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Using Native Grasses in Landscaping

Using Native Grasses in Landscaping

Compiled by Andrea Williams, Jim Hanson, and Laura Lovett of CNPS, with assistance from Reimagining the California Lawn by Bornstein, Fross and O’Brien.

There is a place for native grasses in the home landscape. Like other vegetation, they need to be planted away from the immediate 2–5′ perimeter of the house and maintained by mowing at an appropriate height. Both the height of mowing and the timing of it are key to encouraging the native perennial grasses and discouraging annual weedy grasses.

Perennial grasses have greater capacity to stabilize surface and sub-soils once established, they hold nutrients more tightly and recycle them more efficiently than annuals, they are less flammable than alien annuals, and they help to build soil organic matter, thereby increasing site fertility and sustained productivity. Perennial grasses are slower than many annuals in establishing themselves, growing soil-stabilizing root systems, and providing general soil protection. Therefore, regular weeding is necessary to keep competing annual grasses and weeds from shading out new seedlings until they get established.

Suggested Bunchgrasses to Use in Mixed Beds with Perennials

These perennial grasses stay green long into the summer on little or no water, where annuals will dry and cure usually by June. They are deep-rooted and adapted to local conditions, particularly purple needlegrass, and provide interest in the garden when mixed among flowering perennials. Deer do not eat grass, however, they may nibble on the perennials planted among them. Judicious siting of the grasses can help provide protection to plants favored by deer.

California fescue (Festuca californica) California fescue is a native, cool season perennial bunchgrass that is intermediate to long lived. A tall grass, 2–4 feet, with thick, chalky, blue-to-green foliage, it often persists with evergreen foliage throughout the year in milder environments. Tight clumps and a non-aggressive growth habit make it compatible with perennial forbs. California fescue plants become hardy at a young age and, once established, are tough survivors. Adapted to a variety of conditions, the species tolerates sun to intermediate shade and semi-drought, as well as moist soil along stream banks. However, it is most frequently found in the dappled shade, along the borders of woods, and on north facing slopes. Fall planting when soil temperatures are cooler is recommended.

Deer Grass (Muhlenbergia rigens) Deer grass is a 3 foot evergreen perennial with 2 foot plumes rising above the plant. It is fast growing, normally reaching mature size in a season or two. Excellent as a specimen plant or to add size and drama to a perennial bed. Plant in full sun to light shade. It will survive on no summer water but looks better if given a monthly deep soak. Performs well in clay soils. The extensive root system makes it excellent for soil stabilization. Remove the old leaves with a rake to keep it looking clean and to reduce fire hazard. It should only occasionally be cut back hard; usually a fall raking provides sufficient maintenance.

Idaho Fescue (Festuca idahoensis) Idaho Fescue or blue bunchgrass is native to western North America. It can be found in many ecosystems, from shady forests to open plains grasslands. This fescue is a densely clumping, long-lived perennial grass creating a distinctive rounded mound about 1.5–2 ft. in height. Idaho Fescue is good for a garden in cool summer areas, but also grows in hot summer areas with higher rainfall. Idaho Fescue likes full or part sun with fast-draining soil and low irrigation.

  • Festuca idahoensis ‘Siskiyou Blue’
    This hybrid of the native Idaho Fescue is notable for its enticing spruce-blue foliage. The thin leaves are much longer than the more familiar Festuca glauca, giving ‘Siskiyou Blue’ a softer, more graceful look. It doesn’t last long if you overwater.
  • Festuca idahoensis ‘Tomales Bay’
    This selection, discovered in Marin County, tolerates any sun exposure in coast sites, but requires part shade or shade inland. The foliage is bluer-green than the straight species and tolerates garden water better. Makes a compact dome about 18” high. Cut back in early spring.

Indian Ricegrass (Stipa hymenoides) Indian ricegrass is a perennial cereal grain native to the drier parts of Western North America. It typically grows up to 2 feet tall and a foot wide and spreads from seed, not vegetatively. It can live in sand to clay, but it does particularly well in sandy soils, and is an excellent choice for soil stabilization. Indian Ricegrass has strong ornamental qualities. The branching, wavy flower stalk and seed pods are so unique that it’s often used in flower arrangements. It’s a perfect plant for dryland gardens or drought-restricted areas and grows beautifully with other native grasses like wildrye and slender hairgrass, or alongside native wildflowers. The seeds are an important food for wildlife.

Leafy Reedgrass (Calamagrostis foliosa) This is a beautiful native grass of a very useful size and form for the landscape. It grows a foot tall by 18 inches wide in a beautiful arching mound that never needs cutting. The blue-grey blades and are topped in spring with impressive quantities of purplish feathery panicles that turn tawny with age. Quite low water in coastal habitats, it will require some shade and additional water in warmer interior sites. A very useful, undemanding and hearty accent plant that will be equally striking as a specimen or en masse.

Pacific Reedgrass (Calamagrostis nutkaensis ‘The King’) A large, handsome, evergreen, native bunchgrass that was sourced from the King Range on the North Coast, Pacific reedgrass is a unique component of coastal habitats. It has big, bold, strappy green foliage and a robust clumping form 3–4 ft. tall and equally wide. Purplish panicles (flower spikes) up to ten inches long rise a foot or two above the foliage. A good accent plant where you want some drama or need something larger. Best for woodland or partly shaded meadow, but will take full sun in somewhat cooler areas and needs to be irrigated as it looks poor without it. It is valuable for controlling soil erosion, and is capable of persisting even with the encroachment of eucalyptus and invasive grasses.

