Brilliant hued leaves announce the arrival of autumn almost everywhere you look this month.
For sure, trees are the stars of this seasonal show. Along roadways, our eyes are riveted to the wide spectrum of changing leaf pigments – from greens to golds, reds to purples. During walks, I pause to tuck leaves into a pocket and secretly wish for yard space to contain a forest of such colorful mature trees.
Yet for more than 1,200 years, people have invited fall color into their lives and enjoyed the changing seasons around their dwellings by planting trees in containers. Renown for its foliage, the slow-growing Japanese maples (Acer palmatum) is a popular pick featuring striking branch patterns and different leaf shapes in a variety of textures. With numerous cultivars to choose from that fit well in either a pot or a plot, you and I can also cultivate the beauty and ambiance of a mature tree however small our space. The most important consideration is matching the maple to a location.
Japanese maples produce small red or purple flowers and winged fruit I label “miniature helicopters” that twist and turn as they spiral toward the ground. The leaves feature five to nine palmate lobes –some wide, while others are finely dissected and threadlike. Branch patterns vary from round to vase or weeping. Height ranges from the dwarfs (developed for bonsai) that reach maturity at under 6 feet to trees that grow 15 to 30 feet tall. Japanese maples are separated into two groups:
Often called “understory trees” in their native habitat of Asia, Japanese maples flourish best in the afternoon shade of buildings or under the filtered canopy of tall trees. Although most maples are moderately drought-tolerant, they are thin-barked and easily scald in the sun, especially recently transplanted younger trees that are still establishing roots. Some sun is necessary to trigger pigmentation, but too much can bake roots and burn leaf tips.
Red-leaved and variegated varieties do not tolerate direct sun as well as green-leaved cultivars. Wind is also a stressor that fries leaves and dries the soil. This past summer in Solano County’s warmer sections, weeks of hot temperatures turned many Japanese maple leaves prematurely brown and/or disrupted the pigmentation process, especially if they were under-watered.
Choose a container that is no larger than twice the diameter of the root ball and half the depth of the roots. Japanese maples prefer well-drained slightly acidic soil but can tolerate alkaline soil. During the summer, an application of loose mulch provides protection from sun damage and help retain moisture. However, keep mulch away from the tree’s trunk to avoid root rot, especially in rainy weather.
Placing the container atop a wheeled platform offers you flexibility to roll your maple tree to different locations until you find just the right spot for it to thrive.
Whatever variety of Japanese maple that you pick to plant, the color choices are endless. Do you like chartreuse and amber leaves, or magenta, scarlet, or maroon? How about rosy or salmon pink or mauve? Maybe crimson, soft creamy yellow, milk chocolate, purple brown – or what about an orange that’s fiery or one that’s rusty? Do you want your tree with green bark or black bark – or coral? Even leaf veins vary from red to black to brown.
Whatever your preference, you can’t go wrong when you invite home the spectacular fall color of a compact, slow-growing fit-for-a-container Japanese maple.
Launa Herrmann is a Master Gardener with the University of California Cooperative Extension office in Fairfield. If you have gardening questions, call the Master Gardeners office at 784-1322.