September 10, 2007
by Jennifer KinionThe cosmos are growing leggy and ragged, and many of the summer annuals and spring-blooming perennials are fading fast. Autumn is hot on the heels of summer, yet here in Marin we can expect to enjoy several more weeks’ worth of backyard relaxation before the chilly fall weather chases us indoors. As we make the most of our Northern California weather, it is only natural for us to want get the most out of our gardens. Our outdoor living spaces should beckon visitors with open arms and cheery color.If your borders and beds aren’t giving you that come hither look, there are lots of no fuss perennials, annuals and shrubs to choose from for a late summer, leap-into-fall color boost. Plant one or more of these now for long-lasting blooms that stand up to the heat:Pincushion Flower (Scabiosa atropurpurea)The dainty, half-globe shaped flowers of Scabiosa seem to defy gravity as they float above long, slender stems. Pincushion flower is an annual, but here in Marin, treat it as a perennial, cutting it back in late fall and top dressing with compost a few times each year. Scabiosa grows up to 3 feet tall and with diligent deadheading, will keep blooming for the long haul, all the while attracting bees and butterflies to your garden. Cut stems add interest to late-summer floral arrangements. Harvest the deep crimson, scarlet, lavender-blue, salmon, or white blooms just as they are starting to open. Pincushions are moderate water users and may require some staking to keep them upright.Sage (Salvia)Not all of these aromatic, mint family plants bloom this time of year. Two to try for color in late summer and early autumn are Whorled Clary Sage (Salvia verticillata) with its profuse, lavender-shaded blooms on hairy foliage, and Autumn Sage (Salvia greggii). Autumn Sage is available in a variety of heights (1 to 4 feet tall) and colors ranging from lipstick red ('Desert Blaze') to pure white ('Alba'). Give these plants full sun and good drainage, and although they aren't water hogs, provide moderate water and a monthly, deep soaking during summer. Bees and hummingbirds love sages. If you fall in love with one, try propagating more from cuttings.Gloriosa Daisy/Black-Eyed Susan (Rudbeckia hirta)With cultivars sporting names like 'Prairie Sun,' 'Indian Summer,' and 'Goldilocks,' how can a gardener go wrong? The vibrant yellow, orange, and rust-colored flowers of these plants have the visual appeal of branching sunflowers. Like sunflowers, they’re also sun loving, tough, and easy for beginners. If you like a splash of gold in your cut flower displays, Rudbeckia is one late-summer plant you’ll want to make room for. Dig in some soil-enriching compost, water moderately, and enjoy the show.Mexican Marigold (Tagetes lemmonii)This aromatic, shrubby perennial grows up to 6 feet tall and bears brilliant, yellow flowers. The dainty, delicately notched leaves release a minty, lemony fragrance when you brush against them. Tagetes prefers full sun, but can take dappled shade. To limit reseeding and maintain the fullness of the foliage, prune Tagetes after it blooms. As a bonus, Mexican marigold does just fine with low water, and is a good choice for a well-behaved, no-fuss container plant.Yarrow (Achillea)These low maintenance, low water perennials provide great material for both fresh and dried flower arrangements. Yarrows have grayish to green leaves, most with a finely divided, fern-like appearance. Flowers are borne in flat clusters atop a long, sturdy stem. Achillea filipendulina, or Fernleaf Yarrow, is a 4 to 5 foot tall species with green foliage and large flower heads. Achillea millefolium grows approximately 3 feet tall and is available in cream, bright pink, yellow, and red hues. Pair it with a red-streaked phormium or red hot poker for some visual appeal.Garden Verbena (V. x hybrida)These fast-growing, heat-loving workhorses of summer bear clusters of tube-shaped flowers in a variety of colors. ‘Aztec White Magic’ and ‘Aztec Cherry Red’ both grow about 18 inches tall and equally wide, making them good choices for containers, window boxes, or companions to taller perennials, shrubs and grasses.Have some fun with color combinations as you pick and choose from the plants on this list. Either a pale blue salvia or a yellow Mexican marigold would team up nicely with the deep red of Pennisetum setaceum ‘Rubrum,’ an ornamental grass that seems to be exploding into bloom in gardens all over Marin right now.
For all of the plants and varieties described, deadheading is the best way to ensure continuous blooms into (and even all the way through) autumn. Make it a point to patrol your garden, pruners in hand, a couple of times each week to remove spent and fading flowers.