Fall planting: It’s prime time for Southern California gardens
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The Dry Garden: Fall planting season
The question comes every spring as our state flower, Eschscholzia californica, blooms. “Is it too late to plant poppies?” The answer is no, it’s not too late. It’s perfectly late. Whether sowing wildflowers, or planting perennials and woody herbs and shrubs, or putting natives into the ground, the best time to plant here is in late fall or early winter. The idea is to do what the plants do naturally: Get seed in the ground in advance of the coming rainy season.
When the rain will start and how much will fall is anyone’s guess. For the second year running, meteorologists are reporting La Niña currents in the equatorial Pacific, which more often than not augur a drier-than-normal rainy season for Southern California. Although these La Niñas typically push wet weather north, they don’t always push it north of us. So while New Mexico and Texas suffered crackling drought last year, we received near-record rainfall followed by a remarkably mild summer.
In spite of that freakish fortune, the prudent thing to do in a La Niña year is to plan for unseasonably dry weather. In terms of fall planting, this means sowing wildflower seeds on the late side, from Halloween through Christmas. Planting of seedlings and bulbs can be done earlier, from early October onwards, keeping in mind that when Santa Anas blow in through December, you’ll need to irrigate to prevent the desert winds from wicking every last drop of water from newly installed plants and especially vulnerable stock still sitting in nursery pots.
If you’re an experienced gardener and working with nursery plants in one-gallon pots -- penstemon, monkey flower, sage, iris and ceanothus, right -- it’s worth trying an experiment. Treat them like roses or stone fruit, and plant them bare-root. I’m entering the second season of trying this experimental method recommended by Ventura horticulturist Jim Downer, and I am increasingly enthusiastic about the technique, which initially shocks a plant but also provides a more immediate bond with the plant’s new site.
Dig and then soak the planting hole. Moving fast, slip the plant out of the pot, tweak apart the roots and gently shake and poke off nursery soil and perlite. Then arrange the roots in the planting hole around a small central mound of earth. Making sure the roots are well distributed over the mound, backfill around them with fine (not rocky) earth. Tamp down the dirt to eliminate air pockets, and make sure you haven’t buried the crown, the point where stem and roots meet. Then water gently. Irrigate regularly as if the plant were still in a pot until the plant is established. After recovering from transplanting shock, the plant may require at least weekly watering during the cool season until rains come. Irrigation should be resumed as needed during the first dry season. After the first year or two, you should be able to wean the plant off supplemental water.
A wise horticulturist warned me against recommending bare-root planting of natives because it’s risky for inexperienced gardeners, especially so if you are prone to interruptions from small children or phone calls. Those exposed roots may dry out and die.
A prudent approach would be to try it with one nursery plant, and if it works, repeat it. If the sacrificial plant dies, install future plants the conventional way. Last year, working with starter stock from a number of native plant nurseries, the bare-root approach had a high success rate, partly because I had a good look at the roots of every plant that went in the garden. The Theodore Payne Foundation for Wildflowers and Native Plants was exemplary for rarely, if ever, selling root-bound seedlings.
Theodore Payne and Rancho Santa Ana Botanic Garden are among the native plant nurseries that will be hosting fall planting festivals and sales in October and November. Check their websites but also follow L.A. at Home’s Datebook listings for other regional events.
The benefit of buying wildflower seed from Theodore Payne is the romance of poking around the foundation’s seed drawer and the presence of a knowledgeable staff. The Los Angeles seed company Stover also deserves credit for consistently stocking fresh California native wildflower seeds in Home Depot and for offering a far more interesting collection from its online store at WildflowersOnline.com. If you’re a teacher buying wildflower seeds in quantity so child after child in class after class each gets a fistful of seeds to strew, Stover is a particularly affordable resource.
Wherever you get your seeds, Theodore Payne’s Lili Singer has a useful tip: Mix them with sand or dirt before tossing them, so slips of the hand don’t result in too much seed in one place. As obvious as this sounds, check the expected height of the flowers on the seed packets, planting taller flowers such as elegant clarkia behind shorter stock such as poppies and blue-eyed grass, right. Singer also recommends planting samples of each type of seeds in pots, so you have examples of young seedlings to help differentiate wildflowers from weeds.
Once wildflowers germinate, they will put out just enough foliage to begin slowly sending down roots. The real spurt won’t begin until after winter solstice. Steadily lengthening days of January and February spur the growth that results in a spring flush of flowers that always has people asking if April is the time to plant poppies.
-- Emily Green
Green’s column on sustainable gardening appears here every Friday. For an easy way to follow future installments, join our Facebook gardening page.
Photo credits, from top: Emily Green; Robert Lachman / Los Angeles Times; Francine Orr / Los Angeles Times