Allz you ever wanted to know about Rhododendrons

Species name: Rhododendron sp. (perhaps a cultivar or variety of R. wardii but I'm not positive)

Common name: rhododendron

Location: Sandra's garden

Rhododendrons are really gaining popularity in North America as garden plants, especially those species that are native to this continent. Most gardeners aren't actually aware that we have many native North American species of rhododendron, since the most widely available and easiest to grow are those native to China (like this one probably is), Japan, Korea and Taiwan. Rhododendrons prefer acidic soil which is most commonly found under very old coniferous trees. So if you have some pruned firs, spruces or pines (so that the lowest branches are several feet off the ground and the base of the tree receives a fair bit of sunlight) and want to plant something under them, rhododendrons would be a good bet! Just make sure they will receive enough sunlight; they do best in full sun. Make sure you take care in paying attention to what species you're planting and where you live; various species of rhododendrons can be highly invasive in locations where they are not native.

If you grow your own honey, which is also gaining in popularity with gardeners with large yards since bee populations are on the decline, it is strongly suggested that you do so only when your bees wouldn't have ready access to rhododendrons (and other species in the same genus that we call azaleas because the flowers only have five anthers instead of the usual ten; you can read my previous blog about azaleas HERE). The pollen and nectar of rhododendons contains a toxin called grayanotoxin, which can cause hallucinogenic and laxative effects. Not exactly the kind of thing you're expecting when you consume honey! Horses have an even more extreme reaction to grayanotoxin: it can cause seizures and even death. Thankfully for horses, they usually avoid rhododendons based on the smell alone and would rather look for something else to eat. Cats and dogs also have adverse effects to rhododendrons, but the effect is much more pronounced in dogs than in cats (are cats smarter for staying away from the plant more often? Perhaps. Is this my bias for what pet I prefer more? Perhaps...). Dogs like to chew on sticks, so if you prune this plant and leave the sticks laying around your beloved pet might be in for a surprise. Symptoms include digestive issues, heart palpitations, heart attack, and liver failure. Eventually these symptoms will lead to death if the animal is left untreated. Supervise your pets around your landscape plants!

Rhododendron species are very important to different cultures around the world. For example, different species of rhododendron are the national flower of Nepal, the state flower of both Indian-administered and Pakistan-controlled Kashmir, the state tree of Sikkim and Uttarakhand in India, and the state flower of West Virginia, Pennsylvania, and Washington in the United States. Not bad for a plant!

Allz you ever wanted to know about Azaleas

Species name: Rhododendron sp.

Common name: "Northern Hi-lights" azalea, Northern Hi-lights rhododendron

Location: Ontario

Surprisingly enough, many of the species of plants in this genus are actually native to North America. Usually when you think of (OK, maybe you don't but I do) bright, showy flowers you think of Asia and sometimes South America. I rarely think of native plants as being bright and showy. Azaleas can be the one exception: many of the deciduous species (there are species in the genus that are either deciduous or evergreen) are cold-tolerant, and many will also tolerate below-optimal nutrients. I'm going to give this plant the benefit of the doubt and say it's a native species. This particular cultivar (meaning, it was created through "artificial selection" or selection through plant breeding) was created at the University of Minnesota through plant hybridization in 1994. Because it's a hybrid it is not true to seed, meaning it either doesn't produce seed (which I've never seen this plant produce any, so this is probably true) or the seeds produced are sterile. There is another condition when plants are referred to as not being true to seed; this is when the plant that grows out of the seed is not even remotely the same as the plant from which the seeds came. This happens through genetic recombination (or "gene shuffling") during mating, and there are many fruit tree species that are great examples of this phenomenon. If you've ever tried planting an apple seed and taking care of the tree to fruiting you'll have experienced this first hand!

Many species of azalea are tolerant to partial shade, but this cultivar apparently isn't one of them. This is a shame, since it's currently planted in my back yard under the stairs leading up to the deck and only gets sun for maybe an hour a day during the summer. If the landscapers had of planted it in a sunnier location, it would be loaded with flowers every summer and bring in quite an interesting array of wildlife into the back yard; I've heard that the flowers of this plant have much the same effect on racoons as catnip does on cats! Potentially entertaining, to say the least.

A cautionary tale with azaleas of any species is to make sure you supervise young children and pets around this plant, since all parts of (almost) all species are toxic. The toxic effects will be unlikely to lead to death in humans (it might in animals), but a sick child makes a very unhappy parent! Even honey from rhododendron flowers is said to be mildly hallucinogenic and is a mild laxative. That being said, this plant does have some potential as a source of medicine: it has been found in the lab to have anti-inflammatory effects and hepatoprotective effects (protects your liver) and so extracts from this plant are currently being investigated as a potential treatment and/or cure for liver disease.