Purple needlegrass (Stipa pulchra) Purple needlegrass is a densely tufted, long-lived, upright perennial bunchgrass that is easy to grow and its deep roots help increase soil moisture and infiltration. Plants generally get 2–3 feet tall with airy purplish seed heads. They become dormant after seed production, but begin growth again with fall rain and will green up after summer dormancy even without the presence of precipitation. The species grows well in full sun as well as partial shade and is tolerant of extreme summer heat and drought. Young needlegrass seedlings grow at a much slower rate than most weeds. Without maintenance attention while seedlings are getting started, weeds can easily outcompete the new needlegrass seedlings for sunlight and dramatically impact establishment. However, once it’s happy it will seed around vigorously.

Nodding needlegrass (Stipa cernua) The panicles of thin, fine, nodding awns have a silky look and appear purplish, then dry to silver. They glimmer when backlit. The grass is fast growing and moderately long-lived. This plant works in small patches in gardens, with all soil types, and little or no water. Use it in rock gardens, rock walls, cactus gardens, or dryland perennial gardens. It prefers full sun and well-drained soils but will tolerate light shade, and has proven adaptable.

Tufted Hairgrass (Deschampsia cespitosa) Hairgrass has an attractive mounding habit and is famous for its airy plumes in shades of gold and silver, getting its name from the fine, hairlike flowers. They emerge green and then turn gold, forming glowing clouds about 3 feet above the base. A native to damp woods, bogs, and streamsides, tufted hairgrass prefers a cool spot in partial shade. Unlike most of our native grasses, tufted hairgrass requires summer water to thrive. If you have a moist spot, in sun or light shade, it will reward you with delicate tawny golden seed heads in late summer and graceful, bright green foliage the rest of the year.

Native Grasses Recommended for Use in Lawns

Cool season grasses are green in the spring and all through the fall when temperatures are around 65-75°F. Cool season grasses will require more water to stay green in a hot summer as it is their normal dormant period. However, they will thrive better if given a chance for some dormancy. Cool season grasses should be planted in the fall.

Warm season grasses will green up as summer temperatures go up, but go dormant and turn brown in areas with a cold winter. These grasses should be planted in the spring.

Warm season grasses flower and produce seed at the end of their summer growing season, while cool season species are productive in the spring and fall when temperatures are cooler and will flower late in each season.

The maintenance of California Native Sod varies depending on the variety you choose and your desired aesthetic. Each of the native sod offerings can be mowed or left nonmowed. Garden pathways and designated play meadows can be mowed into the grass area to allow foot traffic and greater accessibility throughout the landscape. It is best to determine the desired aesthetic and remain consistent with the maintenance program to maintain the look you prefer. Important features of these grasses are:

  • California Native Sod installed to provide a conventional lawn aesthetic will require weekly consistent mowing.
  • Non-mowed grass areas will produce a seed head in the spring. This is often mistaken as a weed invasion. If desired, the seed heads can be cut off with a string trimmer. Left alone, these beautiful flowers of the grass blow in the wind providing a seasonal splendor for which California is famous. Summer heat will turn the seed heads golden brown, causing them eventually to cascade over and mulch into the green grass below.
  • Should you which to convert a non-mowed area to mowed, it is important that the area be cut back gradually. You should never remove more than 1/3 of the leaf blade during cutting. When these grasses reach full maturity, they fall over on themselves and shade out areas below. Cutting the grass will reveal these areas and may be unsightly. Well timed mowing in the early spring will ensure that these grasses recover and fill in the open spaces.

Native or California bentgrass (Agrostis pallens) Agrostis pallens is the best choice as a local, irrigated, true lawn substitute. If people really want a spot they can walk or picnic on that looks and acts and needs maintenance like a real lawn, bentgrass is the ticket. It is one of the leading cool season native lawn species throughout California, being incredibly durable and able to withstand heavy traffic and low mowing heights. Native bentgrass thrives in both full sun and partial shade and is extremely drought tolerant. Left unmowed to flop, it creates the look of a natural, informal meadow.

Red fescue (Festuca rubra) Red fescue is a popular native lawn species with several regional varieties that can range from turf to ornamental use. A cool season native that thrives in partial shade, it’s also wear-resistant enough to withstand heavy foot traffic and recreational play. You can leave it unmown in cool months and mow to 4” during summer fire season. Height to 2.5 ft., blooms May-June and then is summer dormant. Expect it to spread quickly if it has water.

  • Festuca rubra, Molate strain Found on Point Molate near Richmond, this selection spreads to form soft, flowing drifts of gray-green foliage 12–18 inches tall. Plant in full sun to light shade. Very choice for a meadow or parking strip. Prefers some afternoon shade in the hotter climates and occasional water away from the coast. More drought tolerant than many other red fescues, but will need summer water to stay green.
  • Festuca rubra ‘Patrick’s Point’ Discovered on a rock at Patrick’s Point on our north coast, this 1 ft. clumping perennial grass slowly spreads by creeping rhizomes to form tufted drifts of silvery blue. Effective as a smallscale groundcover. Typically at its best in situations where it is either unmown or infrequently mown. Plant in full sun to light shade. Protect from the hot afternoon sun in inland areas. Will need irrigation to stay green through the summer.

