By Scott Calhoun
When spring arrives, it is fun to sit back and watch your plants come alive again after winter with new growth and flowers. It’s fine to look over your garden and even feel a little pride, but a little time spent pruning will ensure that your garden will head into summer in top form.
Most popular ornamental grasses (e.g., deer grass, blue grama, and regal mist) for desert landscapes are warm-season growers -- that is, they grow spring through fall and go dormant in the winter. What this means to gardeners is that the plant will have lots of dried seed heads come spring, and grasses will look tidier if you give them a “big chop” early in the season to keep fresh green blades from mixing with old dried foliage on top.
You only need to do this once a year. Your plants will look like they got a bad haircut for a few weeks, but as new green blades grow, the grass will take on its old shape. The photo above shows blue grama before pruning, and the photo to the right shows it after. For this job, you can use bypass pruners or pruning shears.
Desert Trees: Light Pruning
Most of the desert trees in the Southwest can benefit, as least visually, from some spring shaping. A good number of the species used in desert gardens (e.g., mesquite, acacia, and palo verde) are naturally multi-trunked specimens. To make these into garden trees, it’s usually a good idea to select the two or three best low branches and make those into the trunks.
In spring, you’ll want to remove the small sucker branches -- usually smaller than your fingers -- that will grow into the interior of the tree (see photo). For these small finger-size branches, use a pair of bypass pruners.
Desert Trees: Major Pruning
After winter passes, you’ll sometimes encounter larger branches that have died back (see photo). It’s best to remove this dead wood early in the spring so that light can reach the living branches.
You’ll need a pruning saw for branches bigger than your thumb. It’s best to make three cuts to avoid stripping the bark off of the tree. Also, don’t leave stubs. Cut the branch almost flush with trunk, leaving a slight swelling (called the branch collar) of about ¼ inch. This photo illustrates proper pruning cuts on a mesquite tree. Remember: Don’t remove more than 25 percent of a tree’s canopy in any one pruning session.
A few other candidates for spring blooming include most tropical plants that may have been damaged from winter frost (e.g., bougainvillea, lantana, etc.). By taking care of dead plant stems and leaves now, you’ll enjoy several months of relatively carefree gardening.