This is the first month-by-month guide to gardening with native plants in a state that follows a unique, nontraditional seasonal rhythm. Beginning in October, when much of California leaves the dry season behind and prepares for its own green “spring,” Helen Popper provides detailed, calendar-based information for both beginning and experienced native gardeners. Each month’s chapter lists gardening tasks, including repeated tasks and those specific to each season. Popper offers planting and design ideas, and explains core gardening techniques such as pruning, mulching, and propagating. She tells how to use native plants in traditional garden styles, including Japanese, herb, and formal gardens, and recommends places for viewing natives. An essential year-round companion, this beautifully written and illustrated book nurtures the twin delights of seeing wild plants in the garden and garden plants in the wild.
California Native Gardening A Month-by-Month Guide
Change in the Air
The dog days of summer are only just behind us, and the soil remains parched until the first rains descend. Weeks of warm air and blue skies fill much of October. While Labor Day inaugurates fall elsewhere, Halloween is the eve of autumn here.
For many of us, planting is the month's biggest and most satisfying garden chore. Native gardeners in the mild-winter areas, where most Californians live, await the first soaking rains to signal the start of the planting season. Gardeners in areas overrun with deer prepare plant cages for anything they cannot resist planting now.
For gardeners who plant in spring or who have mature gardens, clearing away damaged wood and watering are the key tasks. Pruning dead limbs is a job to be done before winds knock them down for us. Watering brings forward the fall growing season, and deep watering ahead of a dry Santa Ana wind protects vulnerable plants from desiccation.
Whether we plant, prune, or water this month, we all can enjoy the local native plant sales, and we all can take in the month's montage of color. Asters, sunflowers, and California fuchsias (Aster spp., Helianthus annuus, and Epilobium spp.) still bloom brightly, while cool-season grasses begin to freshen, toyon berries color up (Heteromeles arbutifolia), and the leaves of maples (Acer spp.) are touched with gold. In October's garden, summer mingles with autumnal change.
October's Jobs-A Quick Look
Sow annual wildflowers
Rid the soil of weedy competition, water or wait for rain, then sow the seeds of California's colorful beauties.
Buy native plants
This is an ideal time to buy plants from native nurseries and plant sales for fall planting. If you have a place to shelter containers from weather and predation, you also can buy now for spring planting.
Begin to plant
For most of us, the planting season begins with the rains. Wait for soaking rains or prepare the site by watering deeply as soon as air temperatures cool.
Plant trees from seed
As soon as you begin to notice acorns on the ground, collect them from the trees themselves. Plant coast live oak (Quercus agrifolia) acorns soon after you collect them. Store other oak acorns in the refrigerator for a month before planting them. Start buckeyes (Aesculus californica), boxelders (Acer negundo), and California black walnuts (Juglans californica) from seed now.
Start cool-season grasses
Most of California's native grasses are cool-season ones. They are easy to establish in October.
Wind is on its way; remove any damaged limbs that are vulnerable to it. Rejuvenate perennials by cutting back the remaining ones. Add or remove mulch as needed.
Water new plantings and containers during dry spells, and water extra if those dry spells are windy. Once the cool days arrive, you also can water to nudge new fall growth along.
Native Gardening in October
Sow Annual Wildflowers
Sow California's spring-blooming annuals now, in fall. You can wait for the first soaking rains, or you can get a head start if you are willing to water. Some of the easiest and most arresting wildflowers are baby blue-eyes (Nemophila menziesii), bird's-eye gilias and globe gilias (Gilia tricolor and G. capitata), California poppies (Eschscholzia californica), and elegant clarkias and farewell to spring (Clarkia unguiculata and C. amoena). All are prized as much abroad as they are at home. Baby blue-eyes, clarkias, and poppies have been especially popular among the English, who have bred many clarkia and poppy selections. Globe gilias are popular with butterflies. Seeds of all of these annuals are widely available from specialty nurseries and sometimes even from big-box stores. In many locations, native specialists and local chapters of the native plant society are permitted to collect and sell the seeds of the locally native forms.