Clustered field sedge (Carex praegracilis)
Dune sedge (Carex pansa) Sedges require more water than grasses, but they are evergreen and generally more shade tolerant. Both of these are short, green sedges growing to 6-8 inches tall and spreading by rhizomes to form a carpet that tolerates moderate foot traffic. Both can be used as a solid ground cover, between and around steppingstones, or with perennials and grasses to create a natural meadow look. If left to grow they have a lush, tousled appearance or they can be trimmed into a flat green lawn. Takes full sun to partial shade but without summer water it will turn varying shades of tan and brown.

Lippia (Phyla nodiflora) Lippia is a low perennial that can work as a lawn substitute. It’s nice but less springy underfoot and it doesn’t tolerate regular foot traffic—it’s more of a visual substitute for a lawn rather than a surface to use actively. It becomes semi-deciduous and dormant under winter conditions. Lippia grows rapidly during the spring and is covered with numerous small purple and white flowers, which are highly attractive to bees. It needs supplemental water to stay green and can be mowed as low as 1 inch.

Seed Mixtures Many lawns are often a mix of several species to provide the color and growth habits that are desirable as well as the seasonal stability that polycultures can offer. Many companies make mixes of native grasses that combine the qualities of different plants for use as lawns, or in meadows or swales. Delta Bluegrass Co. in Stockton has numerous options including the Native Mow Free blend that uses a trio of grasses: Festuca idahoensis (Idaho fescue), Festuca rubra (Molate fescue) and Festuca occidentalis. It is very shade and cold tolerant, and requires little mowing. The Huntington Library has Mow Free now installed in all new construction. www.deltabluegrass.com

Maintenance
All grasses need some maintenance and for those that get cut back, the timing and height of shearing is important. When planting a mixed bed from scratch, for the first summer mow the vegetation back to 6” high each time it gets to 12”. A string trimmer will cause the least damage. This will push the perennials to create a strong root system while preventing the annual grasses that move in from setting seed. Weed diligently.

Spring Shearing to reduce annuals and weeds. If you have an excess of unwanted annuals, esp. annual grasses, showing up in your garden bed, mow everything to about 4–6” in height after food reserves have moved into the seedheads of the annuals but before the large seeds are viable, usually about April. Avoid the green forbs (perennials) and the base of perennial grasses that are sprouting. The idea is to remove only the seed heads of the annuals so they don’t reseed. A string trimmer or a pair of hedge clippers works well, or use an electric hedge trimmer if you really have a lot to do.

Many gardeners plant native grasses in drifts interspersed with common grassland flowering forbs and annuals, such as gum plant (Grindelia sp.), California aster cultivars (Symphyotrichum chilense), pearly everlasting (Anaphalis margaritacea), buckwheats (Eriogonum), and Clarkias.  Complete a second trimming after these types of perennials have bloomed but before new growth starts with winter rains.

Fall Shearing to provide space and light for new seedlings. Many perennial grasses tend to seed and turn straw-colored by June, but the remaining seed stalks (or inflorescences) continue to sway in the summer breeze. The second trimming—this time of perennials and bunchgrasses—can be done in July if you are concerned about fire, or in the fall to clean up everything for winter. If you want to leave the seed heads over the winter, you can do cleanup in mid to late winter. Trim back perennials that need reshaping, and cut warm season bunchgrasses to 4-6” high, being careful to avoid damaging the crowns. This readies the garden for regrowth in the spring.

Native grasses mingle with checkerbloom and Douglas iris at the San Francisco Botanical Garden. Photo © Saxon Holt, Photobotanic

Purple needlegrass on retaining wall Photo by Nita Winter / Rob Badger

Seedlings

Swath of California fescue plants with edible planters in background. Photo by Stacey Pogorzelski

Seedlings

Muhlenbergia rigens - deer grass Photo by Ann Elliott

Festuca idahoensis 'Siskiyou Blue'

Stipa hymenoides - Indian ricegrass

Stipa pulchra - purple needle-grass Photo by Vernon Smith

Calamagrostis foliosa - leafy reedgrass Photo by Laura Lovett

Deschampsia cespitosa - tufted hairgrass Photo by Vernon Smith

Festuca rubra - red fescue Photo by Vernon Smith

Carex praegracilis - field sedge Photo by Vernon Smith

Anthoxanthum occidentale - vanilla grass, CA sweet grass

Rewilding: A Native Habitat Garden in the Making

Rewilding: A Native Habitat Garden in the Making

Caroline Christman

All photos by Nita Winter and Rob Badger

Starting a garden renovation can be overwhelming; it is hard to look past what exists now towards the native habitat garden that could be.  Whether starting with a blank canvas or transforming an existing garden, it is a challenge to the imagination. In some situations, it makes sense to develop a garden design and implement all the changes at once. For others, working gradually to transform a garden may be the best path: adding native species each winter, removing invasive species, and seeing how the garden adapts over time. This is a story about a gradual process of transformation and the delight in watching a habitat garden emerge.

Nita Winter and Rob Badger live in Marin City and have a 0.25-acre lot dominated by a sunny, southwest facing slope. As conservation photographers focused on California wildflowers, they have considerable experience with observing and appreciating native California plants and their habitats. Over time, this led to an interest in bringing native plants back into their garden. The change began slowly but has picked up momentum as Nita and Rob’s interest in creating a native habitat at home has grown. They think of the process as rewilding.

