Most of us have heard variations of the line: "Americans will do the right thing once they've tried everything else." Welcome to gardening, which is precisely a process of screwing up until something works. Drought is teaching us that an addiction to lawn belongs firmly in the "everything else" category. This series has told readers how to get rid of their lawn, protect green infrastructure such as street trees, and build up soil to re-landscape with plants that are better adapted to our dry climate.
This penultimate installment is dedicated to the hands-and-knees gritty of actually planting trees and shrubs. It favors native plants because in nearly 20 years of growing cosmopolitan gardens on land where lawn used to be around homes and a large school, I've never seen an exotic come even close to matching a native for resilience, beauty, or sheer rightness in the landscape. The series does not address kitchen gardens or summer annuals -- that subject is capably covered elsewhere at KCET by Linda Ly. But, among the edible plants, this installment's planting suggestions do apply every bit as much to stone fruit trees, citrus, and woody kitchen garden shrubs such as lavender and sage as they do our native manzanitas or toyons. Above all, it stresses one of strongest recurring themes of this series, which has been asking gardeners to wait until fall to plant perennials. The reason? The full answer is below. The short one: We're doing the right thing this time.
1. Prepare the soil. Installing new plants immediately after removing grass is always a mistake. Remnant grass roots and seeds will respond to new irrigation, even drip, and colonize the root zones of the new plants. So, after sheet mulching, don't plant right away. Let the soil convert to an absorbent new medium while strategically weeding recurring grass for at least four months before succession planting. Start the sheet mulching described in Part Four any time from now through July and you should have soil ready for planting by late November.
2. Apart from food gardens, use native plants. When selecting natives, make sure they are not, say, redwoods. These are native, all right, native to northern rain forests. They fry in Southern California heat. So, when plant shopping, look for species from the Southland's greater floristic province. California sages are always my first choice for mixed borders because of their crazy beautiful scents and azure blue flowers. However, adding Salvia lemonii from New Mexico and Salvia greggii from Texas won't cost extra water and keeps hummingbirds going when many more locally discovered natives are dormant.
Once you've narrowed down what plants will thrive in your climate zone, winnow potential choices again to look for ones that enjoy similar conditions to those in your garden. A riparian western redbud won't be happy on a sun-blasted slope but is an ideal choice for a rain garden. Finally, know your soil type. Cleveland sage, for example, is ideal for the sandy loam of the foothills but tricky to grow in basin clay. The best way to see what might work in your garden type is to take a trip to Rancho Santa Ana Botanic Garden in Claremont, where the plants are grouped by adaptation. Never will studying feel more like a walk in the park. A good place to see a mix of natives and Mediterranean Climate zone plants artfully used together is Arlington Garden in Pasadena.
3. Buy small. Bringing home a plant that is root-bound is always a disappointment. However, if it comes from a small pot, not larger than one-gallon, it's usually an easy business to cut away a skein of surface roots, loosen the interior root system and get it into the ground fast enough that it will live and eventually thrive. But, with older plants in bigger cans, problems can run deep. Deformity after deformity can be disguised during up-potting from a nursery slip into a four-inch pot, then further transfers to a one-gallon, then 10-, 15-, and 25-gallon cans. I once bought a manzanita in a 15-gallon can that had three layers of matted roots growing over an original taproot that had hardened into a corkscrew shape. With slow-growing native shrubs such as manzanita, deformed roots can mean that the plant will not develop a healthy habit fast enough to beat the onset of heat and dryness. When shopping, always ask nursery staff for permission to look at the roots. Given the green light, tilt a pot downward enough to gently slip the plant from the pot.
Even if a large plant has been up-potted correctly, the larger it is, the harder it is to handle. Picking up a plant by the stem rather than the lip of the pot will tear at least some of the roots holding the soil. This damage will occur every time it is picked up and put down this way. The bigger the plant, the more the tearing. The more water weight in the pot, the more the serious the tearing.
Finally, size matters most on planting day. The bigger the plant, the bigger hole you have to dig and the greater the difficulty you face in seating the plant in the soil at the right depth. Seat it too high in a hole, and the plant becomes drought-stressed. Seat it too low, and soil build-up around the spot where the trunk meets the ground will lead to crown rot. Then there's cost. Buying large plants is expensive and all but guarantees problems, while buying small is cheaper and usually guarantees health. Buy small.
