Creating Native Plant Habitats at Home
Early Residential Growth in Marin
Residential areas in Marin expanded dramatically following construction of the Golden Gate Bridge in 1937. In the ensuing three decades, many Marin residents created spacious gardens, often featuring large lawns and few native plants.
During the 1960s, public interest in native plants began to grow in the Bay Area. In Berkeley, residents organized a drive to save Tilden Park’s native plant garden. They eventually founded the California Native Plant Society, an organization dedicated to the preservation and restoration of the state’s native plants. In subsequent years, home gardeners have become increasingly interested in including native plants in their yards.
The move to create native plant habitat in residential spaces gained additional momentum in 2022, when the Marin County Board of Supervisors passed a resolution stating that “the UC Marin Master Gardeners, Marin Monarch Working Group, and the Marin Agriculture Department should collaboratively engage in educating homeowners and home gardeners about creating pollinator gardens including habitat for the monarch butterflies.“
It’s not hard to start planting natives in your own yard. Read on to get some ideas and find answers to your questions.
Pollinator Gardens and Monarch Waystations
What are pollinators and why are they important?
Pollinator animals depend on pollen for protein and other nutrients, and nectar for energy. As they move among plants consuming these nutrients, they coincidentally transfer pollen from flower to flower, providing the pollination services needed by plants.
Pollinators include bees, butterflies, beetles, moths, hummingbirds, and, yes, bats.
Nearly three quarters of the world’s flowering plants require a pollinator to reproduce, as do two thirds of crop plants that produce our food.
Not all pollinators are gorgeous! This is a hoary bat.
What is the difference between a pollinator garden and a monarch butterfly waystation?
A pollinator garden includes plants designed to attract and support pollinators, including bees, butterflies, and hummingbirds. These plants can include annuals as well as perennials. Shrubs and bushes can also act as pollinator plants.
A monarch butterfly waystation is a special type of pollinator garden that provides a place for monarchs to rest, refuel, and lay eggs during their migration journey. Monarch waystations are good habitats for other pollinators too.
To establish a monarch butterfly waystation, you will need to plant clusters of nectar plants — preferably California natives — suitable for the conditions in your garden. Another key ingredient is milkweed plants for the monarchs to lay eggs on and for the hungry hungry caterpillars to eat. MMWG recommends that you plant narrow-leaf or showy milkweed rather than tropical milkweed, which is more likely to house OE parasites harmful to the caterpillars (see more information on this in FAQ section below).
I want to start a monarch waystation.
How do I decide what to plant?
First consider how much sun your plants will get each day throughout the year. Marin has many different ecosystems, with plants adapted for sun, shade, and conditions in between. Many California natives are sun-lovers, so try to take advantage of sunny spots if you have them. Don’t worry if your garden space is partially shaded — just look for plants that tolerate partially shady conditions.
Beyond that, you need to think about the amount of space you have relative to the dimensions of each plant. Even a small space can be transformed into a garden that nurtures pollinators moving through your neighborhood.
A fun way to select plants appropriate for your garden space is to visit some native plant nurseries in your area, or look at the plant lists provided by the Marin Chapter of the California Native Plant Society. They even have a page to show you when each plant starts blooming so that you can have flowers all year round. Another helpful guide to choosing plants is Calscape’s Bay Area Garden Planner. For more ideas about creating a monarch waystation read this article by Marin Master Gardener Alice Cason.
The images below were taken by Marcia Basalla and include Pink flowering currant, De la Mina lilac verbena, Cleveland sage “Pozo blue”, Coast buckwheat, Narrowleaf milkweed, California aster, Yarrow, Coyote bush, Gumplant.
When you create a pollinator garden or a monarch waystation, you are contributing to a wildlife corridor. Your garden becomes a link in a chain of habitats sprinkled across open and urban spaces as well as agricultural land. Monarchs are able to hopscotch across these areas as they move through their migration cycle.
Marin Butterflies and their Host Plants!
These 24 beautiful butterflies are all found in Marin. Some non-native plants support butterflies, but native plants serve as host plants for 10-100 times more insects than non-native plants. This handout identifies the best native host plants for each of these butterflies.
Click to download this informative butterfly handout!
Two Slightly Boring but Important Components of Soil: Compost and Mulch
It’s hard to make the topic of soil seem interesting, but this seven-minute video by the California Water Board is hilarious! Watch it to learn about what makes soil healthy and to understand the benefits of healthy soil for your garden.
