Fall is an especially good time to plant native and low-water plants.
Managing the watering is easier as the days get cooler. Root rot is less likely. The native plant club has its annual sale in late September. The Arboretum has a big sale in early October. Garden centers often have promotions or special sections just for native and “water-wise” plants.
There are lots to choose from, and more reasons than ever to consider some natives.
Wait, there’s more
* More information: The references in the past simply lumped all natives together as if they were interchangeable. We have dozens of different plant communities in the west, ranging in rainfall and summer and winter temperatures. Obviously, plants from regions similar to ours are going to do best here.
* More reasons: Loss of pollinators, enhancing beneficial insects in the garden to eliminate pesticide use, attracting butterflies and hummingbirds are all added reasons to consider native plants. Ironically, concern about the European honeybee (non-native!) has people wanting to plant native flowers to attract bees. Good news: our natives often do attract honeybees. Better news: they also attract native bee species, and other pollinators. And they attract birds and beneficial insects as well.
* More choices: Once just the province of specialty nurseries, now, good wholesalers grow native plants as part of their range of choices. Plant introduction programs such as the Arboretum All-Stars include natives. We can think of native plants from appropriate plant communities for landscape to mix with other plants from similar climates.
One of my pet peeves is the use of the term “California native.” California includes dozens of plant communities. Humboldt isn’t the same as Palm Springs! In Davis, we are in valley grassland; nearby are areas of oak woodland. We should focus on plants from those or similar plant communities. Plants from coastal dunes or redwood forests are less likely to succeed if you reduce your watering. Coast redwood (Sequoia sempervirens) is a California native, but it isn’t drought-tolerant.
When choosing natives here, we are broadly referring to dry-summer-adapted plants of western North America: plants from grasslands, oak woodlands, eastern Coast Range, Sierra foothills, chaparral and desert: areas with low summer rainfall, high temperatures, low humidity. That can include the Great Basin, grasses from the shortgrass Midwestern prairie, and even cactus and succulents from America’s deserts. We have relatively mild winters, so we can include plants from the southwestern United States and northern Mexico.
Reasons natives fail
* They aren’t from a similar plant community,
* They’re difficult to manage in your soil type.
* Key mistakes involving soil moisture management: You watered with drip irrigation; you watered too often; you amended the soil; and you piled mulch up against the stem.
All of those practices are very adverse for natives here. They encourage moisture retention around the stem, leading to rot.
* To give a shorter, somewhat more flip answer: Most native plantings fail because people choose the wrong types of ceanothus or manzanitas (the most popular natives), then plant them in heavy soil with lots of compost, and water them too often. With a drip system. Or they plant fremontias.
It is an excellent way to water your vegetable garden, or get a new orchard started. But not natives! Drip doesn’t distribute the water out to the whole root zone. It has to run for a long time, keeping moisture close to the stem for many hours, which encourages crown rot. Sprinklers are, surprisingly, an effective way to water natives to get them established. You just run them a lot less often than you used to, and a lot longer. Multiple cycles on the same day, at intervals of seven to 14 days, may be suitable through the first summer. By the second summer, many native plants can be unirrigated.
Natives to avoid
What’s wrong with ceanothus, manzanita and fremontia?
Bottom line: easy to kill. Very vulnerable to soil fungus.
* Ceanothus. The common name mountain lilac gives you a hint that they aren’t from around here. Showy, fragrant flowers in spring. Very attractive to beneficial insects, birds and pollinators. In general, look for Northern California species, selected cultivars and hybrids.
* Manzanita (Arctostaphylos). These come from many regions, though not here. Most need excellent drainage. Beautiful bark. Late winter flowers attract hummingbirds. A few garden cultivars are widely adapted. The successful manzanitas I’ve seen around town are usually completely unirrigated.
* Fremontia. You’re on your own. These just plain die. And they have really nasty hairs on the leaves that irritate your skin and are hazardous to your eyes. Big showy yellow flowers. If you’re going to try them, don’t water in summer (at all), and hope for the best.
