By Daniel McLoughlin, U. C. Master Gardener of Napa County
Most Napa Valley gardeners have long embraced the idea that planting native species is the way to go. These locally evolved species tend to be more acclimated to our long, dry summers and less thirsty as a result.
But there is growing evidence that native plants do far more than just save water. A study by scientists at the University of Delaware and the Smithsonian Migratory Bird Center, recently published in the journal Biological Conservation, underscores another way that native plants can support local ecosystems in urban and suburban settings.
The study was conducted over a four-year span. The observation team identified where breeding birds foraged for food in the yards of 203 homes in the Washington, D.C., metropolitan area. They documented which plants provided the most bird food, such as insects and caterpillars.
Among the findings were that native plants provided more caterpillars than non-native plants, that the birds preferred foraging in native plants and were more likely to breed in sites with native plants.
While these findings may be limited to the specific parameters of this study, the idea that the natural world is deeply interconnected comes as no surprise. We now understand that most insect species evolved over time with a specific plant species or group of plants.The insects adapted to the chemical defenses of its host plants.
Often these adaptations are very precise. Caterpillars, an important food source for birds, tend to be picky about what they eat. For instance, the Monarch butterfly larva must have milkweed (Asclepias fascicularis) to survive. Most insects and animals avoid milkweed because of the toxins and latex it secretes, but the Monarch has adapted to it. In fact, the Monarch will only lay its eggs on milkweed. Without milkweed along its migratory path, the Monarch cannot reproduce and the creatures that feed on Monarch caterpillars must look elsewhere for a meal.
Last year, the Audubon Society launched the Plants for Birds program, which encourages and provides resources for people to support birds by planting native species (http://www.audubon.org/plantsforbirds). The site also provides a database by zip code that helps to identify local native plants and the types of birds they tend to attract (https://www.audubon.org/native-plants).
According to the Audubon Society, the human-dominated landscape “no longer supports functioning ecosystems, and the remaining isolated natural areas are not large enough to support wildlife.” This situation is the result not just of urbanization and expanded agricultural production, but also of our desire for manicured lawns and exotic ornamental plants. Research by the entomologist Doug Tallamy has shown that native oak trees support over 500 species of caterpillars, whereas the gingko, the commonly planted and beautiful landscape tree from Asia, hosts only five species of caterpillars.
ReScape California, also known as the Bay-Friendly Landscaping & Gardening Coalition, is a resource for those who want to learn more about incorporating biodiversity into their landscape. Among its guiding principles are water and energy conservation, improving the “soil food web” and reducing the landscaping impact on landfill.
In this organization's view, maintaining a Bay-friendly landscape means recognizing that “biodiversity is crucial to the health of natural ecosystems and that by using native plants and increasing the diversity of plant palettes, our built landscape can provide food, water and shelter for birds, butterflies, beneficial insects and other creatures.”
According to U.S. Census data, there were nearly 66,000 people living in Napa County in 1960. By 2010 the county's population had more than doubled. That increase mirrored the growth of the Bay Area as a whole, which almost doubled in population in those five decades. Our ancestors needed space to live, just as we do, and so will those who come after us.
I fuss over my lilacs because they demand it and because I love them, but the fact is, they contribute almost nothing to everything else that lives in my yard, or might want to live here. Nothing ever eats them. The same goes for the Australian tea tree, even though it's never thirsty.
I'm not going to pull these plants out, not yet anyway, but the next time I have the chance, I'm going to think about the birds and the bees and the caterpillars. After all, I'm not the only one who lives here.
Workshop: U. C. Master Gardeners of Napa County will host a workshop on “Rose Pruning” on Saturday, January 13, from 10 a.m. to noon, at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Why do we prune roses? Is winter the only time to do it? What will happen if we don't? Should hybrid teas be pruned differently from floribundas? Join the Master Gardener Rose Team at this popular forum where resident experts will answer your questions about basic rose pruning fundamentals with research-based information. Topics include rose types, how and when to prune, what tools to use and how to care for them, safety and sanitation. No doubt each Master Gardener will have some suggestions for new plantings, too. Online registration (credit card only);Mail-in/Walk-in registration(check only or drop off cash payment).
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.
Is the drought over? Not by a long shot. My well is at the same level as it was this time last year, so I will continue to conserve water. How do I do that? By growing drought-tolerant, native, Mediterranean-type plants.
I have been gardening with such plants for many years. Last summer was a test of how well they would do with no summer watering. I did not water at all over the summer and lost only one plant.
I have nine swales in my garden. A swale is a shallow trench used to harvest rainwater and slowly release it into the soil. Plants tap into this reserve when water is scarce. Swales conform to the contour of the soil and have berms alongside that can be used for planting.
