- Author: David Layland, U. C. Master Gardener of Napa County
Grapevines in Napa Valley are breaking their dormancy after enjoying their winter nap. If you haven't done so already, get out your pruning shears, sharpen them, and make sure they are functioning properly. Grapevines need a haircut now to be at their best in 2024.
Having a successful year in your home vineyard depends on paying attention to several factors.
Understanding climate shifts is vital to maintaining any garden, especially vineyards given how long grapevines can live. If you have a vineyard or are planning one, your understanding of the impact of climate change will affect your success, and not only from the perspective of irrigation. Making the best decisions for your home vineyard requires staying abreast of current research.
We know that soil influences the quality of wine grapes. Soil is a non-renewable resource essential for climate regulation and sustainable grape production. We build soil health with practices that promote the accumulation of organic matter and biodiversity. These practices make for a more resilient, productive, and long-lived vineyard.
Napa Valley soils are diverse with distinctive characteristics. The valley is home to deep, rich alluvial soils, rocky hillsides, and volcanic soils found in a wide range of topographies. This soil diversity is one reason that the valley's vineyards include more than forty wine-grape varieties.
You can increase organic matter in your soil by planting cover crops. They improve soil structure, mineral fertility, and biological activity. Compost provides nutrients for plant growth, increases soil organic matter and mitigates erosion.
Irrigating your vineyard on a proper schedule will help you save on electricity, water, and labor. Dry farming—growing grapes with little or no irrigation—is possible for some vineyards but not all.
The annual growth cycle of grapevines begins with bud break in the spring and culminates in autumn with harvest and leaf drop, followed by winter dormancy.
Climate change has affected the duration of each phase of the growth cycle, making it important to understand these changes so you can adapt. Sustainable practices help adapt to climate change.
Powdery mildew, one of the most widespread and easily recognized plant diseases, is the number one pest in the vineyard and one that if managed successfully will give better fruit quality. It is characterized by spots or patches of white to grayish, talcum-powder-like growth. Powdery mildews are severe in warm, dry climates such as ours. Treatment is usually with elemental sulfur and begins at bud break. For a deeper dive into home vineyard management, plan to attend the Napa County Master Gardener workshop on Saturday, March 30. See details below.
Workshop: Join UC Master Gardeners of Napa County for “Home Vineyards: Important Information for a Successful 2024,” on Saturday, March 30, from 9 am to 12:30 pm. Learn the latest about irrigation and treating viruses and mildew. Get up to date on climate change, soil health and structure, increasing soil organic matter and what happens in the vineyard post pruning. The workshop will be held in a barn at a private home vineyard near Napa. Attendance is free but you must register to get the address and additional details. https://surveys.ucanr.edu/survey.cfm?surveynumber=42128
Library Talk: Join UC Master Gardeners and Napa County Library for a talk on “Growing Tomatoes in Small Spaces” on Thursday, April 4, from 7 pm to 8 pm, via Zoom.Learn how to grow fabulous tomatoes in containers— on patios, on decks, and in other small Register to receive the Zoom link:https://surveys.ucanr.edu/survey.cfm?surveynumber=41782
Help Desk: The Master Gardener Help Desk is available to answer your garden questions on Mondays and Fridays from 10 a.m. until 1 p.m. at the University of California Cooperative Extension Office, 1710 Soscol Avenue, Suite 4, Napa. Or send your questions to mastergardeners@countyofnapa.org. Include your name, address, phone number, and a brief description.
- Author: Cindy Watter, UC Master Gardener of Napa County
The UC Master Gardener's February meeting was enlivened by Gordon A. Walker, Ph.D., otherwise known as the “fungus guy.” Walker has a doctorate in biochemistry and molecular biology from U.C. Davis and worked in the wine industry for a time. I have noticed that many people who are interested in mushrooms have a background in winemaking or bread baking. I think it's related to the fermentation.
Walker's avocation, however, is learning all about wild mushrooms, preferably in their natural habitat, and teaching people about them. He lives in Napa and tries to take a walk in the woods every day.
