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.
If you are looking for attractive and low-maintenance additions to your garden, look no further than California native plants.
Most of California falls within a zone known as the California Floristic Province. Defined by the Sierra Nevada range on the west, this area is considered to be a biodiversity hotspot. Its many types of terrain and climate have given rise to around 8,000 endemic plant species. Consequently, you have many choices for native plants in your garden, whether you are looking for a delicate flower such as the California poppy or a tough survivor like manzanita.
Native plants offer numerous benefits. Many are drought tolerant, a popular attribute in recent years. However, even drought-tolerant plants need some water until they're established. Deep watering the first year will encourage deep root growth so the plant can access the water it needs in the future. This early attention will pay off by saving you time and money for years to come.
While native plants enhance your landscape, they also provide food and shelter for local wildlife. Many birds relish their berries and seeds and use them for perching while hunting insects, hiding from predators and nesting. Development has removed large amounts of native habitat, but as gardeners, we can help by recreating those living spaces in our own yards.
Native bees will also feel at home in a garden filled with California natives. They pollinate plants (especially important if you are growing edibles) and are a food source for birds and lizards. Most native bees do not sting unless provoked, and they do not form large colonies, so there are no nests or swarms to manage.
One iconic Napa Valley native is the majestic oak. We have nine native species here, but the most common are the coast live oak, the scrub oak and the valley oak. "Live" means the tree is evergreen. It is impossible to travel around the valley without noticing their beauty.
Often I have accidentally come upon an oak, approaching it at such an angle that its full shape is suddenly visible. I am awed by its beauty. The thick, continually branching arms stretch to the sky, as if holding it aloft. From a distance, the blanket of waxy leaves appears soft and fluffy. These are unique trees that, as natives, require particular care.
Like many native plants, oaks are drought tolerant, which means that they are sensitive to over watering. They do not want any summer water, so irrigation lines or plants with high water needs should not be placed under them.
While the effects of too much water are not immediately visible, long-term over-watering can kill an oak tree. Mulching around the base is also discouraged. The leaves and other litter that drop from the tree, if left alone, will naturally prevent weeds from sprouting and also return nutrients to the soil.
You can learn more about native plants on the California Native Plant Society web page. There you will find lists of plants native to Napa Valley and nurseries that stock them. The society holds twice-yearly plant sales where you can learn more about California native plants.
Workshop: U. C. Master Gardeners of Napa County will host a workshop on “Oaks and Natives” on Saturday, May 13, from 9 a.m. to 11 a.m., at Skyline Park, 2201 Imola Avenue, Napa. Enjoy a guided tour around the park to appreciate and learn about oak woodlands and the stresses they face. Then continue with a stroll in the Martha Walker Garden to see oaks and native plants in a garden habitat. Learn about plant care and using native plants under oaks and elsewhere in your own garden. Take advantage of this opportunity to enjoy two of Napa County's woodland gems. Online registration (credit card 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
As the rain subsides and the weather warms, spring finally become visible on the horizon. That means our time to get into the garden is drawing near.
Many of us, however, are looking at our winter-ravaged gardens and wondering where to start. If you have been braving the elements to tend your garden, you will probably be thrilled to begin spring garden duties. For the rest of us, however, spring garden prep can be daunting.
Where to begin? In our little garden, my wife and I will start with cleaning up leaves and other debris. This will not only improve the aesthetics, but it will also have a dramatic effect on the garden's health and on pest management. While a thick layer of leaves can act as compost, it also provides a cozy living space for snails and slugs, rodents, insects and fungus. During cleanup, we can also look for any problem areas or damaged plants that need attention.
Next up is everyone's favorite chore: weeding. Don't put this off. It is important to pull weeds before they go to seed and become an even bigger problem.
Then it is time to plan any new plantings. Planting in wet soil is not recommended, so check now for areas that may have drainage issues. Overly saturated soil will look black and have a rotten odor. If you find such a spot in your garden, leave it bare and let the sun evaporate some of the excess moisture. During any upcoming rainy periods, cover the area with plastic sheeting to prevent the problem from worsening. Remove the plastic on sunny days to let the water continue to evaporate.
Should your soil feel dry (unlikely given the amount of rain we've had) or at an acceptable hydration level, cover with a layer of compost or mulch. This material will improve moisture retention through the summer and improve soil tilth and biotic health. Good mulching practices can make a world of difference when it comes time to dig that tough Napa soil.
If you are planning to plant vegetables, early February is the perfect time to get some of them started. Broccoli, cauliflower, eggplant, kale, peppers, onion, peas, lettuce and tomatoes will all benefit from an early start inside your home or greenhouse. Sowing times vary by variety, so be sure to follow the instructions on the seed packet.
If you don't have a seed-starting tray and warming mat, consider investing in one. The extra warmth can reduce germination time considerably. When you are not starting seedlings, you can also use the kit to improve your results for any cuttings you want to propagate.
Thinking of adding some ornamental plants but not sure which ones to choose? Consider California natives. The benefits are myriad, but to me, their best attribute is the low amount of care they require once established.
Plants adapted to the regional climate are generally more drought tolerant, making them an easy choice for low-maintenance landscaping. Some personal favorites include the Matilija poppy (Romneya trichocalyx) and Ceonothus ‘Dark Star' (also called California lilac). Both have attractive flowers that enhance any garden.
Should you wish to attract hummingbirds, I recommend California fuchsia (Epilobium canum), scarlet monkey flower (Mimulus cardinalis) and hummingbird sage (Salvia spathacea). The blooms of the California fuchsia persist well past those of many other flowering plants and can be relied upon to add a splash of vibrant red to a fall landscape.
