California is host to almost 7000 species of native plants, more than any other state. About 40% of those species are found only in California. In fact, California is more species-rich than most other places on Earth. Native plants are those that grow in the wild, have evolved in what is now California and were present here prior to contact by Europeans. As you drive down the highway, however, most of the roadside plants you see are non-native -- they were brought here either accidentally or on purpose from elsewhere. There are more than 1000 species of non-native plants present in California. Many of these are invasive and can out-compete natives where the natural habitat has been disturbed, as is the case along roadsides. The California Academy of Sciences estimates that 75% of the original habitat for native plants has been lost to non-native plants due to human activity. Imagine Table Mountain without its spring show of wildflowers, or valley grasslands devoid of California poppies!
CNPS produces many statewide publications, including Artemisia, a quarterly journal with a scientific perspective on native plant topics. The CNPS Fire Recovery Guide, published in 2019, has been widely distributed to victims of the Camp Fire and other recent fires in Butte County and is also available to download for free at the CNPS website.
CNPS has also created an online database containing horticultural information about specific native plants. Called Calscape, the database can be used to find suitable native plants for your garden based on location and desired plant characteristics. Another useful Calscape feature is a garden planner which generates a suggested plant list and sample garden designs based on answers to four simple questions. This feature is quite useful for people interested in gardening with native plants.
CNPS members affiliate with one of 35 local chapters. The Mount Lassen Chapter covers Butte, Glenn, Tehama, and Plumas Counties. Rob Schlising, retired CSU Chico biology professor, described the formation of the chapter: “Over 75 people assembled at a meeting in Chico on the rainy evening of 4 November 1977 to initiate a new chapter of the California Native Plant Society. The group chose the name “Mount Lassen Chapter,” and I was elected the first chapter president. I provided an illustrated talk called ‘What is so special about our native plants?'”
The chapter continues to have an active program which includes online presentations, field trips throughout the year, maintenance of the Alice Hecker Native Plant Garden at Chico Creek Nature Center, co-sponsorship with Altacal Audubon of the Water-Wise and Habitat-Friendly Garden Tour, and educational outreach at public events. The chapter also provides grant money for students to attend the statewide conference. Information about upcoming events is available on the chapter website. The next online presentation will be a talk about Calscape by Jessica Woodard, Calscape Product Manager, on Wednesday, September 7, 2022 at 7pm.
By Penny Pawl, U. C. Master Gardener of Napa County
Winter is a perfect time to start planning the pollinator garden you will create in the spring. Start by deciding just where you would like to put the garden. Some people have taken out the center of their lawn and created a space for a garden for pollinators.
Pollinators are extremely important to the global ecosystem. Without them, many people would starve because food plants would not get pollinated. You can help by making an area in your garden hospitable to them.
Last fall, I picked out an area in my garden and decided to line it with hardware cloth because gophers had started to pull down my precious milkweeds. I dug up those milkweeds, then a helper laid wire over the soil and used building blocks to hold the wire in place. Over the winter, my helper added various soils and compost to create an area where the plants would grow. Soil was added to the openings in the building blocks.
Meanwhile, I was researching the plants that bees, birds and butterflies love. These plants have to be full of nectar as some pollinators need nectar for daily food and others need it to store in their nests.
I especially wanted to add nectars that would attract bumblebees. I have always had bumblebees in summer, but for some unknown reason, they disappeared the previous July. This year, I found the queen feeding on purple salvia in October. The queen is much bigger than the workers and usually stays in the nest while the workers gather nectar.
My next step was to start buying seeds of the plants I wanted. As soon as the weather warmed a bit, I started the seedlings in my hothouse. I had learned that marigolds, zinnias and salvias were pollinator favorites. For me, there is nothing more enjoyable than settling down on a long winter night with a stack of seed catalogs. Our bees, butterflies and birds evolved with California native plants, so that's what I chose.
Once you determine where you want your pollinator garden you can start to prepare the area for planting. Add a mixture of compost and soil. Let these two elements mix over winter, giving ground worms and small insects a chance to start working. Ground worms sift the soil through their gut and make tunnels for water to move through.
