Gardening in the Twilight Zone

August 30th, 2007

   Hold tight, gardeners, you are about to enter… The Twilight Zone.

   Only this Twilight Zone isn’t so much a freaky collection of bizarre happenings as it is a dead zone where not much is going on.

   Late summer in the garden is that time when most plants have peaked but before fall foliage brings us one last blast of glory.

   It’s a time when the annual flowers are petering out.

   It’s when most of the flowering shrubs have bloomed.

   It’s when bug and disease attacks have left holes in the roses, rusty streaks on the daylilies and strange little brown sacks all over the browning arborvitae.

   And the vegetable garden? Can you even see it anymore?

   In another six weeks or so, the landscape will resurrect with scarlet maple leaves, neon-red holly berries and russet ornamental grasses before frost pulls the plug on our fun.

   But in the meantime, a lot of yards look more like black holes than twilight zones.

   That’s especially true in yards where the plant variety is limited.

   That happens because most people plant-shop in May when the gardening hormones kick in. And that means yards get loaded up with things that look good then, such as azaleas, rhododendrons, lilacs, dogwoods, peonies and maybe a weigela or two.

   It’s no wonder.

   A homely little beautyberry bush that won’t produce its stunning sprays of metallic lavender berries until September is no match in May for an azalea’s bright rosy-red big-bang-ball of color.

   A bag of shriveled brown hockey pucks called “dahlias” can’t compete with the fist-sized blooms of a peony plant.

   And crape myrtles haven’t even leafed out yet in early May while the dogwood blooms are more alluring than a doughnut shop to a dieter.

   It’s unfair competition, that’s what.

   If beautyberries had antitrust lawyers, they’d no doubt sue.

   One way to brighten the dog days is to plant more variety. If you plant enough different things, you’re bound to end up with at least a few plants that look decent down the home stretch.

   Plant-shopping at this time of year — at the beginning of fall planting season — is another good way to turn the tables on the competition.

   This is when the dahlias look great and the peonies are looking ratty. It’s when the crape myrtles are in glorious bloom and the dogwoods are dropping leaves from anthracnose and powdery mildew.

   A third strategy is planning for home-stretch interest no matter when you buy.

   When you stop and think about it, there’s actually a lot of potential beauty to tap in these next six weeks. The choices fall into five categories:

   1.) Plants that peak during The Twilight Zone. Some plants are naturally late to show off their stuff. Best known is mums, but sedum, asters and goldenrod are three other perennial flowers that bloom late summer into fall.

   Two lesser-knowns worth considering are leadwort (a.k.a. hardy plumbago), which is a low, spreading groundcover that blooms cobalt blue this time of year and then gets glossy scarlet leaves in fall, and Mexican bush sage, a type of tender salvia that sends up a forest of late-season purple spikes.

Sweet Autumn Clematis.

   In the woody world, the sweet autumn clematis is a vigorous vine with clouds of white in September, and the blue mist shrub (Caryopteris) is one of the latest-blooming shrubs, flowering in powdery blue or blue-purple on a 3- to 4-foot silver-leafed ball.

   Other late-peakers: dahlias, Japanese anemone, liriope, turtlehead, helianthus, tricyrtis, boltonia, “naked ladies” (Lycoris).

   2.) Plants that rebloom at this time of year. Especially if you’ve cut back or removed spent flowers earlier, many plants will rebloom in The Twilight Zone.

   Roses are an ideal example of a plant that mainly blooms in June but that gives a smaller second show in September. Catmint, yarrow, salvia and hardy geraniums are four perennial flowers adept at second winds.

   Breeders also have been giving us new varieties of old favorites that have been found to rebloom. The ‘Endless Summer’ reblooming hydrangea has been the most hyped example (mine were blooming into late November last year), but we also now have a nice selection of reblooming daylilies and iris.

   Other home-stretch rebloomers: Butterfly bush, gaillardia, spiderwort, beebalm, coreopsis, scabiosa.

   3.) Plants with great late-summer and early-fall fruits. Fruits and berries add a whole new color dimension from here on out. The aforementioned beautyberry is the best of the little-known examples, but we’ve also got red and gold berries from both evergreen and winterberry hollies, orange berries of pyracantha and a whole host of berry colors on various viburnums.

   Other home-stretch fruiters: Kousa and American dogwoods, hawthorn, cotoneaster, inkberry holly, yew, Japanese plum yew, juniper, nandina, Oregon grape holly, chokeberry, St. Johnswort, ornamental hot peppers and some roses.

   4.) Plants with colorful foliage all season. Some plants are grown mainly for their colorful leaves that stick around until frost turns them to mush.

   These would include dark-leafers such as coralbells, red barberries and the new ‘Diabolo’ ninebark; golden-foliage plants such as golden Hinoki cypress, golden junipers and golden oregano, and variegated plants such as variegated weigela, variegated liriope and several varieties of euphorbia. 

Elderberry 'Black Lace'

   Other colorful-leafed beauties: Foamybells, ligularia ‘Britt-Marie Crawford,’ dark-leafed cimicifuga, Japanese maple, purple beech, purple or gold smokebushes, purple or gold redbuds, blue spruce, goldthread falsecypress, golden spirea, abelia ‘Kaleidoscope,’ elderberry ‘Black Lace,’ forsythia ‘Kumson,’ blue-tinted fothergilla, variegated hydrangea, variegated red-twig dogwood, purple and gold St. Johnsworts, variegated brunnera, Japanese painted fern, pulmonaria, golden yucca, some ornamental grasses.

   5.) Plants with endurance. These are long bloomers that don’t know when to quit. They start blooming in summer and keep going, and going and going.

   A lot of annual flowers fall into this category. So do a few energetic shrubs such as ‘Knock Out’ shrub roses, crape myrtles, tree-type hydrangeas and butterfly bushes.

   But most are perennial flowers, including: Lamium, agastache, verbascum, vernonia, gaura, hardy hibiscus, phlox, heliopsis, Russian sage, black-eyed susans, eupatorium.

   Now you’ve got some ammunition. And no excuse not to light up that black hole in your yard.