As easy as these native wildflowers are, they-like all wildflowers-have four key needs: the right location, relative freedom from weeds, protection from animals, and appropriate water. Many plants share these needs; but for annuals, the brevity of their lives, together with the fact that they typically are started in the garden from seed, makes them more exacting in their requirements. When their needs are met, annuals thrive and reseed themselves. If they are left to their own devices, the results will be as haphazard as the year's variation in the weather.
The right location provides adequate sun exposure, the preferred type of soil, and good drainage. Most of California's native wildflowers, including those above, need considerable sunlight. Notable exceptions include Chinese houses (Collinsia heterophylla) and red ribbons (Clarkia concinna), which grow in shade. While the easy germinators mentioned here are tolerant of most soil types, they do best in well-drained soils. (With good drainage, California poppies are perennials.) Some others, such as downingias (Downingia pulchella, D. concolor, and D. cuspidata) and meadowfoam (Limnanthes douglasii), are found in vernal pools and thrive in wet clay soils. For beautiful blooms, choose the right location.
Before wildflower seeds can be sown successfully in a new area of the garden, weeds should be allowed to germinate and then be removed. This requires some patience. The straightforward approach is to water the area as soon as the weather cools, and to continue to water until the weeds pop up. Then you can hoe them over and sow the wildflower seeds. Inevitably, some weeds will be missed, and you will want to follow up with more weeding later. If your sowing area is wide, you will have to decide whether the weeding is worth crushing a few seedlings along the way.
Consider sowing in drifts of a single species. While there are many wonderful native mixes available, single-species drifts make it easier to distinguish newly germinated wildflowers from weeds. They also help attract bees and butterflies, which often fly from flower to flower of the same species. Sow single species in drifts that are large enough-at least sixteen feet square-to be noticed by pollinators. That should bring in butterflies or native bees if they already visit your area. If such visitors are scarce, plant in still larger drifts so the pollinators will find your flowers.
To sow seeds evenly and help them come into contact with the soil, mix them into a handful or more of fine soil or sand before broadcasting them. If you have a few spare pots, sow some of the seeds in the pots and label them. The labeled pots will help you learn to recognize the seedlings, and they will provide something nice to give your friends in the spring. The pots do dry out more easily than the ground, so give them a little afternoon shade, and put them where they will be easy to water.
Once sown, the seeds need protection from birds, rodents, snails, and slugs. Some gardeners walk over the area to nudge their seeds into close contact with the soil. They then cover the soil with leaves or twigs and leave it at that. Others, relying on a technique popularized by the Theodore Payne Foundation, lay down pebbles before they sow. In the foundation's Fall 2008 newsletter, Dylan P. Hannon notes that "a light covering of gravel helps young plants flourish. A thin layer (one to two stones in thickness) of pebbles (about one centimeter in diameter) is sufficient." The seeds fall between the tiny rocks, which protect them from predation, weather, and movement. Still other gardeners use more substantial methods, such as covering the area with raised netting or row cover. When plundering is severe, or when the wildflower seeds are especially prized, ambitious gardeners sow in greenhouse flats and transplant the seedlings into the garden.
Appropriate water begins at sowing and continues throughout the life of annuals. Water gently at first, returning again and again with a fine mist so that you do not wash away the seeds or knock down the tiny seedlings. Ideally, you will have sown when rains are forecast, and you can leave it at that for a while; but rains are hit-and-miss everywhere in October and are absent altogether in some parts of the state. Water when it doesn't rain, and keep the soil moist when the air is dry and windy. As the winter rains fill in, so will the plants, and you will enjoy their fresh, glistening foliage as they make their way toward spring.
Buy Native Plants
In most of the state, natives are best planted in the fall, and native nurseries and botanic gardens anticipate gardeners' needs. So do the local chapters of the California Native Plant Society. From the North Coast to San Diego, local chapters hold their major plant sales in the fall, mostly in October. Experienced native gardeners and plant specialists preside, answering questions and guiding gardeners in their selections. They can help you choose the right plants for your garden conditions. While it is possible with great effort to modify your garden conditions, the easiest approach is to choose from among the plants that are native to your own area and that grow well in the conditions that already predominate in your garden. The Native Plant Society members at the plant sale can tell you which plants are native to the area and in what habitat they belong. The members propagate many of the plants they sell from local selections or from cuttings from their own gardens. This makes their plants good bets for your own garden.
