Monsoon heat and humidity are upon us. The best strategy is to get garden work done early and head for cover!
Luckily, you have an excuse to curb some activities in your yard with this wicked weather. Pruning should be avoided unless absolutely necessary, such as to remove storm damage. If you do have to prune, remember to always use clean, sharp tools and make clean cuts to remedy broken branches.
Good rains will stimulate flushes of growth in our desert landscapes. This source of water benefits plants much better than our city water which is usually loaded with salts, so remember to set your irrigation timer system to the “rain” or “off” mode for a cycle after a considerable amount of rain. This will allow you to conserve water and you won’t be “diluting” the good effects of the rain.
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Chaparral Sage
(Salvia clevelandii)
summer foliage
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You need to be very cautious and avoid over-watering summer dormant plants. Too much water in the soil will cause rotting and/or fungal attacks of roots of these plants. Chaparral Sage (Salvia clevelandii) and White Sage (Salvia apiana) are good examples. They may look quite peaked at this time, but resist temptation to help them out with extra water. Baja Senna (Senna purpusii) will also look a little feeble now. These plants will resume activity by mid or late September. A succulent that can be easily killed with water-kindness is the summer dormant Aloe ramosissima. Again, allow it to look a bit shriveled or wilted for the time. Well-drained soil is critical for the root systems of any of these plants to prevent soggy situations when monsoon rains occur.
Nighttime temperatures are another challenge. When we don’t get sufficient cooling at night, many succulent plants cannot open their stomates, or pores, to take in carbon dioxide that would be reconfigured and stored for daytime photosynthesis to occur. The plant’s system will not be able to function, and appearance-wise the plant will seem to rot. The best we can do is anticipate the excessively hot nights that seem more frequent yearly, and try to locate these plants in cooler microclimates within our landscapes.
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(Acanthocereus tetragonus)
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With monsoon rains also come more blooms on a variety of Echinopsis. These cacti will bloom about eight days after a good soaking, displaying exquisite beauty for our enjoyment. Remember that most of the Echinopsis prefer a bit of shade relief midday and afternoon in the low desert. If you have any of the vining, arching cacti such as
Harrisia spp. or
Acanthocereus tetragonus, or the columnar Peruvian-apple Cactus (Cereus hildmannianus) expect spectacular night blooms. If you can’t stay up late enough to take in the beauty be sure to visit your garden early morning to catch the flowers before they wither with the days heat.
If you planted seed of some summer annuals in April or May, you should be enjoying the colorful blooms of Summer-poppy (Kallstroemia grandiflora) or Firewheels (Gaillardia pulchella) by now. Desert Senna (Senna covesii) is a dependable short-lived perennial that provides cheerful yellow flowers through the summer, no matter how high the temperature. Amoreuxia palmatifida is another native perennial that offers summer color. It is a great example of plants that are a little lesser known, but can sometimes be obtained at the plant sale of one of Arizona’s botanical institutions.
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Summer-poppy
(Kallstroemia grandiflora)
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Desert Senna
(Senna covesii)
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Summer is a time of both activity and inactivity in our desert gardens. Enjoy it!
June 2008
May 2008
February 2008
November 2007
October 2007
September 2007
Garden Meetings:
Central Arizona Cactus and Succulent Society Meeting
Sundays / 2 p.m. / September 28, Dorrance Hall / October 26, Wildflower Pavilion / November 16, Webster Auditorium / January 25 and February 22, Dorrance Hall. Everyone is welcome.
The Central Arizona Cactus and Succulent Society encourages the appreciation, study and growing of cacti and other succulents. Each meeting features a program about aspects of these fabulous plants. Call Judy Braun-Brody at 480-481-8129 for more information.
Arizona Native Plant Society Meeting
Tuesdays / 7-9 p.m. / October 14, November 11, December 9, January 13 and February 10 / Webster Auditorium. Everyone is welcome.
The Arizona Native Plant Society provides information about, fosters an appreciation of, and helps protect Arizona’s native plants. The Phoenix chapter emphasizes Sonoran Desert plants. Call Doug Green at 480-998-5638 for more information.
Maricopa Audubon Society Meeting
Tuesday / 7:30-9:30 p.m. / October 7 / Dorrance Hall. Everyone is welcome.
Call Laurie Nessel at 480-968-5614 for more information.