Walker finds fungi endlessly enthralling, and if you follow him on social media, you will, too. His website is called “Fascinated By Fungi,” and he has a podcast and YouTube channel by that name as well. I spent several hours exploring them, and I learned a lot. You can also sign up for one of his guided mushroom walks or keep an eye out for his mushroom-themed dinners at local restaurants.
My attraction to wild mushrooms is, first, their beauty, and second, their edibility. I have friends in Santa Cruz who are mushroom foragers, and it seems that every year during mushroom season some hapless daredevil ends up with liver damage from a misidentified tidbit that turned out to be poisonous. The way to avoid this fate is to learn how to recognize the evil-doers.
Walker, in his lecture to the Master Gardeners, recommended Mushrooms of the Redwood Coast, by Noah Siegel and Christian Schwarz. The book is packed with color pictures, information about habitat and—very important—guidance on edibility.
For example, the honey mushroom (Armillaria mellea) found in Napa County growing on oaks and madrone is quite tasty, but you should only eat the caps of young specimens. The stipes (stems) are tough. The caps should be thoroughly cooked to avoid an upset stomach.
From one of Walker's podcasts, I learned about the iNaturalist app, sponsored by the California Academy of Science. The app is free and, once installed on your phone, it allows you to connect with amateur and professional naturalists who can help you identify wild mushrooms you find. Send in your photographs and you will get replies.
Walker offered tips for photographing mushrooms for identification purposes. Get down and photograph the fungi at their level, including the stems and gills. Don't forget to take shots of the habitat where you found them; that's helpful for identification.
Walker told the Master Gardeners about the “top-tier wild mushrooms:” chanterelle (Cantharellus), king boletus/porcini (Boletus edulis), hedgehog (Hydnum repandum), black trumpet (Craterellus), lion's mane (Hericium erinaceus), chicken of the woods (Laetiporous sulphureus), cauliflower (Sparissus) and black and blonde morel (Morchello).
He also showed us images of poisonous mushrooms. To me, jack o'lantern (Omphalotus olearius) looked uncomfortably similar to chicken of the woods, and death cap (A. phalloides) to hedgehog. This is why one should pay attention to variations in the rim of the cap, the gills, and the habitat.
On the other hand, the familiar fly agaric (Amanita muscaria) was its readily recognizable self: red with white dots, just like the ones in the old fairy-tale illustrations. This colorful fungus is quite cosmopolitan; it is found all over the world. I have seen it under oak and eucalyptus trees in Napa. Siegel and Schwarz describe it as “extremely toxic and mind altering.”
It isn't hard to grow wild mushrooms at home. The Sierra Club recommends oyster mushrooms (Pleurotus ostreatus) as the easiest to grow. Oyster mushrooms are considered saprophytic fungi as they grow on decaying oak and alder. The word “saprophytic” comes from the Greek sapros (which means putrid) and phyton (which means plant). It is an attractive mushroom that grows in layers, shaped like an oyster shell or fan.
To grow mushrooms at home, you need to buy a mushroom block—mushroom spawn pressed into a block with substrate (growing medium). Keep it out of direct light and in a humid environment, such as near a kitchen sink or in a plastic bag with holes in it and wait.
Mushroom spawn is a mix of mycelium, an active mushroom culture that looks like white threads. Oyster mushrooms are fast growing, and you can often start harvesting after a week. You can generally get two crops from a single mushroom block, and sometimes as many as five. In the springtime you can take the block outside.
You can also create a mushroom patch in your yard, roughing up the dirt under a tree or under tall vegetables, adding clean hardwood chips, and then adding spawn. Keep the area damp.
Or you can buy mushroom spawn, put it in a clean plastic 5-gallon bucket with holes in it and layer in more substrate. (Wood chips and cut-up cardboard work well.) Keep it damp with a spray bottle, and you will have mushrooms.
My compost pile is loaded with mycelium. If I stopped turning it, I would have mushrooms.
The Sierra Club suggests purchasing your mushroom-growing supplies locally. Some unscrupulous mushroom dealers are irresponsible about contamination or may sell you spawn for supermarket mushrooms. Check with local nurseries. The Napa Farmers Market also has a mushroom purveyor, Far West Fungi, who sells mushroom growing supplies.