When Nita and Rob first moved in, the back garden was dominated by Monterey pines and Monterey cypress interspersed with plum trees. Ice plant, aloe, and other succulents covered the sunny hillside. The garden was drought-tolerant, but there was lots of room for improvement to provide habitat for native birds and insects. A California buckeye (Aesculus californica), a few small coast live oaks (Quercus agrifolia), and a scattering of blue-eyed grass (Sisyrinchium bellum ) showed the potential for native habitat to return.

The rewilding process began when the front steps needed to be replaced in 2002. The small construction project cleared space for the first native planting, a few California blueblossom (Ceanothus thyrsiflorus), purchased at a CNPS native plant sale. Over time the first ceanothus bushes have grown to form an evergreen hedge alongside the new stairs, with blue flower clusters that attract many native pollinators, including a variety of bees.

The next big step in the rewilding process occurred in 2015, when the retaining walls in the front yard needed work. Installing the new retaining walls created two long, flat, blank canvases. The first winter, Nita and Rob selected one of the planting areas to focus on and filled it with native bunch grasses and wildflowers, including deergrass (Muhlenbergia rigens), narrow-leaf milkweed (Asclepias fascicularis) to support Monarch butterflies, and California fuchsia (Epilobium canum). The second retaining wall was planted a few years later, after the couple received free plants from nearby native gardens. During this time, purple needlegrass (Stipa pulchra) volunteered in the new planting areas, probably drifting in from nearby natural areas. The purple needlegrass helped to fill in the gaps, showed what native species could be successful in the garden, and perhaps gave a glimpse of what habitat was here before the area was developed. Nita and Rob were glad to have the purple needlegrass and helped it spread by transplanting a few plants in the front yard, and then watched happily as it made its own way into the back garden.

For a small garden, one of the challenges is carefully selecting which plants to include in your limited space and thinning or removing plants if they begin to crowd out other species. For a large garden, finding enough plants to fill the space can be a challenge; this is where Nita and Rob found themselves.  Nita and Rob reached out to their fellow native plant gardeners and in 2019 were gifted plants that were overcrowding the small Bay Model Pollinator Garden, a CNPS demonstration garden in nearby Sausalito. One useful species they received was Pacific asters (Symphyotrichum chilense). Asters produce a multitude of lavender blooms in the summer, which are favorites of bees and butterflies, followed by seeds favored by birds. Asters spread quickly via rhizomes and can overtake other plants, a challenge for a small garden, or an asset when there is a lot of ground to cover. Nita planted the asters in the new retaining wall planters in the front garden and on a steep, hard-to-access slope in the back garden that is subject to erosion. Over 3 years, the patch of asters in the back garden has grown to cover a 15-foot by 20-foot area, spreading over the slope and keeping the soil intact. For Nita, planting native species that spread easily via rhizomes (such as Pacific asters and milkweed) or seed (purple needlegrass) helps fill in large open areas more quickly. An enthusiastic gardener can help plants spread by transplanting rhizomes to new areas in need of cover. For prolific seeders, seeds can be collected and spread into new areas or sown in containers and nurtured into young plants for planting.

A third big step in the rewilding process was initially undertaken with safety and fire concerns top of mind. The couple noticed the Monterey pines (Pinus radiata) and Monterey cypress (Hesperocyparis macrocarpa) which shaded the back garden were dead or dying. They removed these trees, along with fire prone junipers clearing the way for coast live oak to return. On the California coast, coast live oak (Quercus agrifolia) are integral to oak woodland communities, an ecosystem that provides habitat for numerous species such as the beautiful California sister butterfly and charismatic Steller’s Jays (California Oaks). Now, on the ridge overlooking the house, a row of young coast live oak trees reaches towards the sky.

After Nita and Rob began to clear the way, wildlife began to play a large part in remaking this garden. The oaks on the hillside were planted by scrub jays, not by Nita and Rob. Over the years one toyon (Heteromeles arbutifolia) has turned into many as cedar waxwings, Western bluebirds, and thrushes have eaten the berries and spread the seed.  Purple needlegrass has moved, with the help of awns twining into fur and clothing, from the front yard to the back to create a small native grassland on the sunny slope. Human hands support the transition by removing invasive plants and bringing in appropriate new species to increase diversity. In the purple needle grass prairie, Nita removes bur clover (Medicago polymorpha) and vetch (Vicia sativa) in the spring to allow young needle grass seedlings to thrive. A scattering of soap root (Chlorogalum pomeridianum), California poppy (Eschscholzia californica), and coast buckwheat (Eriogonum latifolium) have been added to compliment the grassland. Many species are now multiplying and spreading on their own, with many soaproot and ceanothus seedlings being found like tiny treasures during spring weeding sessions. In this garden, humans and nature are working together to restore the hillside habitat.

