Neil Sperry

Neil Sperry: Difficult spots in gardening

Coleus is a colorful shade annual.
Coleus is a colorful shade annual. Special to the Star-Telegram

It’s those funky little spaces that drive a gardener crazy. Conditions just aren’t quite right for any type of landscaping plant — or so it seems. We’re going to look one of them squarely in the eye here today, and it’s going to blink before we do.

Help is on the way for those little, narrow spaces that are in shade most of the day, then get hit by the laserlike summertime sun for three or four hours each day. It’s like pouring boiling water on an icy windshield. Something’s going to give, and it probably won’t be pretty.

Those extremes of full shade turning to blazing sun have lots of root causes. There may be a canyon of light that shines down in a shaft as the sun passes overhead between buildings. It could be the position of a major shade tree that lets sun bank into the west wall of a house late in the day. Or it could be a narrow bed along a fence, where the angle of the fence placement causes the planting to go from full shade into full sun in a matter of minutes.

Anyway, you get the picture. It’s coming out of a dark place into the noonday sun. Tough on your eyes. Tough on your plants.

Here are some things you can do to try to find a solution, so that your plantings can not only survive, but perhaps even thrive.

• First and foremost, avoid all plants that are listed as “needing full shade.” That’s not the environment for wimps like hostas, hydrangeas and aucubas.

• Avoid plants that use excessive amounts of water. That’s going to rule out several of our large-leafed plants like fatsias and oakleaf hydrangeas. It’s also a prime reason not to plant Japanese maples in those alternating sunny/shady places.

• Stay away from white gravel and other reflective mulches that bounce even more light back at the plants. And probably avoid black mulches as well. They soak up the sun’s heat, and that’s not good for the plants you are growing there.

• Be sure the area is properly irrigated. If it’s a long, narrow space, a drip irrigation line may very well be in order. These plants need extra TLC, and that little extra boost of water may be a huge help.

• Give the plants the best possible soil mix. This is a time for what I’d call “heroic” bed preparation. Rototill 10 or 12 inches deep, blending in 2 inches of sphagnum peat moss and 1 inch each of compost, rotted manure, finely ground pine bark mulch and expanded shale. You’ll have a soil mix that’s almost like potting soil. That will be a huge help to your plants.

• Buy plants that have been grown and held in conditions similar to what you’ll be giving them when they’re planted. That’s called buying “acclimated” plants.

• Consider using a sun-and-shade-tolerant ground cover such as Asian jasmine or purple wintercreeper euonymus, then putting steppingstones in place randomly within it. You could then position attractive terra-cotta or glazed ceramic pots atop the stones. That would make color change-outs quick and easy as the seasons progressed.

• Best shrubs for this kind of extreme solar situation include hollies, nandinas, abelias and boxwood. Plant them now, before the sunlight becomes any more intense, and be prepared to water them by hand for their first couple of years. They won’t be able to cope with sprinkler irrigation alone.

• Some of the annual color plants that would have the best chance of surviving the extremes would be sun-tolerant coleus, wax begonias, Dragon Wing begonias, pentas, angelonias, fanflower and perhaps crotons. Note that pansies and violas could possibly work well in this setting if the sun’s angle shifts enough with the season or if large trees are casting the shade in the summer. It may be that they could get enough sunlight to prosper during the winter.

• Perennials may be more of a challenge. It’s not because they can’t handle adversity, but more because there’s a thin line between adequate sun that would allow them to bloom normally and, at the other extreme, sunlight that would be inadequate for normal growth and plant development, let alone flowering.

Spring- and fall-flowering bulbs work great. Daffodils and grape hyacinths do their growing in winter, then bloom before the trees leaf out in spring. Fall crocus, spider lilies, oxblood lilies and Naked Lady lycoris produce leaves from late winter into mid-spring. Then, as trees start to leaf out, their leaves are drying. The bulbs become hidden during the summer, until the flowers emerge in August and September.

We promised you no magic solution to this ongoing shade-to-sun challenge for gardeners, but at least you now have several viable alternatives. Hope they help!

Neil Sperry publishes Gardens magazine and hosts “Texas Gardening” from 8 to 10 a.m. Sundays on WBAP/820 AM. Reach him during those hours at 800-288-9227. Online: http://neilsperry.com.

  Comments