Companion Plants: Trees for Fall Color
Aldergrove, British Columbia Canada
Reprinted from the Fraser South Chapter newsletter, Nov. 1992.
The ideal weather conditions for fall color are warm sunny days and cool nights. This allows the manufacture and accumulation of sugars in leaves which in turn are the basis for development of pigments associated with red coloration. In British Columbia we do not have a lot of native plant material like the beautiful sugar maples, and in many years our foggy, overcast weather limits the development of local fall color. That does not mean we have to live without the beautiful colors of this season.
There are many cultivated trees, shrubs and vines that can be grown locally that will provide fall color and add other features of seasonal interest to our gardens.
If you want to add new plant material to a garden for fall color, you should be visiting local garden centers now. Within any group of plants you will find a range of colors, and some plants may have more color than others. Also, when planting for fall color, remember that sunlight is a key to manufacture of pigments in plants, so, for best fall color, put plants in areas where they receive full sunlight. Some years you may find that color development is better than other years because of the weather conditions. A sunny fall with gradually cooling temperatures will provide for conditions for best leaf color displays.
The following are some of my favorite trees for providing fall color. These plants are all hardy in our area. Your local nursery can provide advice on planting procedures. I have tried to include some plants that are readily available, but all of the trees listed can be found locally with a bit of hunting.
We may not have sugar maples for fall color, but many of the small species of maple trees provide wonderful shades of yellow and scarlet. The amur river maple ( Acer ginnala ) is a small maple that develops brilliant red leaves. Some of the Japanese maples ( Acer palmatum and A. japonicum ) also offer fall color, although there can be great variability in color development from one tree to another with these two species.
The sourwood tree ( Oxydendrum arboreum ) has two desirable features. It is a late summer bloomer, bearing delicate sprays of small white flowers in August. Then in late September! the leaves change to a deep mahogany red. Sourwood is in the same plant family as rhododendrons and pieris and has the same kind of growing requirements. This plant needs good drainage and acid soils. Again, for the best fall color, it should be planted in full sun.
Another small tree that has gorgeous fall color is the Persian parrotia tree ( Parrotia persica ). This plant can be grown as a single-stemmed small tree or a multi-stemmed large shrub. It is related to witch hazel and, like some of our witch hazels, parrotia blooms in winter. The winter flower aspect is a nice bonus in the garden, although it does not start to produce many flowers until about 15 years old. Another feature of winter interest is parrotia's flaking bark, which produces mottles of white to gray. While adding to the winter landscape, parrotia is best known for fall color. The leaves change from dark green to yellow, deep orange and red. Again, full sun is absolutely necessary for good foliage displays.
For lovely golden yellow foliage two of my favorite trees are the gingko tree ( Ginkgo biloba ) and the katsura tree ( Cercidiphyllum japonicum ). In some years, the katsura tree may develop leaf colors into the orange and red tones, although the yellow leaf color is usual. Both trees have interesting leaf shapes throughout the summer. The ginkgo tree has a fan-shaped leaf, and the katsura tree has delicate, heart-shaped leaves. Both of these plants may be slow to establish, but they are definitely worth troubling over.
Our local Pacific dogwood ( Cornus nuttallii ) can have vivid orange-yellow fall color in seasons where we have good autumn sunshine. The leaves often change color intermittently, so we can have rich green leaves, mixed with orange and yellow all at once. In addition! there is also sporadic fall flower production with our native dogwood, which adds further interest to the landscape. Eddy's White Wonder', the hybrid between our Pacific dogwood and the eastern dogwood, does not flower in the fall, but it does have spectacular fall color.
Some of the oaks can have scarlet to deep mahogany red leaves in autumn. Pin oak ( Quercus palustris ) and scarlet oak ( Q. caccinea ) are two commonly available oak species that are valued for their fall color. Oaks are magnificent trees, but ultimately they are large, so only plant these if you have the room to let them grow.
Both the sweetgum tree ( Liquidambar ) and the tupelo or blackgum tree ( Nyssa sylvatica ) are also recommended for their scarlet leaf colors in autumn.