How to succeed
Drainage around the plant is the key, along with careful watering in the first year.
The problem of moisture around the crown of the plant is easy to solve. Landscape areas and garden beds with natives should be higher than the surrounding soil. And the individual plants should be planted a little higher still.
This means that you add soil to the whole area where the plants are going to be installed. You can build a raised bed, or just create a gentle mound. It is best to use your native soil for this purpose.
Most topsoil you would bring in is sandy. That has two problems: It creates a saturated zone where the water rushes through the new soil and then slows down at the native soil interface. And the new soil dries out much faster, so establishing the plants in the first summer can be very challenging. In short: You end up having to water even more often, and then you have soggier soil down below.
Don’t add compost to the soil. Native plants should go in native soil. Compost retains moisture. And it breaks down over time, causing the area to get lower.
We want native plantings to be above grade so water percolates away from the crown of the plant during rainfall and irrigation. But you don’t have to go overboard: just a gentle mound of a few inches will suffice.
Note that this creates some low areas on the edge of the bed where water will tend to stand or drain slowly. Some plants, mostly sedges and grasses, will tolerate that. Or choose some attractive stones or cobble for those areas, or make them your paths.
When you plant, dig a wide hole, but not deep! The new shrub or tree should be about an inch above the surrounding soil. Break up the roots gently and spread them out. The backfill into the hole should just be native soil (no compost). Fertilizer, if any, should be a gentle organic source.
Make a basin around the plant so you can water it thoroughly, and fill the basin with water. If the plant settles, it’s very important to gently lift it a bit higher. Planting too low is a common cause of failure.
Water the new plant often enough to keep the nursery soil just moist. In the fall, that means every four to five days until rains begin. Additionally, water the entire bed very thoroughly every 10 days or so to get the roots growing outward. Once we’ve had an inch of rain, you can stop watering until next summer.
Mulch with care. A few inches of bark mulch retains moisture. Just keep it well clear of the stem of each plant. After you spread out the bark, take a rake and pull it away from each new shrub or tree so several inches are clear.
* Wrong plant, wrong place. Choose plants from the right plant communities.
* Incompatible with non-natives? This depends on how you’re watering your yard. You probably can reduce your frequency of irrigation considerably for many of your existing plants. Lawn watering will not work with natives, and affects the soil moisture a couple of feet out past your lawn. Natives shouldn’t be near the lawn.
* Often less tidy looking. Native shrubs have an informal growth habit that you may not be accustomed to, and most prefer light or no pruning. This is a different look, so plan accordingly.
* Less cooling, less comfortable summer environment. Watering less and using less lush plants can make the landscape feel hotter. Careful design and use of some non-native plants can help.
* Less summer color. Combining plants from similar dry-summer regions around the world gives you more choices and can make the garden more interesting and attractive. Lavender, rosemary and rockrose are examples of Mediterranean plants that can enhance a mostly native garden.
At the Ruth Storer garden at the west end of the Arboretum, note the mix of native and non-native species. The Arboretum nursery nearby has well-labeled displays. Nearby is the Carolee Shields White Flower Garden under the gazebo: mostly non-native plants, comfortably shaded and drought-tolerant.
The Sacramento Valley Chapter of the California Native Plant Society holds its fall native plant sale from 10 a.m. to 3 p.m. Sept. 28-29 at the Shepard Garden and Arts Center, 3330 McKinley Blvd. in Sacramento. Admission is free.
For UC Davis Arboretum events, check out arboretum.ucdavis.edu. Its next major sale open to the public is Saturday, Oct. 5.
Online resources can help you learn about natives. Very important: look for sources from the Western states! One of the best is Las Pilitas Nursery: www.laspilitas.com.
— Don Shor and his family have owned the Redwood Barn Nursery since 1981. He can be reached at [email protected]. Archived articles are available on The Enterprise website, and they are always available (all the way back to 1999) on his business website, www.redwoodbarn.com