We still have so much to learn about the world of fungi. A walk in the woods is a good place to start.
Workshop: Join UC Master Gardeners of Napa County for “Spring into Summer Vegetable Garden” on Saturday, March 17, from 2 pm to 4 pm, at Yountville Community Center, 6516 Washington Street, Yountville. Plan your vegetable growing for the warm weather ahead. Topics include soil prep, fertilizing, managing pests, irrigation, and planting schedules. This is a hands-on workshop and registration is required. To register, contact the Yountville Parks and Recreation Department.
Workshop: Join UC Master Gardeners of Napa County for “Home Vineyards: Important Information for a Successful 2024,” on Saturday, March 30, from 9 am to 12:30 pm.
Learn the latest about irrigation and treating viruses and mildew. Get up to date on climate change, soil health and structure, increasing soil organic matter and what happens in the vineyard post pruning. Workshop will be held in a barn at a private home vineyard near Napa. Attendance is free but you must register to get the address and additional details. https://surveys.ucanr.edu/survey.cfm?surveynumber=42128
Help Desk: The Master Gardener Help Desk is available to answer your garden questions on Mondays and Fridays from 10 a.m. until 1 p.m. at the University of California Cooperative Extension Office, 1710 Soscol Avenue, Suite 4, Napa. Or send your questions to mastergardeners@countyofnapa.org. Include your name, address, phone number and a brief description.
- Author: Starr Green, UC Master Gardener of Napa County
On a jog up Napa's Dry Creek Road recently, I saw a magnificent sight: thousands of ladybugs clumped together on fences (even barbed wire) and on old, mossy tree stumps. The most unusual ladybug sighting was on a roadside reflector marker.
Being a first-year Master Gardener, I was determined to find out why they were all huddled together and what kind of ladybug loves to mass like this.
After much research, I learned that the ladybug I found is the convergent lady beetle (Hippodamia convergens). It is the most common lady beetle species in Napa County.
The pictures I took show a rounded, somewhat oval creature, bright orange with at least 12 black spots. This description matches the anatomy of the convergent lady beetle, aka ladybug.
Most convergent lady beetles are less than an inch long and oval, with six short legs. They are usually brightly colored with some sort of pattern, such as spots. These colors and patterns warn predators that the lady beetle not only tastes bad; she's poisonous.
These beetles have eight body parts: antennae, eyes, three body segments (head, thorax, and abdomen), legs and two pairs of wings. The area behind the head is black with a white border and two white converging lines, which is why it's called a convergent lady beetle. Adult lady beetles are easily distinguished by their bright red/orange hardened forewings with six black spots on each. The legs, head and underside are all black.
Lady beetle legs are short with segmented feet that can cling to slippery surfaces by secreting a fluid. This capability enables lady beetles to walk on glassy, smooth surfaces without slipping. That's how they were able to stay on the slippery reflector marker.
Researchers are developing new adhesive technologies modeled on this feature. .
The first cold weather signals to lady beetles that it's time to search for a warmer place to spend the winter. They are cold-blooded insects that need external heat to keep their bodies at the right temperature. During hibernation, they'll often gather in groups for warmth.
The forest on Dry Creek Road that these lady beetles picked was a perfect spot to overwinter. I found them hiding in tree bark and nooks of oak trees.
In our area, they start hibernating around mid-October. Their metabolism slows and they enter a state of sleep. During this time, they sustain themselves with the fat reserves they stored in summer.
What happens next in the lady beetle's life cycle? Once they leave the moist forest in spring, they will need to track down food to rebuild their stamina. They adjust their life cycle according to the availability of aphids.
Lady beetles develop through four life stages: egg, larva, pupa, and adult. Amazingly, the females may lay as many as 1,000 eggs over a one- to three-month period beginning in the spring or early summer. Eggs are usually deposited near prey, such as aphids, in small clusters in protected places like leaves and stems.
The eggs are tiny, about 1 millimeter, and spindle shaped. The larvae are dark, and alligator shaped with three pairs of prominent legs. That would definitely give me a scare.