When gardeners prepare the soil before planting, the plants will subsequently flourish with little need for fertilizers or pesticides.
MULCH refers to material used to cover the soil surface. The most popular forms of mulch are wood chips, shavings, or bark. Other mulches include seaweed, pine needles, pine cones, hay, straw, cocoa, rice, buckwheat hulls, tree leaves, and grass clippings.
A second type of mulch includes biodegradable geotextiles like cardboard and newspaper. In contrast, synthetic mulches such as rubber and plastic sheeting do not decompose, and eventually break down into microplastics that contaminate the environment.
A third type of mulch includes materials that are natural but not degradable, such as crushed seashells, gravel, pebbles, stone chips, and slate.
For more on mulch, take a look at this table prepared by Marin Master Gardeners.
COMPOST is a key component of health soil. Compost is made of nitrogen and carbon rich materials such as leaves, grass clippings, manure, and kitchen scraps. Over time, this organic mixture naturally breaks down — or decomposes — and becomes a rich, dark substance ideal for nurturing plants. The ultimate form of recycling, composting returns organic nutrients back to the soil in a form readily absorbed by plants.
Compost loosens up the dense texture of heavy clay soils. It improves sandy soils because organic matter holds water and nutrients better, so the sandy soil does not wash away as quickly.
Organic mulch (Photo: GardenSoft)
Pebble mulch
Sheet mulching involves compost and mulch, and is a good way to improve your soil, attract beneficial bacteria and earthworms, and slow down the growth of weeds.
The basic process is to first add a layer of weeds or grass on top of the soil, then a barrier of cardboard or newspaper, followed by compost, and topped off by a layer of mulch. Now you know why it is also called lasagna gardening….the number of layers is up to the cook, but the image below captures the essence of the recipe.
If you become a sheet mulch aficionado, you can refine this basic recipe in innumerable ways. For more information, read this article by Martha Proctor, a Marin Master Gardener, and this one by Charlotte Torgovitsky.
And Now for the Water
Systems for watering plants can range from the very simple to the very complex. Each system has its pros and cons. Here are the basic options:
Hand water with hose or watering can
Install drip systems in which water goes directly into the soil from small emitters placed near each plant or from an emitter line
Lay a soaker hoses made of porous material on top of the ground that allows water to seep out along the length of the hose.
Use spray or sprinkler systems
For more details, take a look at this article by the Marin Master Gardeners, as well as others on their website.
Overall, drip irrigation is typically seen as the best system for conserving water. The water goes where it is needed, not into the air. Drip systems are slow, so water will not run off the surface of clay soil and will remain longer in sandy soil. Drip irrigation also delivers water to the plant’s roots, encouraging their growth and it does not water the weeds.
On the downside, it can be a headache to move drip systems when gardeners want to make changes to their plantings. New plants may end up alongside more established ones with dissimilar water needs. And it is possible to accidentally damage a tube with a shovel or for a tube to become a chew toy for a gopher or curious pet.
Water should also be provided for the monarchs!
Birds and insects of all kinds need water to survive, so it is a good idea to include a source of water in your home garden. There are many options to choose from, but you don’t need to get fancy. A shallow container of water will do the trick.
Monarchs and other butterflies need moisture but cannot land on water to drink. Instead, they sip liquid from muddy soil, benefitting not only from the water but also absorbing minerals from the soil. This behavior is called “puddling.”
Create a puddling area by digging a wide, shallow depression in the ground and lining it with pond liner. Or just use a shallow dish, adding a 1-2 inch layer of landscape sand mixed with soil along with just enough water to keep it wet. You can also put in a few rocks to serve as a landing and basking area.
Monarchs and mud (photo: Xerces society)
Basic backyard puddling area
FAQs: Monarchs and Native Plants in Home Gardens
Can I help the monarchs by raising them in captivity and releasing them?
As the number of monarchs drops lower and lower, it may seem reasonable to breed them in captivity, with the goal of releasing them as adults. But the answer is no, don’t do it. The Xerces Society and other monarch groups have concluded that the risks of captive breeding are greater than the benefits. Monarchs reared in captivity are more susceptible to parasites, which they can also spread to wild monarchs. Also, continuous breeding over generations can dilute genetic diversity, undermining monarchs’ ongoing adaptation to their environment.
Captive rearing of wildlife is illegal in California. California law (Fish and Game Section 1002) prohibits the taking or possession of wildlife for scientific research, education, or propagation purposes without a valid Scientific Collection Permit (SCP) issued by CDFW.
