uniform condition so that the fibrous roots are encouraged to spread.

Azaleas and other Ericaceous plants prefer a soil pH of 4. Test the soil in the planting bed; if it is too alkaline above 6 , use pelletized sulfur to increase the acidity; coated sulfur releases over time so the change is gradual.

Read the package instructions to determine the quantity of sulfur needed; apply half the amount in September and the other half in April. Test the soil again the following fall to see if the process needs to be repeated. For more inspiration visit the amazing, new Azalea Garden.

Azaleas are not heavy feeders: feeding on a two- to three-year cycle will probably be sufficient. Smaller varieties look best at the front of a border, or in pots. Indoors, grow azaleas in a well-ventilated room with dappled or indirect sunlight. Use peat-free ericaceous compost for pot-grown azaleas. Water well, ideally with rainwater. Mulch outdoor azaleas annually with an acidic mix of leaf mould or conifer bark chippings.

For pot-grown and indoor azaleas, replace the top layer of compost, or repot completely in early spring and feed weekly with an ericaceous fertiliser. Try to keep the compost moist, but use rainwater as much as possible — tap water may be too alkaline. There should be little or no need to prune, but deadheading will improve the look of your azalea, while also encouraging it to bloom for longer. Pot-grown azaleas are often gifted as house plants at Christmas. These have been forced to flower out of season and, as such, may be tricky to look after.

For best results, keep the compost moist — sitting the pot in a larger container of water for several minutes once a week can be useful. A weak solution of black tea can also be good for azaleas, as it can increase the acidity of the compost.

Deadhead spent blooms regularly to prolong flowering, and then keep in a cool room for the rest of the year. To instigate flowering the following summer, feed weekly, and repot as mentioned above.

With luck, your azalea should flower again. Here are answers to some basic questions readers ask about these popular shrubs. Do azaleas need shade or sun? Actually, they like a little of both but not too much of either. Plant them in blazing hot sun, and they may suffer leaf scorch or become targets for leaf-sucking pests such as spider mites and lace bugs.

Plant them in dense shade, and they won't bloom. A good location is where they receive either dappled sun all day or sun in the morning and light shade in the afternoon. What kind of soil do they like? Azaleas do well in moist, acid pH 5. They won't grow in heavy clay, pure sand, or alkaline soil. If your existing soil is too bad to fix, plant azaleas in raised beds or containers. Heading refers to the cutting back of a branch, not necessarily to a side branch. This method is used to reduce the size of a plant, create a hedge or to renew old overgrown plants.

Renew overgrown plants by cutting them back to within 6 to 12 inches of ground level. This practice results in abundant new growth by midsummer. The best time to renew azaleas is before spring growth begins.

Renewal pruning before spring growth, of course, means that flowers are sacrificed for that year. After renewal pruning, prune the tips of new shoots when they are 6 to 12 inches long, to encourage branching and a full canopy. Thin out new shoots emerging from the old stem. Keep the soil moist during the period after severe pruning. The most common diseases on azaleas in South Carolina include petal blight, leaf gall, leaf spots, dieback, and root and crown rot.

The most common insects are lacebug and spider mites. Good cultural practices such as careful plant location, provision of good aeration and drainage, mulching and good watering habits will reduce the incidence of disease and insect damage. Iron is essential for healthy azaleas. Iron is available for uptake by azaleas when the soil pH is low acidic.

When soil pH is too high alkaline , iron becomes unavailable and chlorosis, or yellowing of the youngest leaves, may occur. A telltale sign of iron chlorosis is when the area between the veins is yellow or light green, while the veins are darker green.

Application of iron as a foliage spray will usually give quick, temporary results when applied during the growing season. In low pH soils, such as the clay soils in the Piedmont area, iron is readily available.

In these soils, chlorosis is usually due to other causes, such as waterlogged or compacted soil, root rot, or injury caused by nematodes or too much fertilizer. The first step to determine the cause of yellowing is a soil test to determine the soil pH. Azaleas are susceptible to cold injury, especially when exposed directly to early morning sun after a hard freeze.

The rapid thawing of frozen branches and twigs may result in bark splitting. Sudden early freezes in the fall and late freezes in the spring also cause bark-splitting. It may take several months before the branches die back on winter-injured azaleas with split bark. Prune out affected branches. To reduce chances of bark-splitting, plant only azalea varieties known to be hardy in your area. This information is supplied with the understanding that no discrimination is intended and no endorsement of brand names or registered trademarks by the Clemson University Cooperative Extension Service is implied, nor is any discrimination intended by the exclusion of products or manufacturers not named.

All recommendations are for South Carolina conditions and may not apply to other areas.