Conventional nurseries now carry natives as well, sometimes in a special section, sometimes mingled with the nonnatives. Typically, you can find several garden-friendly species of ceanothus (Ceanothus spp., also called California lilac) and manzanita (Arctostaphylos spp.), as well as nonwoody perennials, such as seaside daisy (Erigeron glaucus) and yarrow (Achillea millefolium). Many natives are not showy in containers, particularly in the fall, so nurseries are sometimes reluctant to carry large inventories of them. However, most are happy to order native plants for individual customers. Several wholesalers who handle natives list their inventories online. By looking at wholesalers' inventories, you can get a good idea of what is easily available for your retailer to order.
Do not be discouraged if a nursery staffer earnestly tries to steer you away from natives, suggesting that they are "difficult" to grow. This increasingly rare view usually comes from inexperience, or from the unfortunate experience of planting a native that needs summer dryness alongside an exotic that needs-and gets-summer water. Politely explain what you would like ordered, or seek out a more knowledgeable horticulturalist (sometimes the nursery's buyer or manager) to assist you. You are now a native gardening ambassador.
Native botanic gardens and native retail nurseries-both online and on the ground-have much wider selections, along with dedicated, knowledgeable staff. Their inventories include many plants that have been selected for good garden features, such as a long blooming period, striking foliage, or adaptability to irrigation. The staff members are experienced with native plants that work well in home gardens.
Habitat restoration nurseries also sell native plants. Some are open to the public, though usually for limited hours. Restoration nurseries sell plants in large quantities, usually in pots that home gardeners are not used to, such as "rose pots" or "tree bands." The pots are sometimes just two or three inches wide but are quite deep. Compared with traditional one-gallon containers, these narrow pots require less digging, but they demand more experienced, or more delicate, handling. Expect the staff to be more focused on habitat restoration than on gardening. Like the wholesale nurseries, many restoration nurseries post their inventories on their websites, and it can be helpful to study the list before you arrive. If you have a large area to cover, you know what you want, and they carry it, then a restoration nursery is a good choice.
Choose the Right Size
Wherever you decide to shop, buy plants that are appropriately sized for your garden. In our desire for an instant filled-in look, we can be tempted to choose large, fast-growing plants and crowd them together. That approach is expensive, requires extra work both now and later, and ultimately results in unhealthy plants and a less attractive garden. Instead, space large plants appropriately and fill in with annuals or low, fast-growing native perennials that are either short lived or easy to pull out later. Or just mulch between the young plants to keep down weeds, then revel in the luxury of space and enjoy the wait.
You should also buy plants that are appropriately sized for their containers. Don't be put off by a small plant in what might at first glance seem to be an overly large container. The roots are often larger than the plant, and they need space. Worse yet, don't be seduced by a big plant in a small pot. While plants in small containers usually cost less than those in large ones, a plant that is too large for its container is no bargain. It may have been "pushed" with too much fertilizer or it may be rootbound, a defect that many plants (woody ones in particular) will never overcome. When cost is the overriding concern, buy small plants in small containers, and console yourself with their ease of planting and with the knowledge that plants from small containers catch up quickly.
When you get the plants home, keep them in a place that is sheltered from the sun and easy to water until you are ready to plant them. Nursery containers dry out quickly and heat up fast, so even plants that will require full sun once they are in the ground should be protected from it in the meantime. You may also want to group plants by their eventual location. If you are not quite sure where you will situate them, then group them by their origin (chaparral, redwood, etc.) or cultural requirements (sun with good drainage, shade and regular water, etc.). Grouping the plants will help you sort out their eventual locations, and it will help you keep them healthy until you are ready to plant them.
Begin to Plant
For most of us in California, fall is the ideal planting time. With shortening days, cool air, and still-warm soil, plants direct their growth to their roots. If put in the ground now, they will have ample time to establish themselves before the trials of summer drought. Whether we wait for the first soaking rains or nudge our gardens along with supplemental water as soon as the weather cools, fall brings us out into the garden with our trowels and spades.
For other gardeners, deer and winter freezes make fall planting less than ideal. The lush young plants from the nursery entice the deer, and juvenile "deer-resistant" plants often lack the defenses that confer resistance later. Planting now requires the installation of fences or substantial plant cages. The head start on the roots may not be worth the headache of protection. In areas with hard winter freezes, there is no head start at all; spring planting is preferable.