Nita and Rob have long been interested in including plants to support pollinators such as native birds, bees, and butterflies.  They planted narrow-leaf milkweed, host to monarch butterfly caterpillars, in conjunction with nectar-rich plants such as ceanothus, California fuchsia, and coyote mint (Monardella villosa) to attract adult butterflies to the area. The planting palette has generally been a success, with 37 monarch caterpillars seen in April 2024. They are also enthusiastic about the bird life they can see from their back windows, which they have encouraged with shallow bird baths and a bird house, as well as with native plants. The bird house attracted a pair of Western bluebirds as soon as it was installed, and Nita and Rob watched them raise two broods that year. Nita says, “We have seen more birds as the oaks get bigger and there are more flowering plants. We have documented 50 different species of birds appearing on or above our property over the past few years, with short visits by very special migratory birds such as the extremely colorful Western tanager and lazuli bunting. These birds have brought us so much joy every day.”

Another key factor to consider in choosing plants and planting locations is how much deer will enjoy eating them. At Nita and Rob’s house the back garden is fenced, but the front garden is not, and deer browsing is a concern. Nita says, “We’ve had to learn, sometimes the hard way, what the deer will eat and what they will leave alone. We caged some plants to let them get established so the deer browsing will only trim the plants and not destroy them.”  For example, when they transplanted small toyons that were volunteering in potted plants they had to cage them at their new locations to keep the deer from eating all their new shoots and leaves.

All of this gardening is a lot of work, but it can also be a lot of fun and a good way to build community. Attending garden tours and participating in plant and seed swaps is a great way to meet other native habitat gardeners, to share plant materials, and exchange information. Many of the plants going into Nita and Rob’s garden come from friends they’ve met through native gardening events who have their own native gardens nearby. Recent additions from plant sharing include hedgenettle (Stachys ajugoides) planted under the oaks, California phacelia (Phacelia californica), and California goldenrod (Solidago velutina ssp. Californica). A lovely red-flowering currant (Ribes sanguineum), now thriving in the shade of a plum tree, was originally a cutting from a plant exchange.

This gardening odyssey started with photographing California wildflowers. Now, after years of rewilding the garden, Nita and Rob are thrilled that they don’t have to leave home to find beautiful plants and wildlife to photograph. They can step outside into their very own yard and discover exciting creatures to photograph any time of the year. With about 45 native plant species and a medley of wildlife to view, they can photograph in the yard when they aren’t able to travel.

For Nita and Rob, rewilding is an ongoing process that involves observing the garden and making changes based on what happens each year.  As keen observers, they note which native plants are doing well and being utilized by wildlife; are they spreading or self-sowing, are they blooming and thriving? At the same time, they consider which invasive species are spreading and how quickly they are moving into new spots to focus their weeding work each season. When asked how garden goals have changed over time and what lessons have been learned, Nita says, “We’ve learned to be flexible and not feel like we have to control a native garden. The garden will never be fully completed. It will always be changing.”

To learn more about Nita and Rob’s photography please visit their website: WildflowerBooks.com

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Interested in creating or updating your native garden? CNPS has many great tools available online, here are just a few:

Other Resources for creating a pollinator garden:

 

Ceanothus along front steps

Purple needlegrass on retaining wall Photo by Nita Winter / Rob Badger

Anna's hummingbird feeding at California fuchsia

Pacific asters

Coast live oak acorns

Monarch butterfly caterpillar on narrow-leaf milkweed

Monarch butterfly emerging from chrysalis

American painted lady caterpillar in oak leaf litter

Buttercup, California poppies, aster, and ceanothus spreading on the hillside

Western bluebird on Toyon

Flower fly on ceanothus blossoms

Springtime Weeding

Springtime Weeding

Nita removes bur clover from around purple needle grass.
Photo by Caroline Christman

Choosing which non-native plants to remove

Caroline Christman

As the wet weather fades away and days get longer, our gardening efforts shift from planting to weeding. While the soil is moist, we pluck out small, young weedy plants before they establish and set seed. Well, at least that’s the goal, but it’s not possible to get everything. And it’s not really necessary to remove every non-native plant from the garden. Which brings us to the all-important question – how do we decide where, when, and what non-native plants to control

This spring I’ve worked with gardeners on weeding projects in several native habitat gardens in Marin. On one sunny hillside in Marin City we focused on bur clover (Medicago polymorpha) and vetch (Vicia sp.) competing with purple-needle grass (Stipa pulchra) and soaproot (Chlorogalum pomeridianum). On the north shore of Tiburon we scoured the small coastal prairie for bristly ox-tongue (Helminthotheca echioides) and Italian thistle (Carduus pycnocephalus) and dug-out the taproot of small fennel plants (Foeniculum vulgare) whenever we saw them. At the Marin CNPS Bay Model Pollinator Garden we focused on panic veldtgrass (Ehrharta erecta) hiding in the shelter of native shrubs and making its way out to fill in all the open soil.

In each garden mentioned the weeding focus was different. We made choices of where and how to work based on multiple factors including: native species or plant community to protect; abundance of particular non-native species; likelihood for a non-native species to crowd out natives and alter the ecosystem; manner and speed at which the species spreads (seeds, rhizomes); most effective methods for control and removal; and difficulty of removing a mature plant.  

Laura Weeding in the Bay Model Pollinator Garden
Photo by Caroline Christman

Protecting Native Plants:
In the spring, new plantings will benefit greatly from controlling weeds near their base.  If irrigation is directed to new plants, weeding is especially important to ensure the weeds are not gaining all the benefits of late-season water.  Some plant communities and locations are vulnerable to invasion even after plants are established. Grasslands, for example, contain many low-growing forbs and have spaces between native bunch grasses that fill with annual wildflowers in the spring. Maintaining a native grassland requires on-going invasive species control to keep weeds from filling in the spaces and towering over the smaller plants. Areas adjacent to roadways, paths, or other sources of weed seeds, are also likely to need continuous attention.

