Although we've just hit the fall season, it's time to begin winterizing our plants. Stop fertilizing and gradually cut back on watering frequency. This will encourage plants to slow down from the fall active growth phase, and toughen-up their foliage and stem tissues. Over-watering and fertilizing at this time will promote continued growth in plants, and this new tissue tends to be very susceptible to frost damage.
If you have chaparral sage, Salvia clevelandii, white sage, Salvia apiana, or Baja senna, Senna purpusii in your garden, you will notice that they are coming back to life after our wicked-hot summer. These plants are active from fall through spring, taking a break during the summer.
Brittlebush, Encelia farinosa and globemallow, Sphaeralcea ambigua will be leafing out with new foliage as temperatures moderate. Penstemons should begin regenerating from the roots if they have survived the ravages of summer. Allow them time to re-sprout rather than hastily pulling them out of the ground.
If you've planted strategically, your desert landscape can be full of color
this month. Turprntine bush, Ericameria laricifolia (above) is demure most
of the year, but the fragrant foliage of this small, drought tolerant shrub is
covered with bright golden yellow flowers through the fall. Butterflies are
drawn to this sun-lover for the nectar it offers.
Another butterfly attractor is Rodney's-aster, Symphyotrichum praealtum, syn. Aster praealtus (below). The erect stems of this beauty get so heavy with pinkish-lavender flowers that they tend to gracefully arch midway through the bloom season. If you allow this perennial to spread by its underground rhizome system, within a few years you will have a patch of irresistible nectar for a variety of native butterflies. The stems will die back to the ground at the onset of winter, at which time you can clip them back to ground level. Next spring new shoots will develop.
Birds will be indulging in the fruits of desert plants such as thornberry,
Lycium fremontii, L. exsertum. Be sure to try some yourself – you
might find their mild flavor enjoyable.
Any of the plants mentioned above are perfect for fall planting, as are most other desert landscape plants. Avoid planting frost sensitive plants, unless you are able to protect them from cold through the winter season. October is prime-time for casting wildflower seed in your garden as well. You can start seeding as soon as daytime temps dip down to 90° F. For more detailed information look for the Good Growing Guides Planting Trees and Shrubs, and Planting Desert Wildflowers, also on our website. Click here for Planting Guidelines: Container Trees & Shrubs another useful reference for recommended planting procedures, offered by the U of A Cooperative Extension Service.
If you have used shade cloth over any of your plants for summer sun protection, it is time to remove it.
Many feathered friends depend on the seed produced by our desert plants, so don’t be too diligent in raking up all of the seed pods and deadheading in your landscape. Avoid the use of pesticides. Many garden insects, such as succulent aphids and juicy gnats, provide necessary protein to get birds through the winter months. Round-tailed ground squirrels are getting ready to hibernate for the winter, and would appreciate all the mesquite pods that you leave for them. If they eat enough of seed now, they might not be as hungry for your tender annuals when they wake up in the spring (no guarantees, however!).
If your plants are plagued with whiteflies, spray the undersides of the leaves with a mild soapy-water solution, or a commercial insecticidal soap. Even better is to let beneficial insects such as ladybugs or green lacewings act as natural pest controls. The larval stages of these creatures devour the nymphs of the whiteflies from the foliage.
If grasshoppers are a nuisance, hope for cold weather to diminish the population.
Garden Meetings
Arizona Native Plant Society
Tuesday, October 9, November 13, 2007 January 8, February 12 and March 11, 2008, 7-9 p.m., Webster Auditorium
Central Arizona Cactus & Succulent Society
Sunday, October 28, 2 p.m., Wildflower Pavilion (silent auction), November 18, 2007, January 27 and February 24, 2008, Dorrance Hall
Central Arizona Butterfly Association
No meeting scheduled at the Garden in October
Maricopa Audubon Society
Tuesday, October 2, 7:30 p.m., Dorrance Hall