Several natives that have done well in my garden are sticky monkey flower (Mimulus aurantiacus), lavenders of many types, bottlebrush (Callistemon), native iris, red-hot poker (Kniphofia ), butterfly bush (Buddleja), milkweed (Asclepias) and salvias. I have intentionally created a habitat garden with lots of room and bloom for birds, butterflies and bugs. Right now, my breadseed poppies are showing their beautiful red heads. I started these with just a few seeds, and they have re-seeded widely.
Some monkey flowers have sticky leaves; others do not. These plants are native to Oregon, California and Baja California. The flowers look like little monkey faces and come in a variety of colors. Many hybrids have been developed and the flower colors are outstanding. They bloom over a long period, survived all summer in my garden without water and are up and blooming now. The plants can reach three to four feet in height and can be trimmed back.
Lavender thrives in my garden. Last year some went to seed, and wind and birds spread the seed. Now lavender in many colors is sprouting in other areas. There is even a white one, and I guess I can thank the bees for that. I have never had white lavender before.
Bottlebrush is native to Austrialia. It can take the form of a large bush or tree depending on how it is pruned. I have a couple that I keep as low bushes.
The flower of the Pacific Coast iris (Iris douglasiana) is typically blue, but hybrids have many different flower colors. I have a beautiful white one. My Iris confusa ‘Chengdu' came from a Bay Area grower; it grows well in shade without any summer water. It is one of my favorites.
Salvias are native to many parts of the world. Every time I think I have all my favorites, new ones appear. One identifying feature of sage is its square stem. Some salvias tower over me (I am petite), while others stay low. There are more than 900 species worldwide, so I don't plan on collecting all of them. I only have one acre. Sage blossoms are spectacular, and the leaves are aromatic. I love to rub my hands over the leaves and then smell the fragrance.
I have many milkweeds in my garden. They are mostly drought tolerant, and bees and bugs love them. Milkweed is the only food source for the larvae of the Monarch butterfly, and I want to encourage as many of them as I can. The Monarchs in the western U.S. evolved with native milkweed; they lay their eggs on milkweed. Most milkweeds die back in winter and come up in spring with big, bright flowers. Their milky sap make the larvae taste bad to birds, so they leave the larvae alone.
When I visited Turkey, I saw breadseed poppies (Papaver orientale) everywhere, their red heads waving in the breeze. I also saw them in some of the countries on the Dalmatian coast. The seeds from these poppies are sprinkled on baked goods.
My two large habitat garden areas are filled with native plants and take less time and water then the lawn they replaced. Gardening with natives is a great strategy for creating a water-wise yet beautiful landscape.
Workshop: Napa County Master Gardeners will hold a workshop on “Oaks and Native Plants” on Saturday, May 7, from 9:30 a.m. to 11:30 a.m., at Skyline Park, 2201 Imola Avenue, Napa. Stroll Skyline Park and the Martha Walker Garden to view oaks in their native habitat. Discover what grows alongside and underneath oaks. Learn about planting under oak trees in your own garden, about caring for oaks and about Sudden Oak Death and other stresses. On-line registration (credit card only) Mail-in/Walk-in registration (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.
When the Napa County Master Gardeners decided to field-test kale last year, I decided it was finally time try some. Kale comes in many shapes, sizes, colors and textures, and catalogs offer a huge selection of seed.
When you growing plants from seed, you have a wider selection than what the nurseries or “big-box” stores typically carry. What's more, some of the vegetable varieties that the nursery trade grows are chosen for their ability to withstand handling, transport and display, not necessarily for their taste.
Kale is a fast-growing source of greens during our cool season. Most kales are extremely winter hardy and become sweeter with frost. Harvest can continue through winter in Napa County. Kale can be eaten raw in salads or cooked for a side dish, pasta or soup. Many of the colored varieties, including some that we grew in our trial, make attractive ornamental plants.
Harvest leaves from the outside so that the plant can continue to push new leaves from the center. As the plants mature and you remove more outside leaves, the plants can start to look like miniature trees with foliage on top of a long stem.
The field-test committee grew three varieties of kale last fall, all strikingly different.We evaluated each type for productivity, vigor and health, and for flavor and texture, both cooked and uncooked. All three types had high germination rates, ranging from 87 percent to 91 percent.
One variety we grew was 'Nero di Toscana,' a popular type often seen in grocery stores. This Italian heirloom has strap-like leaves about 3 inches and 10 to 18 inches long. It is familiarly known as dinosaur kale because of its crinkly texture.
We also tested 'Red Ursa' kale, a Russian variety. It grows into a gorgeous plant with a fountain of big frilly leaves with purple veins and stems. 'Dwarf Blue Curled Scotch' was our third selection. It is a low-growing, spreading, early kale with tightly curled, blue-green leaves, beautiful enough to be grown solely as an ornamental. The other two varieties rated higher in most categories, but no single variety was the unanimous favorite.