4. Planting season: You wouldn't plant just before winter back east. Planting just before summer in California is every bit as wrong. It asks a young plant to establish itself after transplant shock as the worst of summer heat is rising. Over-irrigating in summer is the most common solution, but it defeats the goal of saving water and risks deadly fungal and mold problems for our best-loved natives such as the ceanothuses known as "California lilacs." So don't do it. Rather, wait. Put plants in the ground as the days are getting shorter and air more damp. In cool coastal zones, that can be October. For most of Southern California, it's November. Thanksgiving is perfect. Planting while the days are short gives wildflower seeds and nursery saplings time to sink deep roots when light and heat stresses on the foliage are low. If it hasn't rained by the time you plant, irrigate according to nursery instructions and stop when rains come.
5. Site right: Before planting, place the cans with the plants in them where you've decided they should go. Stand back. Behold your estate. Rub your chin. Then check the grade for drainage. If it's a slope, get on your hands and knees and create a protected well large enough that irrigation won't run off the ground instead of soaking into it. Still don't plant. Rather, check what the plant tag and Doctor Internet say about the dimensions of the plant when it's mature. If the sage you've put two feet from a path says it will be six feet across in two years, move the plant. When massing plants such as lavender or sage leave an additional foot of clearance for weeding access.
6. Planting: Plant either early in the morning or late in the afternoon on a cool, preferably overcast day. Dig a hole only slightly larger than the can size. Keep the back-fill soil aside and dry while you fill the hole that you've dug with water. Allow the water to percolate into the ground. Fill it again. And again. When the soil in the planting well has been thrice saturated, take some of the dry fill and form a small mound at the bottom of the hole. Now, tilt the plant from the can, slip it out, and begin loosening the soil from its roots. You're going to throw the potting soil away -- it's best for the plant to establish itself in site soil -- so spill the nursery mix somewhere you can clean up, such as back in the can or onto a tarp. Working fast, get as much of the nursery soil off the roots as you can without tearing the roots or letting them dry out. Don't answer the phone if it rings. Hold the plant by the stem over the planting well. The point where the stem meets the root flare should be level with the soil line. If possible, splay the roots over the mound at the bottom of the planting well. If not, try to keep the roots reasonably spread out as you push in the dry fill soil. Using your fingers, push site soil under the trunk stem (air pockets kill). Once the plant and dirt are in, tamp the soil down with your hand. Water the plant. Let it the water percolate and water again. Check for air pockets, pushing dry site soil into any holes under the crown (wet soil is heavy and can tear roots). Water again. Let the soil settle overnight and check the next day to make sure there are no air pockets around the root zone. The National Arbor Day Foundation has good instructions about bare-root planting for trees.
In closing, a note about controversy over bare-rooting. Techniques are changing and the garden community is split on the topic. Five years ago, I converted to bare-root planting after hearing about it from Ventura County cooperative extension plant pathologist James Downer. In a fairly large planting experiment in a then-new third-of-an-acre garden, I found bare-rooting superior in every instance to the conventional method of simply loosening the very outer roots of nursery potted plants and installing them with the most of the nursery soil still on the roots. It worked for manzanita, mountain mahogany, toyon, ceanothus, coffeeberries, lemonadeberries, Oregon grapes, citrus, stone fruit, pomegranates, herbs, native sages, and even the supposedly finicky Matilija poppy.
However, Downer, it turned out, is something of an iconoclast. Outside of well-worn techniques for stone fruit trees and roses, bare-root planting is not a universally accepted technique, particularly for natives. Experienced horticulturists who I unreservedly respect such as Lili Singer at the Theodore Payne Foundation and Barbara Eisenstein from the wonderful gardening blog Weeding Wild Suburbia and Rancho Santa Ana Botanic Garden have argued that bare-rooting is too skilled a technique for beginners. They maintain that the risk of shocking and drying out roots of sensitive plants is too great. Readers should be aware of their concern, which may particularly come as a relief to those who simply don't care to get quite so surgical with the plants. It's always a good idea to discuss the best planting methods with nursery staff if you shop at places where workers are bound to be knowledgable such as the Theodore Payne Foundation in Sun Valley, Rancho Santa Ana Botanic Garden in Claremont, Matilija Nursery near Moopark, or Tree of Life Nursery in San Juan Capistrano.
*The next and final installment of After the Lawn will sum up options for how to save water through small changes straight through to wholesale relandscaping.
Follow the entire After the Lawn series:
After the Lawn: Part I
Designing Your New Garden
Caring For Your Turf
How to Remove Your Lawn
Planning Your New Garden
How to Design Your New Garden
Managing the Parkway
Transitioning to an Integrated Rain Garden
Assessing Your Garden's Water Needs