Rhododendrons can be deciduous or evergreen, although many of the most popular varieties for the garden tend to be evergreen. Rhododendrons are undemanding and easy to grow shrubs, their only essential requirement is an acid soil which is a soil in which the pH is 7.0 or below. As the images above show Rhododendron flowers are lovely showy blooms and attractive to bees as a good source of nectar. In gardens with acid soil, it is easy to grow Rhododendrons and Azaleas as they will thrive on ericaceous soil, but they will not grow well in alkaline soil so it is best to check first. This is not just a case of growing better in acid soil, Rhododendrons simply will not grow in any soil other than acid soil. Generally Rhododendrons flower from March-May.
It is easy to be put off Rhododendrons, which in recent years have had a bad press, as being a very large shrub swamping other plants. It is correct that the common Rhododendron, common rhododendron or pontic rhododendron, is considered a menace, and which looks like the image above right. In the wild in the UK this variety of Rhododendron is invasive, out competes native plants and is to be avoided.
However, Rhododendrons are a vast group of genus over 900 in all shapes, sizes, and heights which means there is a suitable shrub for all types of gardens from low growing compact varieties to huge tree like shrubs. Rhododendrons come in a wide colour range, pink, purple, yellow, white, red and orange, just about everything. The colours are bright and bold; a Rhododendron in full bloom is eye catching. Rhododendrons need no real attention other than an acid soil, although most prefer dappled shade. Rhododendrons are originally a woodland plant and so dappled shade is their native conditions, although Rhododendrons are fairly tough and will grow anywhere in the right (acid) soil. If the growing position is very sunny the smaller compact and deciduous varieties will do best.
It is because Rhododendrons are such a wide genus with many varieties it is important to check the plant label when buying to check the eventual size, as some are get very large and be thuggish. There are many on the market which are compact, and it is well worth checking the label, to make sure the plant is suitable for the space in your garden as some are huge, small trees really.
If you are thinking of growing Rhododendrons, but unsure of your soil type, you can do one of two things. You can buy a soil kit to test the Phd of your soil which will tell you if it is acidic: a result of pH 7 below is acid soil, pH7 neutral and pH7+ alkaline soil. Alternately you can check out your neighbour's garden and see what's growing there. If there are Rhododendrons and Azaleas in the neighbourhood, the chances are your soil will be similar.