Is milkweed poisonous to animals or humans?
Milkweed contains toxins (cardiac glycosides or cardenolides), some species of which can be toxic to animals if consumed in large quantities. Fortunately, milkweed tastes terrible (unless you are a monarch caterpillar). Livestock and wild animals don’t eat it unless there are few other foraging choices. If you have milkweed in your home garden, it is unlikely that your pets will sample it. To be on the safe side, teach children not to put it in their mouth. Also, avoid touching your eyes if you have been in contact with milkweed; the toxic sap can cause intense inflammation.
Bear in mind that other common landscaping plants are also poisonous, and similar precautions are warranted. This includes the leaves of foxgloves and hydrangeas, berries of lantana, and all parts of summer-blooming oleander. Read more in this article from the Marin Master Gardeners.
Why are there bugs on my milkweed plants? Are they harmful?
You may not be happy to find anything other than a monarch caterpillar feeding on your milkweed plants. However, in small numbers, insects other than monarch caterpillars are not harmful to the plant. They typically suck the sap from leaves, stems and seed pods but this usually does not kill the plant.
When you see bugs on your milkweed, don’t spray them with any kind of herbicide. Whatever would kill them is also likely to kill monarch caterpillars. Sometimes people are tempted to blast the insects with a strong spray of water, but in doing so they risk dislodging the monarch caterpillars too. Instead, have faith that natural enemies — like lady beetles, lacewings, syphid flies, and parasitoid wasps — will come in and manage the population of bugs eating your milkweed.
What kind of milkweed makes the best monarch habitat for home gardens in Marin?
The best option for a garden that is at least one mile from the coast or the Bay is narrow-leaf milkweed (Asclepias fascicularis), which is a native of Marin. Showy milkweed (Asclepias speciosa), is a California native and has been in Marin for a long time, and so is acceptable in urban and suburban gardens. Both types of milkweed go dormant in the fall, prompting monarch butterflies to head west toward an overwintering site.
A third species, tropical milkweed (Asclepias curassavica) should not be planted. It has attractive blossoms and doesn’t die back in the winter. But it is not native and its longevity encourages butterflies to linger inland rather than migrate to overwintering habitats. Tropical milkweed is also more likely than the native species to carry deadly parasites. To learn more, read this article from the Xerces Society for Invertebrate Conservation as well as this one from Monarch Joint Venture.
The CA Department of Food and Agriculture has designated tropical milkweed as a B-rated noxious weed and in 2022, Marin County banned the sale of tropical milkweed in nurseries.
I live on the coast. Can I plant milkweed?
The most recent guidelines from the Xerces Society advise against planting milkweed if you live within one mile of the coast or the San Francisco Bay. If monarchs encounter milkweed when they are overwintering along the coast or the bay, it will stimulate them to breed and lay eggs. This depletes their ability to survive the winter. Additionally, in the colder coastal weather, their eggs are less likely to survive and turn into caterpillars. If you live near the coast or the bay, you can cultivate native nectar plants but not milkweed.
Can I carefully bring monarch eggs or caterpillars inside to rear them in safety?
As with captive breeding, monarch experts advise against bringing in monarch eggs and caterpillars from your garden.
Impaired population fitness: If you collect and hand rear 100 eggs, 90 of them may survive to adulthood instead of the 10 that would have survived on their own in the wild. But maybe some of those 90 eggs wouldn’t have survived on their own because they’re not as “fit” (in the biological sense) and now their less-fit genes are out there in the population.
Resource limitation: Let’s say you release 90 butterflies instead of the 10 which would have survived on their own. It is likely that there will not be enough milkweed for 90 caterpillars to eat.
Susceptibility to disease: When monarchs are reared in densities greater than typically occur in the wild, they are much more prone to diseases and infections from pathogens like the protozoan parasite OE.
If you want to read more about captive rearing, take a look at this article by Emma Felton of the Xerces Society.
I don’t have a large area for plants. What can I do to help pollinators?
Even a few plants will help pollinators. You can grow plants in pots or window boxes.
Another option is to make use of your “hellstrip” — the narrow dirt patch between the edge of the sidewalk and the curb. Reflected heat, foot traffic, poor soil, and irrigation obstacles pose challenges, and they are often home to weeds, dog poop, and wind-blown trash. Do a hellstrip cleanup, put some hearty natives in the space, and see if you can attract some pollinators.
Check out the Marin Chapter California Native Plant Society website to find out which native plants are right for your area.