I found that bumblebees especially love ‘Hot Lips' salvia from Mexico. They drill a hole in the back of the flower to get directly to the nectar. Honeybees also visit my garden because there are hives nearby and some of them nap for the night in the flowers.
Native bees are small and often nest in the ground or in holes in trees and other wood. They visit my garden often for nectar.
Monarch butterflies need native milkweed to raise new generations so I grow two or three different native milkweeds in my pollinator bed. Some milkweeds come back from the roots, so you plant once and they continue to produce.
Sunflowers are always a good choice. I experimented with a Mexican sunflower with small flowers using seeds I bought online. Birds and squirrels are especially fond of sunflowers so plant a variety. I added more flowering plants to the mix, and as the flowers formed seeds, I plucked them and saved the seed.
Before I planted anything, I had a one gallon-per-hour drip line laid in the bed. Once plants got established, I watered once a week. Native plants don't require a lot of water, so that schedule was sufficient. For fertilizer, I used sifted worm compost which has all the trace elements plants need.
Above all, make your pollinator garden your own creation, with plants that you love and that they will, too. The pollinators will be grateful.
Next workshop: “Citrus: Preserve It, Serve It” on Thursday, January 16, from 1 p.m. to 4 p.m., at the University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Presented by UC Master Food Preservers. For more details and online registration call 707-253-4221 or visit http://napamg.ucanr.edu.
The UC Master Gardeners of Napa County are volunteers who provide UC research-based information on home gardening and answer your questions. To find out more about upcoming programs or to ask a garden question, visit the Master Gardener website (http://napamg.ucanr.edu) or call (707) 253-4221 between 9 a.m. and noon on Mondays, Wednesdays or Fridays.
By Susanne von Rosenberg, UC Master Gardener of Napa County
Adding one or more trees to your garden can make a very big difference. Trees are amazing. They can provide shade and fruit, save energy, support wildlife and help reduce global warming.
Autumn is the best time to plant deciduous trees in Napa County, so it's not too soon to start thinking about trees you might want to add. Here are some tips and suggestions for choosing wisely.
First, know where you're planting. How much sun, shade and wind is there? Will you be planting under or near a power line? What kind of soil do you have?
Make sure you know the maximum height of the tree and how wide it is likely to get. Many a homeowner has had to make the sad decision to remove a tree that was simply too big for its location.
We love that trees provide shade, but we need them to shade the right places. It's also important to be considerate of the shade a tree might cast on neighbors' properties.
If you want to keep your house cooler, plant a tree with a wider canopy on the south, southwest or west sides of your home. You'll want your shade tree to be deciduous, so you can get the benefit of the sun in the winter.
Planting trees to shade your home will have a real pay-off. The Urban Forestry Network estimates that shade trees can reduce the need for air conditioning in homes and offices by up to 30 percent. If you don't have air conditioning, trees can simply keep your home much more livable in the summer.
The same idea applies to shade in your garden. One of my favorite places to be in the summer is in the dappled shade of a tree, reading a great book.
If you are interested in supporting wildlife, consider planting a California native tree or any tree compatible with native shrubs and other plants. Sometimes that's as easy as allowing an oak seedling that happens to be in the perfect location to grow. I have one growing in the center of my front yard. Thank you, squirrels!
If your squirrels are not as obliging, the California Native Plant Society has a lot of information on native plants. Visit the CalScape website for a listing of 186 native trees (https://calscape.org/loc-California/cat-Trees/ord-az/np-0/vw-list/page-2? ). The Napa chapter of the Society has plant sales in the spring and the fall, with plants that are particularly suited to Napa County.
If you want to plant fruit or nut trees but aren't sure how to choose the ones best for your site or how to plant and care for them, consult the Napa County Master Gardener website for advice. If you don't have a lot of space, consider coordinating with neighbors to grow a variety of fruit trees and share the harvest. Fruit trees can be kept compact through pruning and still yield a lot of fruit. They do need regular water and fertilizing, as well as plenty of sun, to produce properly.