Assessing Potential Weedy Species:
Some non-native species are higher priority for control than others, and this varies from place to place. In wildland settings, some species are well-known for spreading quickly and creating dense monocultures (a large area of a single plant species). For example, French broom (Genista monspessulana) and jubata grass (Cortaderia jubata) are highly invasive non-native species which drastically alter ecosystems. In a garden setting, however, highest priority weeds may not be the same as in natural areas. 

Getting to know the garden and watching it change over time is helpful to understand potential invasive issues. In the Tiburon garden, for example, several years of intensive French broom removal had allowed the remnant grassland to regenerate. We chose to focus on Italian thistle and bristly ox-tongue because we had seen these species spreading into the grassland from a nearby construction site. Both of these species are in the aster family and produce thousands of wind-blown seeds; a few Italian thistles left to go to seed one year may result in hundreds of thistles the following year. We also made sure to remove any small fennel or broom plants we came across because these are much easier to remove when small, and we didn’t want to let even one plant flower and seed. In the Marin City garden, Nita (the owner) had seen the bur clover and vetch populations expanding, also in a grassland. Both are in the pea family (Fabaceae) and are nitrogen-fixers like many legumes. In fact, bur clover is planted for forage and to increase nitrogen in the soil in agricultural settings.  In a native grassland, however, both species can alter the soil and make it more hospitable to invasives. 

Walking the garden regularly, observing new invasive species making an appearance and those trying to take center stage, will help us in recognizing new threats. Learning about the way invasive species alter the habitat, how they spread (seeds, berries, rhizomes) and how quickly they multiply, and how difficult they are to remove is the next step.

Tools for Weed Assessment:
Links for invasive species above are to the California Invasive Plant Council (Cal-IPC) plant profile. Cal-IPC has many resources to help assess and prioritize invasive species. They are focused on wildland rather than garden settings; however, the information in the plant profiles is still helpful in assessing invasives and choosing the best methods for control.

The UC Weed Research and Information Center (WRIC) website has lots of useful information on weeds and management methods. The site has a Weed ID tool, as well as information presented by weed species.

Cal-IPC, Cal EPA, and the UC Statewide Integrated Pest Management Program worked together to create WeedCUT (Weed Control User Tool). WeedCUT has an overview of different management practices, best management practices by species, and a decision-support tool to help users determine the best method to control different weeds. This is also geared towards wildlands but can still be helpful for us native habitat gardeners.

Another important tool is our own observations in nearby gardens and parks. Gardeners can’t help looking at plants, so we often have a good idea of what weeds are problematic in our area, how they move, and how quickly they spread. This type of local knowledge is often the most useful!

How Weeds Spread:
An important part of deciding which weed to focus on is knowing how species spread. For many species, this is knowing when it will flower and seed.  Timing can vary from year to year, and from place to place, based on weather patterns, so we need to keep an eye on the garden as soon as sunny days start to spur flowering. Ideally, we want to catch plants before they go to seed. If plants are starting to seed, it is possible to put flower heads into bags and remove them from the site, but it’s much easier to remove plants before they seed rather than trying to contain tiny seeds that want to get free. Keep in mind that some species’ seeds are known to persist in the soil for decades (broom, again!), so getting a plant out before it sets seeds is crucial. There are some invasive species which can flower and seed multiple times each year, panic veldtgrass being a notable one, and a different strategy is needed for these species. They can be worked on throughout the year to gradually reduce and control the population. 

English ivy smothering native ferns
Photo by Caroline Christman

Some of the most challenging invasive species spread vegetatively through rhizomes or stolons, such as English ivy (Hedera helix), periwinkle (Vinca major),  and Bermuda grass (Cynodon dactylon). These plants flower and spread via seed as well, but their vegetative spread may be the hardest to control. Because they are difficult to remove once established, it is important to remove young plants when they are first seen in the spring. Removing a mat of English ivy is a large task we can undertake later in the year once the spring and summer seeders are under control. 

Weed Control Methods:
There are numerous methods used for control depending on species, location, slope, soil type, time of year, resources available and more. The WeedCUT tool mentioned above is a good place to see a broad range of options. For the smaller native garden, some of the easiest methods available to us are hand removal; brushcutting; and covering areas with mulch or tarp. There is some overlap between these methods and many, many variations on how to use them.

Weed Wrenches

Weed Wrenches

Hand or Manual Removal. This is the method we were using, as described above, to remove thistles, bur clover, and panic veldtgrass. In winter and spring, when the soil is still moist and easy to dig, this approach works well. This is the most targeted method and the most certain, as we can ensure that the root is removed and the plant will not return. However, hand removal is time consuming when there is a lot of ground to cover.  Any number of hand-held tools are available; we can choose between hoes, shovels, spades, handpicks, digging knives, weed wrenches, etc. Different tools are good for different species and soils: a handpick or digging knife is good when it’s important to get out a long tap root, and a weed wrench is needed for getting larger species such as broom or cotoneaster (Cotoneaster pannosus). (Marin CNPS Chapter lends out small and large weed wrenches.) Pruning shears can be used to cut herbaceous plants, such as annual grasses – this is a nice option to use around new plantings where many small weeds come up and digging each one out is overkill. Hand weeding is also fun to do together- we can grab a few gardening friends and weed together!

