The Garden will be closed on Nov. 23 for Thanksgiving. On Nov. 24 and Nov. 25 the Garden closes at 4 p.m. due to Las Noches de las Luminarias.
Now is the time to begin planning for frost events. Historically, the first freeze can occur as early as the November 15. Purchase and/or stage your frost protection so that if and when an event occurs, you are prepared. Use a fabric such as N-Sulate, burlap or old sheets; never use plastic as it causes plants to burn where they come into contact with it. Frost cloth such as N-Sulate can be found at various garden centers.
Local garden centers will sell it by the yard, foot or in bulk rolls. N-Sulate is a medium-weight, permeable, UV-treated cloth that is reusable. If used correctly, it adds several degrees of warmth underneath. Drape material so it touches the ground around the edge of the plant in order to trap warm air and any heat radiating from the soil. N-Sulate frost cloth does have about a 30% shade factor, so although it can be left on for several days in a row, do not leave it on the plants the entire winter or for long periods of time.
Move your Karoo Rose (Adenium spp.) to a protected area such as a covered patio to protect from frost and winter rains. In case of a severe frost, bring the plant indoors for a short period of time. Check out our Desert Gardening Guide on Adenium for more information.
Winter growers should be leafing out by now: Boojum tree (Fouquieria columnaris) and Elephant Tree (Pachycormus discolor). Dudleyas, ice plants, succulent geraniums (Pelargonium spp.) and crassulaceous plants (Kalanchoe, Cotyledon, Echeveria) should be waking up, that is, if they made it through the summer! Other summer dormant plants waking from their summer slumber include Trixis (Trixis californica), Globe Mallow (Sphaeralcea ambigua), Brittlebush (Encelia farinosa), Senna purpusii, some Daleas (Dalea spp.) and Anderson’s Wolfberry (Lycium andersonii) and Penstemons (Penstemon spp.) will re-emerge if they died back to the roots during the summer months.
Flowering plants in November can include: Black Dalea (Dalea frutescens), Blackfoot-daisy (Melampodium leucanthum), Red Sage (Salvia coccinea), Mistflower (Conoclinium greggii), San Marcos Hibiscus (Gossypium harknessii), Damianita (Chrysactinia mexicana), Dyssodia/Dogweed (Thymophylla pentachaeta), and Desert Broom (Baccharis sarothroides). Many aloe species will also begin to bloom.
Look for winter bird residents such as the White-crowned sparrow, Orange-crowned and Yellow-rumped warblers, and Costa’s Hummingbird. Anna’s Hummingbird is still here as it is a resident year round.
Except on very warm days, reptiles, squirrels and ground squirrels will be inactive although cottontails will still be afoot. If the winter rains are slow to arrive, watch for damage on agaves, cacti and yuccas as the rabbits expand their dietary choices while they wait for the bounty of annuals that come with the rain.
Watch for fall color on Netleaf Hackberry (Celtis laevigata var. reticulata), Little Leaf Sumac (Rhus microphylla), Skunkbush Sumac (Rhus aromatica var. trilobata), Mexican-buckeye (Ungnadia speciosa), native Plumbago (Plumbago scandens), Arizona Rosemallow (Hibiscus biseptus) and Desert Rosemallow (Hibiscus coulteri). Some of your trees, shrubs, and herbaceous perennials will begin to lose their leaves for the season: Desert-willow (Chilopsis linearis), Elephant tree (Bursera spp.), Jatropha spp., Velvet-leaf Senna (Senna lindheimeriana) and Desert Senna (Senna covesii).
Summer tuberous plants will begin to disappear: Sacred Datura (Datura wrightii), Butterfly weed (Asclepias tuberosa), Globeberry (Ibervillea spp.) and Four-O’Clock (Mirabilis spp.). Summer growers such as Mexican Tarragon (Tagetes lucida) will also retreat to the ground. Do not water them as the plants may rot, and don’t dig them up as they are not dead.
Continue to cut back on watering. Water container plants twice per month or even less for cacti and succulents. Succulents generally do not enjoy being cold and wet. By the end of the month, your irrigation system should be shut down for the winter. The ground is cold, stays moist longer, and plants won’t be growing, so they need the rest. This will also harden off the plants for any frost that occurs. If the month produces no rain, consider an overall watering at the end of the month.
Finish planting those plants you bought at the fall plant sale and do water in. Did you miss the sale? Catch the next one the third weekend in March.
Continue planting annual and perennial wildflower seeds. Annual wildflowers such as Mexican Poppies (Eschscholzia californica ssp. mexicana), Desert Bluebells (Phacelia campanularia), and Owlclover (Castilleja exserta) can be planted now as well as perennial wildflowers such as Penstemons (Penstemon spp.), Native Verbena (Glandularia gooddingii), Blackfoot-daisy (Melampodium leucanthum), and native bulbs such as Bluedicks (Dichelostemma capitatum). Keep soil moist until seeds germinate then water once every two weeks if rainfall does not occur.
Cool season annual herbs such as cilantro, chervil, dill, caraway, borage, nasturtiums, biennial parsley and perennial fennel can also be planted now. Give them as much sun as possible. Sow seeds of cool season vegetables: beets, bok choy, carrots, collard greens, endive, kale, mustard greens, green onions, peas, head and leaf lettuce, radishes, rutabagas, spinach, and turnips. Plant transplants of cool season vegetables: cabbage, broccoli, Swiss chard, brussel sprouts, asparagus, head and leaf lettuce and cauliflower.
When planting trees or shrubs, they still need to be watered in and the root ball kept moist to become established, even though it’s not hot. Winter growers to plant in November include Lavenders (Lavandula spp.), Senna purpusii, and Cleveland Sage (Salvia clevelandii). Cold hardy agaves and yuccas can be planted at this time such as Havard’s Century Plant (Agave havardiana), Parry’s Agave (Agave parryi ssp. neomexicana), Toumey’s Century Plant (Agave toumeyana), Joshua tree (Yucca brevifolia), and Banana Yucca (Yucca baccata).
Avoid planting frost sensitive trees and shrubs such as the Coral trees (Erythrina spp.), Lantana (Lantana spp.) and Red Bird of Paradise (Caesalpinia pulcherrima).
Most trees are dormant by the end of this month. Deciduous trees, those that lose their leaves, can be pruned now as it is easy to see flaws that need correcting, such as crossed branches. Prune also for health and safety. Avoid lion-tailing, which is excessive interior thinning. This forces the growth of branches outward, straining and weakening them. Avoid pruning Palo Verde trees (Parkinsonia spp.) in the winter. More vigorous trees such as mesquites should receive a light pruning now. Shrubs and perennials that can be pruned now include Texas Ranger (Leucophyllum spp.), Globe mallow (Sphaeralcea ambigua) and Brittlebush (Encelia farinosa). Do not prune Yellow Bells (Tecoma spp.) or Lantana at this time. Encourage fresh new growth by pruning herbs such as thyme, marjoram, oregano, and rosemary.
Vines that go dormant can be pruned back to the ground for a fresh look in the spring. These include Coral Vine (Antigonon leptopus) and Yuca (Merremia aurea).
If there should be a frost event and your plants are damaged, do not prune them until spring when new growth indicates how far back to cut.
The winter growers mentioned above can be given occasional fertilizer. The rest of your plants should be allowed to rest, so no fertilization is needed. Add compost to your vegetable garden.
Problems with pests and diseases are not usually present at this time. If we receive rains in October or November, look for winter weeds to pull out.