I am always delighted when I come across plants which are new to me and are extra hardy, this is because I grew up in a much colder place. Many species will not live in a place that regularly visits temperature below -25 c. (-13 f.). It is particularly cum with interesting to find shrubs which are have colorful large flowers which bloom very early in the year and are not damaged by frost. One species which has been worked on to create more cold tolerant plants is the rhododendron. One of the important species which has been long known and is important in developing hardier hybrids with attractive flowers is Rhododenron dauricum (Dahurian Rhododendron) It has brightly colored flowered at this time of the year and is one of the toughest of the species.
Rhododendron dauricum comes form a fairly wide area of northern Asia. Its path begins in the Altai mountains of eastern Siberia and moves east all the way to the Sakalin Island and into Hokkaido – the most northern main Japanese island. The species is found in Mongolia, northern China and in through North and South Korea as well. As the plant covers such a wide area there is some variability in color and form which has added some confusion in classification. Linnaeus first described this Rhododendron in 1753 in his text Species Plantarium. He got his specimen from the botanical garden in St Petersburg Russia. It is possible that the sample had been collected by Messerschmidt in 1736 and already described by Johann Amman in 1739.
Rhododendron growers are always trying to broaden the range of their plants in many ways such as broader colro range, larger flowers, hardiness and bloom time. Rhododendron has played an important roll in making the species more avaialbel to those living in colder climate. Rhododendron dauricum is often used as pollen parent with other species to add cold hardiness to the hoped for hybrids. Probalby the most famous hybrid is called ‘PJM’(PJ Mezitt’) and is a mid pink color, it has smaller leaves which densely clads which slowly grows to about 2m.(6ft.). It was developed at Weston Nursery in Massetussets by Peter John Mezitt (PJM). He crossed dauricum with Rhododendron minus to creat this grest new plant. Other selection were also made but have not become so famous.
Rhododendron dauricum is classified as being semi-evergreen which is why most of the leaves are not seen in the winter,and the flowers are even more noticeable when they are in bloom. Here most winters the plants do look barren except for a few leaves and the buds which is tidy in appearance. This plant has smaller leaves and fairly fine stems and has an open airy quality about it. Most of the plants I have seen around here are still fairly young and many are taller than wide at the moment.
Rhododendrons are fairly easy to grow and this species is also easy. Rhododendron dauricum likes acidic moist soil which is well drained. Best placement is in part or dappled shade with some protection from bright summers sun and drying winds. I have seen these plants grow in quite deep shade and still put on a grest floral display at this time of the year.These plants can be used in a variety of ways such as massed, as an accent or specimen in a winter garden or in woodland settings. The floral color will draw your eye to wherever you choose to grow this plant.
Dahurian Rhododendrons grow to a fairly large 2m.(6ft.) by the same width. Rhododendron dauricum is rated as being zone 3b or -37c.(-35f.). They are rated as H4 or the hardiest of Rhododendrons. I have read notes from central Alberta to Newfoundland of how well these plants grow in the extreme conditions of different parts of Canada. If you live in a colder area this is one plant you must try to find, I am sure with a little attention this plant will give you years of pleasure.
Some Dahurian links for you:
Where is Dauria:http://en.wikipedia.org/wiki/Transbaikal
An article about Dauricum hybrids which are grown here:http://www.rosebay.org/chapterweb/specdaur.htm
A technical description of the plant is here: http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200016392
Information about the PJM group of Rhododendrons: http://www.hort.uconn.edu/plants/r/rhopjm/rhopjm1.html
……..Hope you wander this way soon……