October in the Low Desert
Did you plan your vegetable garden last month? Wildflower garden? Begin making a list for plant sale purchases? Plant sale is this month and it is a great opportunity to talk with the experts on desert plants and gardening, not to mention the fantastic array of desert-adapted trees, shrubs, cacti, succulents and perennials to choose from.
Monsoon moisture has left the state leaving in its wake drier air and cooler nights. The first half of the month might still be hot, but we should start seeing temperatures below 100º. You made it through another summer in Arizona; breathe a sigh of relief along with your garden!
Begin removing shade cloth that you might have placed to protect plants from damaging rays of the intense summer sun. Grasses will begin blooming this month. Watch for the beautiful, pinkish blooms on Muhlenbergia capillaris. Deer grass (Muhlenbergia rigens) will also be putting up cream-colored plumes now. Globe mallow (Sphaeralcea ambigua), Penstemon species, and brittlebush (Encelia farinosa) will resume growing.
Blooming now are Milkweeds (Asclepias species), Conoclinum greggii, Dicliptera resupinata, Tecoma hybrids, Cascalote (Caesalpinia cacalaco), Turpentine bush (Ericameria laricifolia), Rodney’s Aster (Symphyotrichum praealtum), and Superstition mallow (Abutilon palmeri). Leave any fruits of the season on the plants for wildlife to eat.
Once the temperatures begin dipping below 100º gradually start cutting back water to all plants to begin hardening them off for the winter. Remember, both frequency and duration need to be adjusted gradually. Do not stop cold turkey. Change your irrigation timer to reflect the changes in temperature.
What to Plant
Now is the time to sow seed for spring wildflowers, herbs and vegetables, along with most bulb seeds. Go crazy with planting, except for those plants that are very frost tender. This is an excellent time to plant in the low desert because the soil is still warm and temperatures are not excessive. This allows for roots to develop and plants to establish before the cold temperatures hit in December and January.
This is a particularly good planting time for those plants that are summer dormant, native to California chaparral or Mediterranean climes: Elephant tree (Pachycormus discolor), Boojum tree (Fouquieria columnaris), Baja senna (Senna purpusii), Joshua trees (Yucca brevifolia), Penstemon species, Lavenders (Lavandula spp.) and Salvia species such as Chaparral Sage (Salvia clevelandii), White Sage (Salvia apiana) and Golden Sage (Salvia officinalis).
Resume proper pruning at this time, pruning for general shape and balance and always for safety. Summer blooming shrubs can be pruned now, but hold off on those that are frost tender.
Stop fertilizing this month. Plants like to rest just as you do and most do this in the winter. Fertilizing will encourage new growth, which will be frost tender and more likely to be damaged should an early frost occur.
Insect activity should be tapering off this month. Mosquitoes are gone, a few whiteflies might be lingering, and some tomato hornworms might still be present (leave them alone if your plants can tolerate them).