Acid-loving plants are widely available. Some nurseries specialize in the raising of such plants, particularly rhododendrons and heathers. Most young plants will be containerized in a special acid compost.
The same rules for choosing acid-loving plants, particularly shrubs, including rhododendrons and heathers, apply as to the selection of other subjects . Choose healthy-looking specimens, as ericaceous plants soon begin to reflect poor maintenance in loss of condition, particularly with yellowing leaves which are a sign of lime-induced chlorosis, possibly owing to watering with hard water, or potting on into the wrong compost.
What to buy. This is mainly a matter of personal preference. The term ‘acid gardens’ is a very loose one, only describing the type of soil found in such an environment, although it conjures up pictures of heather beds, rhododendron collections, azalea borders and the like, but there is nothing to stop one making a mixed shrubbery in such an area, or even a mixed border, using acid-loving herbaceous plants as well. In fact, many lime-tolerant plants will grow just as happily in acid soils, although if you have gone to considerable labour and expense in creating these conditions, it seems rather a waste to occupy space with plants which would be perfectly contented elsewhere in the garden, unless there is something which is essential to the overall effect — e.g., ornamental conifers in a heather bed.
Many rhododendrons are now raised by micropropagation, resulting in sturdier, healthier plants which flower earlier and better.
As the only important thing which distinguishes acid-loving plants from others is their inability to tolerate lime, all the general rules for planting –times, methods, etc., still apply, although many ericaceous subjects originated in impoverished soils and therefore require less feeding than the majority of plants. A good rule of thumb for feeding is to give about half the amount you would to a similar lime-tolerant plant. Rhododendrons, azaleas and many other acid plants are surface rooting and should never be planted any deeper than they were in the nursery, but heathers can be planted slightly deeper.
Regular mulching with bark, cocoa shell or leaf mould helps to conserve natural moisture and keep the pH low. Pruning is more a matter of the type of plant in question rather than the fact of whether it is or is not lime-tolerant, so the general principles of pruning apply.
Heathers can be just clipped over with shears after flowering to keep them compact and bushy. Rhododendrons and azaleas should never receive regular pruning other than the removal of dead or diseased wood and badly-placed branches, but should have the dead flower-heads only (not the wood underneath them, which contains next year’s flower buds) removed. Very overgrown bushes, however, will regenerate if cut hard back.
Feeding is not really necessary on a routine basis. When it is needed, the rough rule of half the recommended dose will usually be enough. If you find growth is poor and the plant looks generally yellow and unhealthy, it is a sign that too much lime is getting to the plants, either through tap water or leaching from the surrounding soil (the latter is unusual, though). This can be corrected with sequestrene as already described. If you live in a very alkaline area, give an application of sequestrene annually in spring as a matter of course.