Okay, you removed that thirsty grass in your front yard. You’ve also planted a tree or two or three around your home, shading at least part of your yard and the house, reducing the temperature. But off to the edge of your property–if your home is like most in the U.S. Southwest–is a dreaded gray concrete block wall.
That wall, if left bare, is a heat magnet. Nakedly exposed to direct sunlight the concrete absorbs heat during the day, even on cool days. Then after sundown, the wall releases the heat into the air creating a pool of warmth surrounding your home — just when you’re trying to cool things off at days end. And as the climate changes the wall-heater effect will only grow more intense. So what’s a smart gardener to do?
4 ways to help walls keep their cool
Plant shrubs in front of the wall. In one of my gardens I planted a row of the “Wonderful” variety of pomegranates (Punica granatum). These fast growers will reach a height of 6 to 10 feet. You may want to keep them trimmed to match the wall height because they can reach twice that height. Pomegranates need very little water. A special bonus with pomegranates is, of course, the fruit you can harvest in the late summer. In Fall the leaves turn a lovely shade of yellow before they drop. If you do not harvest the fruit you will have shrubs with bright red “ornaments” on them during the holidays. To see other shrubs for hot dry gardens, go here.
Plant tall grasses in front of the wall
On another wall in the same garden, a previous owner had planted Pampas grass (Cortaderia selloana). After a summer’s growth Pampas grass will be 8-10 feet high plus another 5-6 feet of seed plumes. And it does all this with little need for irrigation or fertilizer. By mid-winter, this perennial should be cut back to 18 inches tall. Be sure to wear gloves and a long sleeve shirt when you cut it back because the leaf edges are rough and serrated. It will re-grow to the same height in the following summer.
Avoid planting the variety of Pampas Grass called Cortaderia jubata which is a highly invasive weed. Given the right conditions — usually by a stream — it will self-seed and spread wildly forcing out native plants.
If you want to avoid Pampas grass — and many people do–another choice would be Deer grass (Muhlenbergia rigens) which grows to about 2 feet tall during the summer. It too grows seed plumes in Fall, but they are more modest in size than the ones of Pampas grass. While Deer grass will not cover up the entire height of your wall, it can be a base plant used with other shrubs. Unlike Pampas Grass it does not need to be trimmed back in winter. Needs very little water. To see other ornamental grasses for hot dry gardens, go here.
Install trellises along the wall
Plant climbers on the trellises–like a Trumpet Creeper (Campsis radicans) from the eastern U.S. It is a self-attaching vine with bright yellow and orange blossoms.
This vine can grow as much 40 feet in one year! Because it is such a vigorous grower and can become invasive, it is best planted in a large container beside the trellis or arbor. It is tolerant of a variety of soil conditions and of heat and cold. Needs moderate water in summer.
To see other fast-growing climbers and vines for hot dry gardens, go here.
For the unexpected — Kool Deck your wall
Paint your concrete block wall with “Kool Deck” or another heat-reducing finish normally used on pool decks. These finishes come in a variety of colors so you can give your garden walls a custom look.
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