Some field testers found 'Blue Curled Scotch' harder to clean because of its curly leaves, and chewier and stronger in flavor. Others thought 'Red Ursa' was the prettiest and easy to use in cooking and salads. 'Nero di Toscana' generated the most enthusiastic comments and was voted most likely to be planted again. Master Gardeners liked its flavor and found it more tender and productive than the others, although it suffered more damage from cabbage larvae. Row covers helped keep bird damage to a minimum. Other pests that can damage kale include slugs and snails, cutworms, flea beetles, cabbage-root maggots and aphids.
A majority of testers said that they would grow kale again. There was a lot of enthusiasm and recipe-swapping at our meetings, with kale featured in everything from soup to chips to smoothies. Many especially enjoyed kale raw in salads. Testers appreciated that the plants produced for a long time if they harvested only outside leaves.
You can plant kale seed directly in the ground from the third week of July until mid-August. Protect young seedlings from insect damage by using row cover. You can also start kale indoors and set out transplants from the third week of August through mid-September.
Kale likes full sun but can benefit from light shade during hot weather. It prefers consistent moisture but can tolerate drought, although the flavor will suffer. Cool weather slows the damage from pests, making kale easier to grow. To minimize disease, avoid planting kale or other cabbage-family crops in the same location more than once every three to four years. Seed remains viable for up to four years.
Garden Tour: The Master Gardeners of Napa County invite you to attend their sixth garden tour, “Down the Garden Path,” on Sunday, September 13. On this self-guided educational tour, you will see seven gardens owned by Master Gardeners in and around the City of Napa. These gardens illustrate how Napa County Master Gardeners use University of California research-based horticultural information to develop and maintain their own gardens. Tickets: $30 advance / $35 day of event. Purchase tickets here - http://bit.ly/1fqLJZe. Or you can purchase tickets at the Master Gardener office (address below). For more information, call 707-253-4143.
Workshop: Napa County Master Gardeners will hold a workshop on “Home Vineyard: Part 2” on Saturday, August 15, from 9:30 a.m. to 2 p.m. (with a 30-minute lunch break. Learn what to do and what to look for and how to plan for harvest and crush in the vineyard, testing the must, managing the vines after crush, and preparing for winter and the next growing season. Master Gardeners with home vineyards will present this workshop, and answer your questions. Please bring a sack lunch, comfortable clothes and shoes for walking through the experimental vineyard. Location is the University of California Oakville Experimental Station, 1380 Oakville Grade Road, Napa. Online registration (credit card only)Mail-in registration (cash or check only)
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. Napa County Master Gardeners ( http://ucanr.org/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.
A few years ago, we heard from Toby Hemenway who wrote Gaia's Garden: A Guide to Home-Scale Permaculture. I studied this book and was very interested in the part he wrote about swales in the garden.
I wanted a habitat garden with native plants in one area of my property. A habitat garden gives small animals places to hide, provides nectar plants for insects and is low maintenance.
I decided that swales were going to be part of this garden since the rainwater needs somewhere to drain. Some swales are filled with twigs and covered with soil, but I wanted my swales to be open so they could be cleaned and so that I could observe what the water was doing. One of my neighbors refers to my swales as “Penny's lakes.”
The ground around the swales has to be saturated from rain before they start to hold water. The water should not remain in the swale more than three days; over that time, it should slowly be absorbed into the soil. The swale creates a damp area where plants can get water during dry periods. My friends are used to me saying,“The swales are full!”
About three years ago, the soil from the swales was mounded and planted with California natives and other low-water-use mediterranean plants. For the first couple of years, I watered them as needed, but last year this area received no water during the entire summer. I may decide to plant some native milkweeds there this fall; if so, I will need to water them next summer.
Mulching is one way to keep plants alive during dry spells. You can mulch with your own compost (if you're not already composting, you can learn to do it in a Master Gardener composting workshop). Or you can buy compost from companies that grind bark and wood into mulch.
After watering the ground well, spread three to four inches of mulch over the soil. You will be amazed how well it keeps water in the soil and available for plants.
Some of the plants I like to use are lavender, lamb's ears, salvias, monkey flower (mimulus), lily-of-the-Nile and yarrow. Some monkey flowers are sticky; others are not. Both types have beautiful flowers in a variety of colors and bloom almost continuously. With a little deadheading they grow right back.
My lavenders have a long bloom period, and bees enjoy them from morning until dusk. Whatever plants you choose, plant them in multiples to make a bigger splash of color and texture.