Whether one plants now or waits for rain or spring, planting entails preparation, the planting itself, and immediate follow-up. Begin the preparation by choosing the locations that match the plants' needs and your desires. With plants already grouped by habitat, put them in the parts of the garden that suit them best. Locate chaparral shrubs, such as island bush poppies and woolly blue curls (Dendromecon harfordii and Trichostema lanatum), on a slope or in coarse, fast-draining soil. Put redwood understory perennials, such as Pacific bleeding hearts and swordferns and (Dicentra formosa and Polystichum munitum), in shade and near a water source. Then, within these areas, give each individual plant enough space. If a shrub will grow to be six feet wide, center the planting hole at least a few feet from the mature plants around it, and even farther from other newly planted ones, which will grow larger. Finally, situate the plant to take advantage of the attributes you most admire. If the subtle, spicy scent of wax myrtle (Myrica californica) calls to you, plant it near a path, where you will release its fragrance as you brush against it from time to time. If you long for the old-fashioned delicacy of candied violets, plant mountain violets (Viola purpurea) where you can reach them easily, pick their flowers, and bring them into the kitchen.
Once you have decided where the plants will go, water both the plants and the sites well. Give them time to drain, then choose a cool day or time of day to begin digging the first planting hole. Push aside any mulch so it will not fall into the hole. Dig the holes substantially wider (as much as twice as wide) and a bit deeper than the plant's root ball or container. Scuff up the sides and bottom of the cavity, so the plant's roots eventually will be able to penetrate easily into the garden soil beyond. Scuffing is particularly important in clay soil, where a spade can leave behind a slick, impenetrable wall. Then build the bottom of the cavity back up again with the dug soil so that when the plant is placed in it, the base of the plant is raised slightly above the surrounding soil level.
Next, ease the plant out of the container. Loosen and unwind any coiled or turned-back roots. If untangling the roots leaves a hollow at the bottom of the root ball, then build up the center of the planting hole a bit more and spread the roots around it. Check to make sure the crown of the plant is high enough so that when you finish backfilling and tamping, it will be half an inch or so above the surrounding soil level. If the roots lie coiled at the bottom of the hole, then dig a little deeper so they have a chance to spread out. Backfill with the same soil you dug out, without fertilizers or other amendments. Be careful to keep mulch out of the hole, and try to fill it thoroughly so that there are no air pockets.
Next, using your feet, tamp down the soil around the plant to fill any leftover air pockets. Do this gently; overly vigorous tamping will crush the roots and compact the soil. Check the crown again to make sure that it is slightly above the surrounding soil. Most importantly, do not leave the crown in a depression, where water will stagnate, mulch will pile up, and fungal disease will thrive. Once the plant is well situated, finish by watering it thoroughly and mulching around it. Finally, remember that gardens change over time. As your native garden matures, you will move some plants, you will remove others, and you will plant again.
Plant Trees from Seed
Some gardeners start trees from seed and skip containers altogether. Mindful of the trees' ultimate dimensions and requirements, they sow seeds right where they want the trees to grow. Direct seeding entails losses, but it takes less work than planting from containers, and it costs much less. It also allows for excellent root development. Plant the big, ripe seeds of a buckeye (Aesculus californica) now. Or sow the seeds of a boxelder (Acer negundo) or a California black walnut (Juglans californica), or the acorns of a coast live oak (Quercus agrifolia). All are likely to catch up quickly with trees transplanted from containers.
Collect the acorns of blue oaks, black oaks, valley oaks, or Engelmann oaks (Quercus douglasii, Q. kelloggii, Q. lobata, or Q. engelmannii) when they just begin to drop from the trees. Collect the ones still in the trees; they are the healthy ones. Native Americans collect them by shaking the branches. You can do the same, letting them fall onto a tarp. Protect the acorns from drying out until you plant them. You can improve their germination by storing them in the refrigerator (that is, by using cold stratification). Remove their caps, soak the acorns, and toss away any that float. Some serious gardeners rinse the acorns in a dilute bleach solution-about half a cup of bleach in a gallon of water-to prevent mold. Finally, let them dry out briefly on towels or paper, and then store them in a freezer bag in the refrigerator. Remember that the acorns are alive; don't pack them in too tightly. If you notice a few germinating, plant those right away. Otherwise, keep them cool for a month before planting.