If you're strategic in your choices, your trees can serve multiple purposes. I planted an almond tree about 30 feet from the southwest corner of my house. As it gets taller, it will provide shade. It's still a young tree, but I've already gotten some almonds. Mostly, though, my almond tree has become a living bird and squirrel feeder. Because I don't cover it with netting, my animal friends get most of the almonds before I do. I love watching them play in the tree.
Even if you don't need another tree, there are environmental reasons to plant a few. According to the Urban Forestry Network, if every American family planted just one tree, the amount of carbon dioxide in the atmosphere would drop by one billion pounds annually. (You read that correctly.). That's nearly 5 percent of what we humans generate each year.
What's more, a mature tree can release enough oxygen to support two people. A recent study published in the journal Nature suggests that if humans planted forests on all available suitable land (terrain that can support trees and is not currently used by humans), we would compensate for almost all of the extra carbon we have put into the atmosphere since the Industrial Age. You can read the story here: https://www.scientificamerican.com/article/massive-forest-restoration-could-greatly-slow-global-warming/?utm_source=pocket-newtab.
What kind of tree are you going to plant?
Next workshop: “Cool-Season Vegetables: Now is the Time to Plan and Start” on Saturday, August 10, from 9:30 to 11:30 a.m., at the University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Repeated on Sunday, August 11, from 1 p.m. to 3 p.m. in Yountville. For more details & online registration for the Napa workshop: http://napamg.ucanr.edu. Or call 707-253-4221. For the Yountville workshop, go to Online Yountville registration or telephone the Parks & Recreation Department at 707-944-8712.
The UC Master Gardeners are volunteers who provide UC research-based information on home gardening and answer your questions. To find out more about upcoming programs or to ask a garden question, visit the Master Gardener website (http://napamg.ucanr.edu) or call (707) 253-4221 between 9 a.m. and noon on Mondays, Wednesdays or Fridays.
By Penny Pawl, U. C. Master Gardener of Napa County
I can feel spring in the air, so it is time to think about which unique, beautiful plants I can add to my garden. As I peruse all the new garden and seed catalogs, I need to remember not to choose any invasive plants.
Many plants in American gardens and natural landscapes have come from another country. Over time, they have really made themselves at home. If you plant them, some of these imports will take over and crowd out native plants.
In Napa Valley, volunteers have had to remove Spanish broom from a local park. Spanish broom has bright yellow flowers and can take over a landscape in a few years.
Many plants become invasive because nothing keeps them in check. The wild mustard in Napa Valley is a good example. It is beautiful but an opportunist, and here it has found perfect growing conditions.
My neighbor planted a beautiful grass with small seedpods. In a short time, the grass was coming up all over their yard. Then it moved to mine. It was easy to pull, but when a seed went up their dog's nose, they pulled the grass out.
A fellow Napa County Master Gardener had a beautiful wisteria. I love this plant and admired hers which was growing on both sides of her 100-year-old house. The vine had grown under one side of the house and come up on the other. No wonder it is on the invasive-plant list.
When my husband and I were new home owners, he planted a weeping willow. He sited it many feet from our well and our home, but its roots advanced quickly toward us. It had to go.
Another neighbor had a beautiful stand of giant bamboo in front of the home. It even bloomed one year and looked wonderful. But then it spread under the house's foundation. Bamboo has a life of it' own and is extremely invasive. In Hawaii, it is everywhere but it is not a native.
One of the most invasive plants is the wild oat (Avena fatua L.). I hand weeded an area of my yard overrun by this plant. It took time but I vanquished it. The following year it did not return, but in two years, there it was again.
I also fell in love with Santa Barbara daisy (Erigeron karvinskianus), also known as fleabane. It comes from Mexico and down the coast of South America. I planted a few small plants that very quickly took over the beds. It had to go. There are natives in the same family that are not such thugs.
The California Invasive Plant Council maintains a list of the most invasive plants in California (http://www.cal-ipc.org/ ). Although nurseries still sell them, these plants threaten natives by competing for water and nutrients. These plants include big periwinkle, English ivy, giant reed, iceplant, onion grass, pampas grass, red sesbania, Russian olive and tree of heaven. Scotch broom and French broom have pretty flowers but they cause changes in the soil and shade out natives. And they produce many seeds that birds move around.
