Xeriscape plans need raised beds to work in Houston
Q: Could you please tell me the name of some books which identify plants that can be used for xeriscape landscaping in Houston? It is preferred that the books have pictures of the plants and describe their characteristics. Marvin Jones, Houston
A: There are few books on xeriscaping that pertain to Houston, however, there are other useful sources that offer plant suggestions to conserve water in the landscape here.
Xeriscape recommendations vary by region, so it is important to choose plants that can make it in our area. A plant that thrives in a Hill Country xeriscape might not be suitable here.
While we have stretches of dry conditions, it can be really wet. In addition, our soils tend to be poorly draining heavy clay. To cope with extremes, it’s best to plant in raised beds filled with a well-draining soil. Add a little sharp, clean sand and compost to improve drainage. Such raised beds help ensure that plants, especially those that prefer drier conditions, do not sit in wet soil.
It’s also important to group plants in garden beds according to water needs — whether they can get by on just rainfall, need occasional help from irrigation or more regular watering when there’s no rain.
Native and EarthKind plants are your best low-water bets. There are other proven lowwater plants that, once established, require less care, too.
You may find ideas in “Xeriscape Gardening: Water Conservation for the American Landscape” (MacMillan, $30) by Connie Ellefson, Tom Stephens and Doug Welsh and “The Water-Saving Garden: How to Grow a Gorgeous Garden With a Lot Less Water” (Ten Speed Press, $19.99) by Pam Penick.
Two older books found in limited supply online are “The Dry Garden: A Practical Guide to Planning & Planting” (Sterling Publishing, $19.95) by Mark Rumary and “Taylor’s Guide to Water-Saving Gardening” (Houghton Mifflin, $16.95) by Norman Taylor.
There’s good information on the Texas A&M Unversity websites aggie-horticulture.tamu.edu and earthkind.tamu.edu, which has a great plant guide.
I compiled a list of low-water plants for a Houston-area landscape that include:
Trees: cedar, crape myrtle,
green ash, goldenrain tree, ‘Carolina Sapphire’ cypress, Mexican plum, Mexican redbud, oaks, sweetgum, Texas olive, Texas redbud and vitex.
Shrubs: abelia, American beautyberry, American holly, Barbados cherry, bird of paradise, calliandra, cherry laurel, duranta, eleagnus, esperanza, hamelia, Indian hawthorn, buddleia, mahonia, Japanese boxwood, juniper, mock orange, nandina, oleander, Japanese yew, rock rose, spirea, Texas mountain laurel, Texas sage, turk’s cap, wax myrtle, yaupon, yucca and the oldfashioned shrub called yesterday, today and tomorrow.
Ground covers: Asian jasmine, Gulf Coast muhly grass (taller but beautiful), hardy ice plant, ‘Katie’ ruellia, liriope, mondo grass, sedums and wedelia, which can get too happy.
Perennials: agave, artemesia, bouncing bet, butterfly weed, coreopsis, crocosmia (corm), cuphea, Dahlberg daisy, daylily, evening primrose, gazania daisy, lantana, liatris, narcissus (bulb), purple coneflower, gaillardia, lion’s tail (leonotis), Mexican petunia (ruellia), red hot poker, rudbeckia, Russian sage, a great list of ornamental grasses, penstemon, rosemary, salvias, verbena, winecup and yarrow.
Annuals: celosia, cleome, cosmos, gomphrena, periwinkle, purslane and zinnia.
Q: I have a flower bed that is full of tree roots. I have been thinking what I might put there in order for other plants to have room for roots. I have thought about those fabric bags that you can put soil in. Or a rectangular planter might work. I don’t think a raised bed, even with metal edging, would be deep enough, do you? I know it depends on the plants. Janis Petner, Houston
A: It can be difficult to garden in areas with lots of tree roots. I would not use a fabric bag or any type of planter or install a raised bed. As the tree ages, the roots thicken and may appear on the soil’s surface. Don’t add more than an inch or two of soil annually to hide roots, and don’t pile soil or mulch around the trunk base.
If you don’t care for the idea of a nice looking mulch or even a layer of attractive rocks beneath the canopy, I’d go with a ground cover. I’ve tried various ones beneath a maple with dense, fibrous roots. Consider these options: Australian violet — a lowgrowing, running plant with dime-size leaves and months of small white and violet flowers atop slender stems. You will occasionally need to snip it back into bounds.
Creeping jenny — a groundhugging spreader with chartreuse round foliage.
Knotweed — ‘Polygonum capitatum’ is a creeper with small, oval-pointed leaves that are a bronzy-green; in fall, it takes on shades of red, orange and yellow. Pink spherical blooms appear for months.
Vinca major — I’ve used variegated Vinca major. The loose, airy look of the green and white leaves is attractive in the shade, and in spring, this trailing periwinkle produces blue flowers.
Asian jasmine — The dark green foliage eventually makes a dense ground cover in the shade of a tree.
Ferns — Planted in pockets of soil between the roots, ferns are another option.
Keep in mind that tree roots are highly competitive for water and nutrients, so make sure added plants don’t dry out. Most of a tree’s feeder roots lie in the top 9-18 inches of soil, where they have greater moisture and oxygen exchange.
Q: We have had banana trees and squirrels co-existing until this spring. Now, the squirrels have eaten all the leaves. What can be done? Carol Castillo, Houston
A: Outsmarting squirrels is a never-ending struggle, and I’m not sure I can be of much help. There are numerous control or deterrent options, tried with varying or no luck, to prevent squirrels from munching on the leaves, especially the unfolding new foliage. These include trapping, a motion-activated sprinkler, scent-based repellents, wrapping a portion of the main stem about halfway up with a piece of sheet metal to prevent the squirrels from climbing up to the unfolding new leaves and netting the plant. Maybe one or more of these might help. Perhaps readers can share ideas that have worked.