Once you have chosen the right locations for your trees, clear the planting areas of weeds, which can shade out young seedlings. To discourage early predation, some gardeners plant seeds in "collars." The collars can be made by removing the bottoms of cottage cheese containers and topping them with a cylinder of insect screen that is about eighteen inches tall. Or you can stake in a cylindrical cage of wire screen. If you do not use a collar or cage, you may want to put a stone or other marker nearby to help you to recall the seed's location and to remind you to weed around it and to water it.
For the lucky ones among us with mature trees, seeds give us an easy way to share our garden's bounty with a family member, a friend, or a neighbor. Watching a native tree grow from seed is a priceless pleasure.
Start Cool-Season Grasses
Grasses are versatile elements in garden design. Planted symmetrically or on a grid, they punctuate a garden with architectural drama. As lawns, they provide a place for play and social gatherings. In drifts and meadows, they evoke nature. They are equally versatile in their acceptance of propagation and tending. They can be planted from gallon containers or plugs. They can be sown from seed or laid as sod. They can be left to grow on their own, cut back periodically, or mowed regularly. Most of California's native grasses are cool-season grasses, and now is the best time to get them established in the garden.
October is a particularly good time to create a meadow or lawn from seed sown directly in the ground. The heat waves are behind us, yet most of the state still has enough warmth for the seeds to germinate easily, and the days are still long enough to support their growth afterward. For lawns, rhizomous grasses-that is, those that send out horizontal underground shoots-should be used. The rhizomes help fill out the lawn. One of these rhizomous grasses is Diego bentgrass (Agrostis pallens). With mowing, it forms a thick, drought-tolerant turf that stays green all summer if watered every three weeks or so. With somewhat more moisture and infrequent mowing, red fescue (Festuca rubra) forms a fine, hummocky lawn that is soft and inviting. Indeed, some of the prettiest native "lawns" are those that are mowed only a few times a year. In most of the state, a lawn or meadow seeded in early October should be green by Thanksgiving.
If a lawn is wanted right away, native sod-usually bentgrass or a blend of fescues-can be laid. While many gardeners reckon that seed-sown grasses-native or not-ultimately establish themselves better than sod, there is no denying that sod provides a speedy result. Whether one is hurrying to prepare the lawn for a social event or simply wants to privately enjoy the garden right away, a native sod provides a good alternative to a nonnative one. Some of the commercially available sods should be mowed regularly, while others use grasses that can be mowed occasionally or left long and undulating. To conserve on the expense of sod, one might lay just a small patch where immediacy is most desired and seed a larger area around it at the same time. The surrounding seed might be the same mix of species that is present in the sod, or it might be interplanted with bulbs, wildflowers, and other grasses to provide a meadow in the background.
Regardless of whether you lay sod, sow for turf, or sow for a meadow, you should rid the soil of weeds ahead of time. Just as with annual wildflowers, you can water ahead to induce weeds to germinate, then hoe them over once they have come up. A hula hoe (also called a stirrup, action, swivel, or scuffle hoe) works very well for this. To establish a satisfactory lawn or meadow, weed germination and hoeing should be repeated at least one more time before sowing. If there is heavy germination in the second round, then follow up with a third round. Preparatory weeding should not be skipped, even for sod. Sod will smother some weeds, but aggressive ones (sourgrass, oxalis pes-caprae, for example) will come up right through it. So while sod provides an instant effect, the effect will not last if the ground has not been properly prepared ahead of time. Weed hard ahead; hardly weed later.
Clean Up: Prune, Mulch, and Weed
Look around the garden for remaining deadwood, legginess, or spent flowers. Remove dead limbs from shrubs and trees now, before the Santa Anas or northern storm winds cause damage. Cut back mallow (Malacothamnus spp.) by a third or so; selectively thin redbud (Cercis occidentalis) and currant (Ribes spp.) to remove weak or crossing branches. If an old redbud is spent, you can coppice it (cut it to the ground) now, though it will take a long time to recover.