Local “Cash for Grass” programs are ongoing. You must apply to the City of Napa or American Canyon, and officials will come inspect your grass. Be sure to keep it alive until then. If approved, you will receive a grant to replace your grass. Then you can proceed with plans to create a habitat garden, dry garden, succulent garden or other garden of your choosing.
Walk your neighborhood to see what others have done. Peruse books for design ideas and visit local nurseries for plant suggestions.Gather information before you start.
You don't have to tear out your lawn. You can cover it with large pieces of clean cardboard, and then cover the cardboard with lots of mulch. Worms and other micro organisms will eat the cardboard and decompose it for you. In a few months you will have a dead lawn and some good soil to plant in.
If you're resourceful, drought does not mean the end of your landscape; it just means a different way of doing things.
Workshop: Napa County Master Gardeners will lead a workshop on “Drought-Tolerant and California Native Plants” on Saturday, August 1, from 9:30 a.m. to 11:30 a.m., at Martha Walker Garden in Skyline Park in Napa. Enjoy a walk around the garden to observe drought-tolerant and native plants, and discover the elements that help them thrive in our Mediterranean climate. Learn how to use them in your own garden to replace some of those water-hungry ornamentals.On-line registration (credit card only) Mail-in registration (cash or check only)
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. Napa County Master Gardeners ( http://ucanr.org/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.
For now, I've turned my energies to creating a rain garden in an area of my yard that tends to produce runoff. In wet weather, this silty water flows onto the sidewalk and then into the street. The plans that I perused required creating a declivity or basin filled with and surrounded by foliage and larger rocks.
The rain garden is not a pond feature; it is actually dry most of the time. It is intended to hold water only briefly during and after a rain, allowing water to filter slowly through the soil and rocks.
People have collected rainwater since ancient times, but the modern rain-garden concept originated in Prince George's County, Maryland, in 1990. By keeping water off the sidewalks and out of the streets,a rain-retention basin reduces the flow of contaminated water into storm drains. It slows the water flow, allowing soil and plants to break down and filter out the pollutants.
Select your location carefully. Look for a natural declivity or a flat place that receives water from a downspout or overland flow during a storm. You can construct a rain garden on a hill but that requires more digging. Avoid locating it over a septic system or near tree roots. Also consider how the nearby landscape plants might adapt to the new watering regime. Finally, avoid underground pipes and pick an area that gets full or partial sun.
Choose a design that complements your existing landscape. Size depends on the collection surface; a 1,000-square-foot rooftop requires at least a 200-square-foot garden. The garden should be able to hold an inch of rain at one time.
In our mediterranean-type climate, we can expect little or no rainfall for at least six months every year. With that in mind, choose native or drought-tolerant plants. Those plants in the basin and the ones on the berm will have different water access so plan accordingly.
You will have to water your plantings for the first year or so, until they get established. Mulch them with a heavy material,such as shredded wood or wood chips, that won't float away during the flooded periods.
The area under consideration in my yard was actually a raised mound. After a rain there was always a mud slick on the sidewalk that filled up the parking strip and then flowed into the street.
The hiccup in my plans was when I realized that I would have to remove and dispose of an astronomical amount of soil. So I had to shelve the rain-garden concept. I solved the runoff problem by digging a two- by two-foot trench around the mound. As it was, I was hard put to find a home for just that amount of soil.
All my garden beds needed freshening, so I mixed the excavated soil with equal amounts of compost and topsoil. With that mixture, I fluffed up my planting beds. I then filled the resulting trench with about six inches of gravel and topped it off with two- by three-inch cobbles that matched the rest of my landscape. I now have created a so-called French drain around the problem location.
Although I am not using the water for irrigation, I hope that percolating the water through the rocks will cleanse it naturally. Based on the meager rains we've had since I completed the work, the water is definitely being re-routed. I no longer see a mud slick on the sidewalk. Instead, the trenches catch the runoff to refill the aquifer.
I was really looking forward to creating a rain garden, but you do the best you can with the situation you have. I planted a succulent garden on the remaining mound, which will help conserve water, and I am quite happy with the result
For more information on creating a rain garden, visit the website of the Watershed Information Center & Conservancy. Also check out the website of California Sea Grant (https://caseagrant.ucsd.edu/sites/default/files/GS3%20Rain%20Gardens_8-10-09.pdf.)
Workshop: Napa County Master Gardeners will lead a workshop on “Drought-Tolerant and California Native Plants” on Saturday, August 1, from 9:30 a.m. to 11:30 a.m., at Martha Walker Garden in Skyline Park in Napa. Enjoy a walk around the garden to observe drought-tolerant and native plants, and discover the elements that help them thrive in our mediterranean climate. Learn how to use them in your own garden to replace some of those water-hungry ornamentals. On-line registration (credit card only) Mail-in registration (cash or check only)
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. Napa County Master Gardeners ( http://ucanr.org/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.
