August is a difficult month in the garden!
Written for the Davis Enterprise, July 26, 2001
The Dog Days of August....
Romans, with good reason, called it "the month of weeds." Hot, dry, dusty....August can be a difficult month in the garden! The spring and early summer perennials have peaked, and it's too early for the fall flowers. There's too much summer squash, and you're beginning to wonder why you planted a dozen tomato plants....Squeeze in a few last days of vacation because the kids are back in school before Labor Day. We want easy color in the garden, plants that love heat and bloom without special attention until cooler fall weather. We want bright colors that grab our attention as we rush by on the way to the pool....or perhaps that we can admire from a lawn chair in the shade across the yard!
So what blooms in August?
Two trees are the stars of the summer:
Crepe myrtle (Lagerstroemia hybrids) and Rose of Sharon (Hibiscus syriacus varieties). Both are incredibly tough and can be grown as shrubs or trees, basking in blazing hot sun and blooming from June until September.
... are small to large shrubs that can be trained as single- or multi-trunked trees, all with vivid, almost neon, colors. Modern hybrid crepe myrtles (L. indica x faueri hybrids) are better than the old varieties of L. indica, having more vigorous growth habit and greater mildew resistance (some are immune).
There are very miniature varieties: 'Pokomoke' (deep rose pink) and 'Chickasaw' (pink-lavender) won't exceed 2' in 6 years. Some are good-sized trees: 'Dynamite' (cherry red) and 'Natchez' (pure white) will both exceed 30'. And there are dozens of varieties in between, in all shades of pink, lavender to purple, white, and a few that are so dark pink they are called red.
The modern hybrids can be grown in lawns, but crepe myrtles are also drought tolerant. All crepe myrtles can be pruned for size control and will still bloom well, because they flower terminally (ie., at the end of each shoot) on new growth.
... is also naturally a shrub which can be trained as a tree. They have flowers like the familiar tender, tropical Hibiscus, but are hardy enough to grow in very cold climates. Flowers come in pure white, white with a red throat, and shades of pink and magenta.
Late summer is when the subtropical plants really come into their greatest seasonal display. These are plants that freeze back in a normal winter and might even be killed if it's unusually cold, but which flourish in our summer heat. Most subtropical require no special attention in the summer, blooming for as long as the weather stays warm.
Bougainvilleas are on the tender end of the spectrum, but worth coddling in the winter for their intense, vivid summer hues. Cape plumbago (Plumbago capensis) flowers are a clear, sky blue color on a plant that sprawls or clambers up onto a fence or other nearby shrubs. Lantana hybrids come in hot colors of orange, red, yellow, and pink; the trailing forms come in purple, white, and yellow.
There are several easy subtropicals for the shade.
Brazilian plume flower (Justicia carnea; formerly Jacobinia carnea) has dramatic spikes of pink flowers. Flowering maples (Abutilon hybrids) have hibiscus-like flowers in yellow, orange, red, pink, or white. Fuchsias are very easy to grow in large pots or in soil that has been enriched with planting mix, and come in shades of red, blue, pink, and white. All of these shade perennials attract hummingbirds. You can expect frost to kill all or part of the tops of these plants, but they will usually resprout in April.
...are generally pretty carefree, but without some grooming there can be a gap in blooms in August as the spring and early summer perennials seem to stop. Many of these will initiate new flowers if they are "dead-headed," a charming term for removing the spent blossoms to prevent them from setting seed (when a plant sets seed it "thinks" it has done what nature intended, so we have to fool it to keep it flowering!). Penstemons and Shasta daisies are good examples of plants that will continue to bloom if they are dead-headed.
Some hardy perennials naturally bloom in late summer, filling that August gap. Dwarf plumbago (Ceratostigma plumbaginoides) has vivid, dark blue flowers on a plant that creeps steadily by rhizomes, forming a ground cover. Purple coneflower (Echinacea purpurea) has dramatic magenta daisies from August to mid-September (there is also a white form). Both will grow in full sun or partial shade. For full, hot sun the Black-eyed Susan (Rudbeckia hirta; also called Gloriosa Daisy) has dramatic daisy flowers in yellow, orange, or mahogany.
... are old favorites from years ago that are enjoying a resurgence in popularity as breeders keep introducing varieties with greater color range and more compact growth habits. These are small daisy flowers resembling single Chrysanthemums in shades of pink, magenta, rose, lavender, and blue, most with a dramatic yellow "eye" (center). Very easy to grow in sun or light shade, they spread steadily but slowly--some of our ten-year-old plantings are 4- 5' across. Most bloom from August through September, and the taller forms make great cut flowers.
...Sages are a very diverse group of summer and fall blooming shrubs and perennials. Some die to the ground each winter (but resprout in the spring) while others form woody shrubs. Most have vivid flowers in shades of pink, red, purple, or true blue, and all attract hummingbirds. A few prefer shade and regular watering, but most will take hot direct sun and considerable drought. Salvias are becoming more popular--the new Sunset Western Garden Book lists six pages of species and varieties!--and are especially appropriate to our dry climate.
Finally, a last planting of heat-loving summer annuals can give you a mass of color from August to October. From A to Z: Sweet Alyssum, Celosia, Cosmos, bedding Dahlias, Dianthus, Lobelia, annual Salvias, Verbena, Vinca, and Zinnias are all easy summer annuals that bloom freely in full sun until the nights get cool; Begonias and Impatiens will bloom in part sun or shade.
© 2008 Don Shor, Redwood Barn Nursery, Inc., 1607 Fifth Street, Davis, Ca 95616
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