Hot Gardens Newsletter: July 2005

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Water Here, Water There, But Not Everywhere.  There were days last winter when rain seemed to fall endlessly in some parts of the desert West.  In other areas the long-running drought continued.  But summer's return has brought us all back to the realities of living and gardening in a hot, dry climate.  Keeping plants alive and thriving through the summer months in the desert takes strategic watering and some careful work.  Here are some suggestions for preventing plant dehydration during scorching hot summer weather.

Polymers In.  Polymers Out.  Polymers, those water-retaining gel crystals, are usually used in flower pots to help cut down on watering and retain water in the soil for the plants' use.  Recently, however, we heard a gardener advocate using water-retaining polymers in flower beds and in the soil around trees.  It sounded like a good idea -- particularly in a climate where water evaporates out of the soil so rapidly that it leads to plant death by dehydration. 

But a little online research revealed a preliminary study which indicates that polymers may break down in our native soil into chemical components which may not be all that good for plants and people.  So while polymers may be a great solution for plants in pots, stick with adding organic amendments, such as crushed pecan hulls or finely ground wood chips, to your garden's natural soil to increase its water-retaining ability. Moreover, organic amendments add nutrients to the soil, which polymers don't.   If you would like to review the research yourself, to go Google and search for:  "Polymers Gardening."

Double Pot For Summer.  Another way to help your potted plants survive on the patio in summer is to set each pot in a second, larger container.  Then put an insulating layer of dried moss or coarse organic mulch between the two pots.  This will keep the inner pot cooler and protect plant roots from sizzling heat.  Consider using one of the newer plastic pots as your outer pot.  They are far more attractive than they used to be and conduct far less heat than terra cotta pots.  The insulation may also be helpful in winter, if you live in an area where it freezes in winter.

Lily of the Nile (Agapanthus africanus) and hybrid Canna lilies bloom in the South Coast Botanic Garden in Los Angeles.

 The Beauty of a Microclimate.  During a recent tour of Southern California gardens, we visited the South Coast Botanic Garden, about a mile from the ocean's edge on the Palos Verde Peninsula, and -- oh sigh -- it was gloriously abloom with Lily of the Nile (Agapanthus africanus) and Canna lilies in full sunlight. 

 In our Mojave garden we also have vigorous Agapanthus and Canna lilies -- but definitely not in full sunlight.  The harsh desert sun will burn them.  These mid-summer bloomers thrive in two sheltered, shaded corners of the garden with slightly cooler microclimates.  We have also planted an amaryllis bulb, left over from Christmas, and had it bloom in a deeply shaded and sheltered corner.  The lesson in all this is that microclimates can be home to non-traditional desert plants.

Reliable Summer Color.  If you want plants that you can count on for colorful blooms all summer long--even in scorching hot weather--go to our July 2004 newsletter.