These larvae feed voraciously. In two weeks, one larva can eat 350 to 400 aphids. They also eat other soft-bodied insects, such as mites and insect eggs (even their own).
The newly hatched larva is in its first instar, a developmental stage that occurs between molts. The larva feeds until it is too big for its soft shell, then it molts.
Ladybug larvae usually molt through four instars, or larval stages, before preparing to pupate. Here the larva attaches itself to a leaf or other surface as it prepares to metamorphose into adult form. The newly formed adults are vulnerable to predators until their shells, or cuticles, harden. They will soon develop the beautiful colors I saw on my jog.
You can keep aphid populations down by controlling ants and washing dust off plants. Ants protect aphids, so controlling ants keeps ladybugs free to take care of the aphids.
I've seen containers of lady beetles for sale in stores to help control the aphids we get on our roses and other plants in our gardens. If you purchase lady beetles for aphid control, wet your plants first and release the beetles in late evening when it's cooler. Those steps may keep the lady beetles in your garden longer. Growing flowering plants, which provide pollen and nectar, will also help keep ladybugs from moving on.
To protect lady beetles, please avoid using broad-spectrum persistent insecticides. The UC IPM website has a lot more information on lady beetles.
I went back to the site of the beetles on Dry Creek Road after a big storm and most were gone. Hopefully, they found a better place to hide and stay dry.
Workshop: Join UC Master Gardeners of Napa County for “Spring into Summer Vegetable Garden” on Saturday, March 17, from 2 pm to 4 pm, at Yountville Community Center, 6516 Washington Street, Yountville. Plan your vegetable growing for the warm weather ahead. Topics include soil prep, fertilizing, managing pests, irrigation, and planting schedules. This is a hands-on workshop and registration is required. To register, contact the Yountville Parks and Recreation Department.
Workshop: Join UC Master Gardeners of Napa County for “Home Vineyards: Important Information for a Successful 2024,” on Saturday, March 30, from 9 am to 12:30 pm.
Learn the latest about irrigation and treating viruses and mildew. Get up to date on climate change, soil health and structure, increasing soil organic matter and what happens in the vineyard post pruning. Workshop will be held in a barn at a private home vineyard near Napa. Attendance is free but you must register to get the address and additional details. https://surveys.ucanr.edu/survey.cfm?surveynumber=42128Help Desk: The Master Gardener Help Desk is available to answer your garden questions on Mondays and Fridays from 10 a.m. until 1 p.m. at the University of California Cooperative Extension Office, 1710 Soscol Avenue, Suite 4, Napa. Or send your questions to mastergardeners@countyofnapa.org. Include your name, address, phone number and a brief description.
*With apologies to the Isley Brothers
- Author: Pat Hitchcock, UC Master Gardener of Napa County
Have you heard the term “shoulder season”? Sometimes it refers to in-between times at resorts when neither winter sports nor summer activities are available. Recently I've been thinking that it also applies to late winter and early spring in our vegetable gardens.
Many home garden plots will soon be full to bursting with warmth-loving crops like tomatoes, squash, and beans, but until then the garden space is empty and unproductive.
With a little effort, you can plant many cool-season vegetables now and harvest them in time to plant the summer veggies, too.
Vegetable crops grow at different rates. Seed packets, seed catalogs and nursery tags usually list the “days to maturity” for a given crop. It is worth noting that the days to maturity are based upon ideal growing conditions; actual harvest dates will vary. Also, some maturity dates refer to the number of days after transplanting, not from the date of seeding. But when you are considering whether you have enough time to grow a crop to maturity, they are a useful guide.
A good time to plant tomatoes in the ground is mid-April, not coincidentally when the Master Gardeners have their Tomato Festival and sale. The space where you intend to put tomatoes is thus available for the next six weeks or so. Why not plant some arugula, lettuce, or radishes there? All these vegetables may be planted from seed now.
Small red radishes are usually ready to eat about a month after sowing. Arugula and leaf lettuces are fast growers, and you can start harvesting as soon as the plants have some leaves. Create your own baby salad mix with these and other greens such as kale, mustards, and chard that you can harvest young.