Rejuvenate perennials, such as asters, gumplants, monkeyflowers, and penstemons (Aster, Grindelia, Mimulus, and Penstemon spp.) by cutting them back now if you haven't yet, and if they are through blooming. You can also cut back buckwheats (Eriogonum spp.) if you like, but many gardeners prefer to leave their decorative seed heads on the plant for a while longer. Some perennials, such as sagebrush (Artemisia spp.) and island snapdragon (Galvezia speciosa), benefit from being cut back hard to prevent a woody buildup. For other perennials, use their new growth as a guide. If old woody stems have new growth, then you usually can cut back to that new growth. If they do not have new growth, then you can selectively remove a few branches, or you can try to promote side branching by pinching off just a bit at the very tips of the branches. If currants (Ribes spp.), some sages (such as creeping sage, Salvia sonomensis), and island snapdragons are producing new growth, then your pruning work will do double duty by providing cuttings as well as healthier parent plants.
Remove any mulch that may have built up around trunks or root crowns. Top off mulch where it is needed. When the rain arrives, it can bring a fresh crop of weeds, and mulch is helpful in keeping them at bay. However, you should not mulch where you plan to sow wildflowers or install native grasses from plugs, seed, or sod. Just as mulch keeps down young weeds, it also keeps down wildflowers and native grass seedlings. Hand-weed or hoe the areas you have newly cleared for wildflowers or grasses.
Fall growth begins with rain, which may come early, late, or not at all this month. If the weather is drier than you had hoped, you can nudge fall growth forward with supplemental water as soon as the days begin to cool. You can also keep many flowers, such as sunflowers (Helianthus annuus), blooming longer with a little supplemental water.
Once you have sown or planted, you must water during any dry spells. Containers that await planting also need regular water. Consider the wind as well in your watering regimen. Wind dries out new plants quickly, so when you hear a forecast of dry winds, give your plants a drink. In the areas hit by the hot, dry Santa Anas, even established plants benefit from deep soaking ahead of the winds.
What's in Bloom?
While school bells sound in the distance and pumpkins bedeck front porches, clever gardeners enjoy a concoction of color blended from three seasons. The bold flowers of late summer combine with an echo of spring and the heralds of fall.
A hot summer palette of red, yellow, and gold blazes through October. California fuchsias (Epilobium spp.) put out the hummingbird welcome sign of abundant orange-red, tubular flowers. The yellow members of the sunflower family, Asteraceae, parade on: annual sunflowers (Helianthus annuus) line the backs of borders; gumplants (Grindelia stricta var. platyphylla) spill sunny blooms over the edges of rock walls; and sweeps of California goldenrod (Solidago californica) support monarch butterflies in their fall migration.
A smattering of blue, lavender, lilac, and pink blooms also bridges summer and fall. With good drainage and just a bit of water, woolly blue curls (Trichostema lanatum) and lilac verbena (Verbena lilacina) continue to bloom. Pacific aster (Aster chilensis) and silver carpet California aster (Lessingia filaginifolia 'Silver Carpet') lend lavender and more lilac. Masses of ashy-leaf buckwheat (Eriogonum cinereum) add clouds of soft pink to the garden.
A subtle reprise of spring joins in. Renewed blooms open here and there on ceanothus, sage, wood mint, and monkeyflower (Ceanothus, Salvia, Monardella, and Mimulus spp.). Late-sown wildflowers, such as ruby-chalice and punch-bowl godetia (Clarkia rubicunda and C. bottae), flower along with the occasional California poppy (Eschscholzia californica).
The lingering summer pleasures and little spring surprises might distract us from the first indications of fall, but the signs soon overwhelm us. They begin with the bright golds and yellows of big-leaf maples (Acer macrophyllum) in the north, California black walnuts (southern California's variety, Juglans californica var. californica) in the south, and quaking aspens (Populus tremuloides) and black oaks (Quercus kelloggii) in mountain gardens. Vine maples (Acer circinatum) turn red in the sun, and western redbuds (Cercis occidentalis) and California wild grapes (Vitis californica) follow. When the berries of the toyons (Heteromeles arbutifolia) begin to turn color, the trick-or-treaters come knocking, and so does fall.