Fall and Winter Color in Rhododendron Foliage
Having started a colored movie of rhododendrons and azaleas to illustrate the bloom sequence of the material grown at Lackamas Gardens, I decided that a few out of bloom season shots of color changes in the foliage of some of these plants would be interesting. Naturally this decision led me to a much closer observation than before. As autumn with it's crisp nights and sunny afternoons began to get in a few strokes with Nature's paint brush, I realized that here was a value that some of us, perhaps, had failed to fully appreciate.
Starting in September I began making the rounds of the planting, taking a few color shots here and there that looked especially interesting, continuing through the month of October and most of November. This film, processed and recently returned, exceeded my expectations to the point where I greatly regret not having taken more footage.
The deciduous species and azaleas naturally afford the best fall color. Other shrubs and- trees that usually make such a brilliant display were far below par this season due it is presumed to the lack of frost in this area. However the azalea foliage seemed to color as brilliantly as ever under this mild condition and held their leaves much longer. Even now, on December 2nd, we have occidentale in full leaf, growing in a northern exposure, a pure golden yellow.
These color changes, starting early in September, are extremely varied. Beginning with a bronze or chartreuse, according to variety and continuing through the various shades of yellow, orange, scarlet, red and maroon. Many individual plants passing through nearly all of these color phases. With the thought that it may be of assistance to those wishing to work out a fall color picture in their plantings, I shall note a few of my observations of certain plants that seem to possess unusual charm in this respect.
The different forms of A. schlippenbachii have one of the most extended seasons, passing through many fall color phases ending with deep scarlet. The bronze leaves of A. 'Altaclarense' vary slightly from flaming scarlet to wine red. Occidentale and true mollis seem to run to yellow shades and hold their fall foliage well. A. japonicum and its hybrids seem to run mostly to reds and starlets. Most of the Ghent and other imported hybrids I have observed have beautiful shades of red. The Lackamas occidentale x Ghent hybrids have brilliant colors shaded to pastels on the same leaves.
In the evergreen class, most of the Macrantha azaleas with their dimorphic leaves, though much smaller are very attractive for a considerable period before dropping their spring leaves, which take on various colors at this time. Many of the dwarf rhododendrons such as pemakoense have the same habit. Many of the japonicum series with their tiny leaves have the somewhat disconcerting habit of appearing to turn up their toes and pass out when cold weather really arrives. Their leaves arid twigs appear to be dying, taking on various bronze and purple hues. This habit has caused considerable worry by their owner when observed for the first time. However with the advent of the first warm spring days they regain their natural appearance and proceed to bloom and thrive merrily on.
I might observe here that many of the worries over the appearance of the different rhododendrons during certain seasons may be somewhat allayed if one will take the time to study the habits and background of the different species in question. This may also apply to many Hybrids where parentage is known.
The Azaleodendron 'Broughtonii Aureum' might serve as an example. Its leaves taking on beautiful bronze shades in normal winters often become completely deciduous under rigid cold spells without damage to the plants or flower buds. A considerable number of the Kurume azaleas, though being entirely evergreen undergo these color changes in winter and appear to advantage when planted against a light colored background.
The foliage color on the new growth of many evergreen rhododendrons are delightfully varied. Most of the species in the R. falconeri , R. grande , R. taliense and kindred Series make a wonderful showing while in new growth with their downy whites, buffs, and copper shades. The streamer-like red leaf bracts on the new growth stems of R. arizelum being especially attractive. These features, together with the varied leaf contour, size texture, and indumentum color largely compensate for their reluctance to produce bloom while young in these series. R. williamsianum as well as most of its hybrids seem to produce the same beautiful chocolate colored new growth. R. 'Moser's Maroon', as a seed parent crossed with R. griersonianum and its primary hybrids has produced many highly colored new growth features, a few as striking in color as the new growth on Pieris forrestii .
These notes have mentioned only a very few of the attractive features of rhododendron foliage. Close observation will reveal many other subtle values to us all as we become more acquainted with this noble genus.
It has been suggested that a colored movie, of the test gardens be made with readable signs or sound track descriptions of prominent features of the planting. It is thought that a project of this kind could be a wonderful asset to the A.R.S. in arousing interest in rhododendron culture. Distant Chapters of the Society would be able to see the progress of the test garden and one of the word's finest rhododendron collections. Doubtless many other horticultural organizations would be pleased to subscribe a small fee to the Society for a showing of such a film.
Perhaps a fund could be built up from among the members and others by subscription. No doubt it would be advisable to have this film supervised by one acquainted with rhododendrons who could make at least weekly calls to catch the various subjects at or near their prime. Perhaps this sounds like a dream, so was our test garden at one time. Remember that dreams combined with a certain amount of honest sweat are the essence of all great realities. What is your opinion concerning this?