Brushcutting. A brushcutter or weed whip can be a great way to cut back larger areas of weedy grasses and forbs. This method allows control over how much material to leave above the soil surface, so we can leave 3 or 4 inches of stem to act as erosion control. When using power-tools it is important to keep in mind user safety, fire safety, and the potential to harm animals hiding in the vegetation. Before brush cutting an area, walk through and make sure there are no bird nests or wildlife. See WeedCUT for more information: Cutting: String Trimmers / Brush Cutters

Sheet mulching

Covering. Covering areas with mulch, sheet mulch, or tarp is another option to consider. On a small scale, mulch can be used to cover areas around new plantings and reduce the amount of hand weeding needed while also holding in soil moisture. There are many potential mulches to use, wood chips being the most common. When choosing mulch, make sure you are not introducing weed seeds (choose rice straw rather than hay) and consider fire safety.  Sheet mulching (placing cardboard or heavy-duty paper covered with a layer of mulch) and tarping can also be used on a larger scale in areas dominated by weedy plants. We start this process by cutting plants back to the soil surface. For annual or biennial plants, covering for a few months during the growing season may be enough. For perennial plants with more energy stored in their roots, covering will probably need to be maintained for a year or longer, and still may not work depending on the weed species. When choosing to cover an area, we need to keep in mind that on-going maintenance is required to keep the cover in place and intact, and to remove any new growth coming up around the edges. Also note that long-term coverage will prevent the growth of any native plants in the seed bed. Tarping, which may be more effective to kill weeds than mulching, will also increase soil temperatures and may harm soil biota. See WeedCUT for more information on tarping: https://weedcut-new.ipm.ucanr.edu/management-practices/tarping/

Disposing of Weeds:
If weeds are removed prior to setting seed, we can keep them in the garden, adding them to a compost pile or bin, cutting them up to be used for mulch, or allowing them to decompose on site.  Home compost piles are not hot enough to kill seeds, so any seed-bearing material should be added to the green bin to be composted at an industrial facility and kept out of the garden. Some plants are able to sprout from stems, think periwinkle and Cape ivy (Delairea odorata), and the biomass should be taken out of the garden to reduce the chance of starting a new infestation.

This is just the tip of the weed control iceberg, and there is no one right answer for any weed management issue. Weed control, like gardening, is a process which takes time and experience, and lots of trial and error. It can be a lot of work, so don’t go it alone! Join us in the Marin CNPS Gardening Group and look for upcoming Marin CNPS or other gardening events to meet other gardeners.  Gardening together gets more than twice as much as done and is more than twice the fun!

Please share your stories, tips, and tricks for weed control to help other habitat gardeners! Send them to Ann Elliott.

California Native Ferns

California Native Ferns

Gardening with Natives

Caroline Christman

Lady Fern – Athyrium filix-fimina
Photo by Caroline Christman

Winter in California is a magical time. After the dry days of autumn, rain returns and a wave of green covers the landscape. Once golden-brown hills seem to grow a green stubble overnight, and even the cool, shady forests are transformed by lush young foliage. A walk in a coast redwood or Douglas-fir forest, or even around the neighborhood, is an opportunity to see beautiful plants emerging. One plant group that shines especially bright in the winter is our native California ferns.

California polypody emerging from the hillside Photo by Caroline Christman

Ferns are Pteridophytes, members of a group of ancient vascular plants which evolved before gymnosperms (such as conifers) or angiosperms (flowering plants). They reproduce via spores produced on the underside of leaves in structures called sporangia, which often are grouped together into visible sori. Most ferns grow from rhizomes, an underground stem, which can survive disturbance and hot, dry periods. During the wet winter months new fronds emerge from the rhizome with the characteristic fiddlehead. These unravel into intricate, delicate green fronds that are sure signs of spring approaching.

The delicate appearance of ferns belies their true hardiness. In my Sausalito neighborhood, I see ferns unfurling from steep road cuts, near shaded building foundations, from amongst solid expanses of English ivy, and pretty much anywhere that is moist. In the garden, tough native ferns can be a substantial component of the understory, cover steep slopes, protect creek banks, or be grown in a pot to brighten up a deck or shady entryway. 

Giant Chain Fern only slightly nibbled
Photo by Caroline Christman

Ferns bring a dazzling array of vibrant greens to the garden. The attractive foliage provides protective cover for birds, insects, and other small wildlife as well as being an important food source for butterflies and moths. Ferns are generally not a favorite food for deer, but young fronds may be nibbled when other food sources are limited. Ferns can either grow in clumps from a central point, such as Western sword fern, or form spreading colonies. California polypody ferns send up single fronds along their rhizome to create a low-growing fern blanket. Because most ferns grow from rhizomes, they can easily be divided to expand your fern understory or share with a neighbor.

Polystichum munitum – Western sword fern
Photo by Ann Elliott

There are many species of fern native to Marin. A walk around your neighborhood or local park is a great way to see which species do well in your area. In considering adding ferns to your garden, it’s important to note that some ferns are semi- or completely deciduous (summer or winter), and this will vary depending on growing conditions. For example, the same species of fern may be summer deciduous in sunnier or dryer conditions and will not be summer deciduous in shadier or moister spots. Most ferns prefer shady, moist locations, but some are more drought and sun tolerant than others. 