Finally, don't let this winter's wet weather fool you into thinking that drought is a thing of the past. Southern California is still considered to be in drought conditions. Ground-water levels across the state continue to be a concern, and 2016 was the hottest year on record. Designing a water-wise garden is not only socially and environmentally responsible but will also certainly pay off in lower utility bills.
Proper plant choice, garden design and irrigation use can maximize your garden's beauty while minimizing your effort and expense. If you are interested in making such changes to your garden but need more information, call or e-mail the Master Gardener help desk. The volunteers there can help find answers to any questions you have.
Workshop: U. C. Master Gardeners of Napa County will host a workshop on “Growing Summer Vegetables” on Saturday, March 11, from 9 a.m. to 11 a.m., at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Learn what the garden needs to successfully produce spring and summer vegetables from seeds and seedlings. The workshop will cover soil types and preparation, temperature essentials, watering, fertilizing and harvesting, with a dash of integrated pest management. Online registration (credit card only); Mail-in registration (check only or drop off cash payment).
Garden Forum: Join the U. C. Master Gardeners of Napa County at a forum for home gardeners on Sunday, March 12, from 1 p.m. to 3 p.m., at Yountville Community Center, 6516 Washington Street, Yountville. Bring any questions about anything in the home garden. Questions about fertilizing, watering, planting, plant care, diseases and pests, tools and tool care or nursery purchases are welcome. Register with Yountville Parks & Recreation or contact 707-944-8712.
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.
- Posted by: Yvonne Rasmussen
- Author: Denise Seghesio Levine
October 12, 2012 5:27 pm • DENISE SEGHESIO LEVINE
This is your chance to find plants that are native to the county, and the diversity may surprise you.
This year, the Native Plant Society has more than 1,000 different varieties of plants for sale. Whether you are looking for winter color, drought tolerance, deer resistance or another manzanita for your collection, you will probably find suitable choices at Skyline Park this weekend.
So how to decide? Native Plant Society member Kendra Baumgartner, a plant pathologist with the UC Davis, has grown many natives in her garden and has several favorites.
Bumblebees and hummingbirds are attracted to the bright red blossoms of California fuchsia (Zauschneria californica). This plant produces abundant trumpet-shaped flowers, does well in full sun, spreads easily by roots and is very drought tolerant.
Another colorful, drought-resistant bumblebee favorite that performs well in sun is flannelbush (Fremontodendron californicum). Flannelbush has big, tropical-looking yellow flowers, and it matures into a small tree. At the Martha Walker Native Habitat Garden in Skyline Park, you can see what flannelbush and other native plants look like and how large they grow.
To attract wild and domestic honeybees, consider wild or California lilac (Ceanothus spp.), which flowers in white, purple or blue. For a drought-resistant ground cover in a spot with full sun, choose C. gloriosus porrectus or C. prostratus. Blue beauties like C. ‘Frosty Blue’ and C. ‘Dark Star’ reach six feet tall or more. If you have a large garden, consider C. ‘Ray Hartman,’ which grows up to 18 feet tall.
Looking for color in a shady spot? For red blossoms in full or partial shade, Kendra suggests spice bush (Calycanthus occidentalis). Spice bush needs more water than some natives, since its natural habitat is normally in riparian areas. In addition to its unique, dark red blossoms in spring, spice bush offers the benefit of its spicy fragrance, which the thick, dark green leaves release when brushed or crushed.
Blue-eyed grass (Sisyrinchium bellum) is an herbaceous plant, but it is called a grass because it has blade-shaped leaves that grow in tufts. It spreads by roots, does well in full to partial sun and is drought tolerant. The plant takes its name from its little blue flowers with bright yellow centers, which appear in spring and summer.
Deer grass (Muhlenbergia rigens) is a big bunch grass that grows up to two feet tall. It can be hacked to the ground in winter, and it appreciates regular trimming during the growing season to keep it from looking too wild. In Kendra’s garden, dragonflies perch on the upper leaves, while sparrows take shelter under the canopy of leaves that drape to the ground.
Snowberry (Symphoricarpus albus) is another riparian woodland shrub that matures into a low bush with pretty, delicate leaves and tiny pink flowers. Snowberry produces large white berries in winter, an important food source for birds.
The Native Plant Society has at least nine different manzanita varieties available, from Arctostaphyolos uva-ursi ‘Pt. Reyes,’ a ground cover that stays below two feet in height, to A. ‘Dr. Hurd,’ a manzanita that can grow 10 feet tall. Manzanita is a popular plant in Napa County, for good reason. It has beautiful bark in red, tan and brown and tiny pink or white bell-shaped flowers in spring.
If you have room for a medium to tall tree in full or partial sun, take a look at the blue oaks for sale (Quercus douglasii). Blue oaks have beautiful blue-gray leaves that they drop in winter to reveal draping branches that are a favorite perch for songbirds (and, as Kendra warns, for the Cooper’s hawks that eat them). Blue oaks are drought tolerant once established.
Studies show that fall-planted perennials develop more drought resistance. They get off to a good start in warm soil and then have all winter to develop a deep, strong root system. While most plants need to be watered diligently during their first growing season, fall-planted perennials typically need less water for less time than their spring-planted counterparts.
The California Native Plant Society, Napa Chapter, sale took place Saturday, October 13, 2012 and Sunday, October 14, 2012 from 10 a.m. to 4 p.m. both days. While you are at the sale, pick up some information about the California Native Plant Society. This organization is an excellent resource for information about plants in our area. Consider becoming a member so that you can learn through working with them. Getting to know the plants around us and understanding their natural habitat adds richness to our lives in Napa County.
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