In May you will certainly notice one of the most admired plants, a large shrub covered with large, almost tropical looking flowers. This is the Rhododendron, a shrub that is represented in both high alpine and lowland tropics, from the Sino Himalaya to tropical forests to the Alps, and with many varieties to grace our gardens and provide year-round interest.
The Rhododendron ranges from six inches to 60 feet, although in our climate it would not get nearly that tall. Its advantages are many; it is evergreen, it is deer proof, and the multitude of varieties ensure there is something for both shade and sun. Its only strong dislikes are wet boggy soils, and being placed directly in the path of wind. A well drained but moisture retentive soil will give it the required foothold and an annual mulching will ensure moisture retention. Rhododendrons have a fibrous root ball close to the soil surface, which makes them more prone to drying out.
Choosing a Rhododendron requires you to look at the aspect of your garden — which way does it face? Is it sheltered from prevailing winds and strong sun? The large leafed Rhodos would be a good choice. Plants that grow in shady areas, or under trees tend to have larger leaves to maximize the available leaf surface for collecting light. They enjoy semi-shaded conditions and still produce large exotic flowers that look like they belong to an equatorial island rather than the temperate forests of the northern hemisphere. They also associate well with our native flora. Cultivars can be chosen that also have distinctive foliage. While you can have Rhodos in bloom from January to August, the majority of them are in full cry during the months of April and May, and a plant with attractive foliage will add considerable interest to your garden.
Shade is not an absolute requirement. There are many varieties, generally dwarf, that prefer an open situation. These tend to originate from higher altitudes and usually have smaller aromatic leaves and flowers. They are quite hardy, blooming from March to April.
A good place to see and purchase different Rhododendrons this month is at the Cowichan Garden Fair, Saturday, April 29, 10 a.m.-2 p.m. at the Cowichan Exhibition Grounds. There is a truss show (the rhododendron flower) consisting of named cultivars that will be brought in to be displayed, and people will be on hand to answer questions. Hundreds of Rhodos and companion plants will be available from local growers at the fair. For more information, check out www.CowichanValleyGardenFair.com
Barrie Agar is the head gardner at Hatley Park National Historic Site/Roads University, and president of the Cowichan Valley Rhododendron Society.