Below are some common native ferns for the Marin garden. Each species name is linked to the Calscape page, which has more species information as well as nurseries which carry them. The spring Marin CNPS native plant sale (online plant sale April 3-6) is a great place to purchase plants and chat with experienced native plant gardeners. If you can’t make it to the CNPS plant sale, try local nurseries which specialize in native plants, including ferns, such as  California Native Landscape (CNL) Nursery in Mill Valley and O’Donnell’s Nursery in Fairfax. 

Blechnum spicant – deer fern
Photo by Ann Elliott

Dryopteris arguta – coastal wood fern Ann Elliott

Evergreen or Semi-evergreen Ferns

Western Sword Fern (Polystichum munitum): This large, upright fern has dark green foliage and does well beneath a dense canopy. It prefers shade and moisture, and in dryer conditions is semi-deciduous in summer and more prone to thrips infestations. It grows in clumps and does not spread quickly.
Deer Fern (Blechnum spicant): This small, upright fern prefers moist, cool conditions. It has two types of fronds, sterile fronds which arch out from the center and fertile fronds which grow straight up and die back in fall/winter. It grows in clumps and does not spread quickly.
Coastal Wood Fern (Dryopteris arguta): This small fern is more drought tolerant than other ferns and can grow in somewhat sunnier and dryer conditions. It can often be found on woodland slopes. Fronds grow in clusters, but can spread to form colonies. This species can be hard to find in nurseries, other ferns in the genus Dryopteris may be available.
Giant Chain Fern (Woodwardia fimbriata): This is the largest fern in North America. Its graceful arching fronds are the perfect adornment in partial or deeper shade. Performing best with regular water, it grows in clumps and does not spread quickly.

Lady Fern emerging from the roadcut
Photo by Caroline Christman

Deciduous Ferns


Lady Fern (Athyrium filix-femina): This large, lacy fern is winter deciduous with bright green fronds bursting forth in early spring. It grows in round clumps and can spread to form colonies in moist soil.
California Polypody Fern (Polypodium californicum): This small fern is summer deciduous but makes a great winter groundcover. It does well on steep slopes and, if happy, will spread slowly to form a colony.

These are just six of our lovely native ferns, and there are many more not included here. With ferns of varying sizes, growth habits, and spreading propensity to choose from, there is likely a good fern for any shady or moist spot in the garden.

We want to hear about your native habitat gardening experiences! Please send writing, photos, tips, or questions to Ann Elliott for inclusion in the next newsletter.

Additional Resources:

Selecting Ferns for the Garden
Gardenia.net: Recommended Native Ferns for the Northern California Coast
Pacific Horticulture: California Native Ferns
Calscape Fern List

Fern Ecology
US Forest Service: Fern Structure
American Fern Society
Pteridophyte Collections Consortium
Ferns Past and Present
Introduction to Ferns
Bay Nature: Fantastic Ferns and Where to Find Them

Flowering Currant

Flowering Currant

Ribes sanguineum
Photo by Caroline Christman

Gardening with Natives

Caroline Christman

If you have a shady spot in the garden to fill, look no further than the flowering currant. Ribes sanguineum and R. sanguineum var. glutinosum are wonderful plants for the Marin habitat garden; they are beautiful, easy to care for, and provide food for a wide variety of native birds and insects. They are also readily available at many nurseries and local plant sales.

Although winter deciduous, flowering currants add interest to the garden all year round. They have an upright growth habit, creating an elegant form that gradually expands to create a vase-shaped shrub up to 10 ft high and 6 ft wide. They are great as a foundation plant along edges, fence lines, or in corners, providing a structural element and backdrop to lower growing plants. In winter, leaves drop to reveal delicate branches. Soon after, pendant pink flowers emerge like hanging chandeliers to brighten shady nooks and attract pollinators. Soft green foliage begins to grow in spring as the flowers fade.

Flowering currants are drought-tolerant in coastal zones. They do well in shade or part shade, such as under oaks or bay laurel, in north or east-facing areas of the garden, or along the outer edges of a riparian corridor (as long as their feet are not wet and soil drains well). They also can do well in more acidic soil under conifers. Once established in a shady spot, they will generally not need summer water. However, if planted in full sun or areas with hotter summer and fall conditions, summer water may be needed.

Ribes sanguineum bush
Photo by Caroline Christman

The entire flowering currant plant has habitat value for native wildlife. In winter and spring flowers provide nectar for hummingbirds and butterflies (including Monarchs). Later in the year berries are a food source for a variety of birds and small mammals and foliage is eaten by caterpillars. Deer will also browse on currant foliage, so netting or protection of some kind may help young plants get established.
In my walks around Sausalito, I visit this flowering currant in an east-facing garden under coast live oak and bay laurel. It is on the boundary between two houses, and though both gardens have recently been redone, the flowering currant has been saved. I like to think it is an inspiration, as the houses on either side have added native plants to their gardens. In all seasons, it beckons to me; as I round the corner and catch my first glimpse of pink flowers or the smudge of distinctive green it brings a smile to my face.
See more about R. sanguineum and R. sanguineum var. glutinosum at Calscape.

Do you have stories, tips, or photos from your garden that you’d like to share? Please send these to Ann Elliott for inclusion in an upcoming Marin CNPS Newsletter.