Most of these plants were imported in the 1800s for landscape gardens. The plants decided they liked it here and have moved to many areas where they are not wanted.
If you don't know what to plant, pick a California native. Natives have evolved to thrive in our soil and climate without producing rampant growth. Because they are adapted to California, most do not need much water to survive.
By T. Eric Nightingale, UC Master Gardener of Napa County
When it comes to making decisions about new plants for your garden, consider combinations of the following types: California natives, plants that aid pollinating insects and plants that attract beneficial insects.
Including native plants in our gardens should be standard practice in California. We are lucky enough to have a wider variety of ecosystems, and a more diverse range of native plants, than any other state.
California's beauty is something to be preserved and nurtured, which we can do through gardening with natives. When you add native plants to your garden you help not only yourself (they are attractive and easy to manage), but the entire local ecosystem.
Birds and other wildlife have evolved in conjunction with certain plants; they require these plants for food and shelter. Many of the popular non-native plants don't fulfill these functions.
Stepping away from the familiar classics can be difficult. Many people's image of the "ideal garden" includes plants brought here from other continents. Hydrangeas come from Asia; lavender is native to Europe. Even the locally popular agapanthus hails from South Africa.
While working in a nursery, I once had a South African customer erupt into laughter. "That is a weed!” he exclaimed, pointing to the agapanthus. “It is despised where I come from." Obviously, there is room for interpretation in what defines an ideal garden.
If you are a novice native-plant gardener, I suggest starting with one of my favorites: monkeyflower. These plants bloom throughout the spring and summer and are fairly low maintenance. The most common bloom colors are yellow, orange and red, but pink and purple can be found as well. Interestingly, there are both drought-tolerant monkeyflowers (Diplacus spp.) and water-loving ones (Mimulus spp). Both types attract pollinators but different ones. Bees seem to prefer monkeyflowers with pink blossoms; hummingbirds prefer red-flowered varieties.
Also consider California gooseberries and currents (Ribes spp.). These fall-blooming shrubs produce unique flowers that hummingbirds frequent and berries that birds enjoy. Gooseberries have thorns while currants do not. The fruit is edible but can often be bitter. The best-tasting varieties are Ribes aureum and Ribes rubrum. Aesthetically speaking, my personal favorite is Ribes speciosum, or fuchsia-flowering gooseberry. The red hanging flowers give the shrub a colorful fringed look, a unique and eye-catching addition to any garden.
One California native that helps both pollinating and beneficial insects is milkweed. Our Napa-native varieties are showy milkweed (Asclepias speciosa) and narrow-leaved milkweed (Asclepias fasciculation). You may know that monarch butterflies only lay their eggs on milkweed. Compounds in the milkweed help to feed and protect the caterpillars after they hatch.
Urban development has destroyed much of the native landscape, causing monarch populations to decline dramatically. Planting milkweed will benefit these beloved insects. What's more, milkweed flowers produce a nutritious nectar that honeybees collect, improving their health and productivity. In addition, many beneficial insects are attracted to Asclepias.
Yes, there are good bugs in your garden. The most recognizable are lady beetles, but lacewings, syrphid flies and parasitic wasps also do good work. And spiders are among the most helpful denizens of your garden. One spider can eat around two thousand insects in a year. Just think about how much free extermination work you are getting from all those arachnids. Next time you see a spider, or any unknown insect for that matter, think before you squish it. It may be a new friend.
If you are looking for more information on native plants, plan to attend the Master Gardener workshop on Sept 23 (details below). You can also find beautiful natives for your garden at the upcoming California Native Plant Society Sale on October 7 and October 8 at Skyline Park in Napa.
Workshop: UC Master Gardeners of Napa County will host a guided walk and talk on “Pollinators, Native Plants and Beneficials” on Saturday, September 23, from 9:30 a.m. to 11:30 a.m. at the Martha Walker Garden at Skyline Park in Napa. Any discussion of pollinators would not be complete without some remarks on the bounty of beneficial insects found in everyone's garden. Come see if you can recognize some pollinators and beneficial insects. Online registration (credit card only); Mail-in form (cash or check only)
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.