If your greens are still producing when it is time to set out tomato seedlings, just remove enough of the greens to make room for the relatively small tomato plants. You can continue to harvest the rest of the greens until the tomatoes overwhelm them.
By mid-May, your soil will be warm enough to plant all kinds of beans, squash, cucumbers, and peppers. To take advantage of the weeks until then, how about growing something in that space that needs a little more time to mature? Asian vegetables such as baby bok choy, tat soi and gai lan (aka Chinese broccoli) take 55 to 60 days to reach maturity according to their seed packets. Likewise, baby beets and baby turnips need roughly the same amount of time.
Because our summer growing season is long, approximately mid-April to mid-November (based upon first and last frost dates), you can delay planting some heat-loving vegetables like beans, cucumbers, and summer squash until June or even later to allow more time for growing cool-season vegetables.
Peas and carrots planted from seed now will produce by May or June. You can also expect transplants of broccoli, cauliflower, and cabbages to be finished by June, leaving space for the warm-season crops. Nurseries and garden centers should have a good variety of these brassica vegetables for sale now if you did not start your own plants six weeks ago.
If you take advantage of this time of year for planting cool-season crops, you may eventually find yourself growing vegetables year-round. The secret to success is knowing which crops thrive in the cooler parts of the year and how much time they need to mature.
Library Talk: UC Master Gardeners of Napa County and Napa Library will host a talk on Thursday, March 7, on “Agaves - More Than Tequila and Century Plants” from 7 pm to 8 pm via Zoom. Learn more about adding these deer-proof, beautiful and low-maintenance plants to your garden. Register Here to receive the free Zoom link.
Workshop: Join UC Master Gardeners of Napa County for “Spring into Summer Vegetable Garden” on Saturday, March 9, from 10 am to noon, at the University of California Cooperative Extension office, 1710 Soscol Avenue, Napa. Plan your vegetable growing for the warm weather ahead. Topics include soil prep, fertilizing, managing pests, irrigation, and planting schedules. This is a hands-on workshop and registration is required. This workshop repeats on Saturday, March 17, from 2 pm to 4pm, at Yountville Community Center, 6516 Washington Street, Yountville. To register, contact the Yountville Parks and Recreation Department.
Help Desk: The Master Gardener Help Desk is available to answer your garden questions on Mondays and Fridays from 10 a.m. until 1 p.m. at the University of California Cooperative Extension Office, 1710 Soscol Avenue, Suite 4, Napa. Or send your questions to mastergardeners@countyofnapa.org. Include your name, address, phone number and a brief description.
- Author: Cindy Watter, UC Master Gardener of Napa County
I enjoy wandering Napa's neighborhoods, admiring the front yards, and noting the changes in landscape gardening styles. There has been quite a metamorphosis over the decades. Many people have moved from lush English-style landscaping to water-wise gardening.
Not so long ago, during one of our droughts, it seemed as if every other person traded in a lawn for a layer of river rocks. This was an overly austere alteration, and I am happy to see that rocks and decomposed granite are being augmented with plants that are attractive and don't need much water. One such plant is agave.
Agave (Asparagaceae) is a succulent, related to asparagus and native to Mexico. There are over 250 varieties of agave cultivated today. Agave is often confused with aloe, and is sometimes called “American aloe,” but it is not the same. Agaves grow in a rosette pattern, often with spear- like leaves, and range from 18 inches to eight feet wide.
I think they look suitable in almost any garden setting, with any sort of architecture, but they are especially harmonious with mid-century modern or high-tech settings. Some varieties, particularly the ones with embossed-looking leaves, look good with older houses.
Agaves are easy to grow. Because they are desert plants, they need very little water; in fact, overwatering is the source of most agaves' problems. If they are truly parched, they will shrivel a bit, but will quickly plump up when irrigated.
You should wait until the soil around an agave is bone dry before you give it water. Avoid pouring water into the agave rosette and water it from the side.
The agave weevil is the plant's main pest, and it is easy to spot. The weevils are about an inch long and black, and they chew holes in the fleshy part of the agave leaf. Then they lay eggs in the holes.
Weevils are more likely to attack a weakened agave, so don't overwater. If they do appear, it is best to dispose of the plant and start over. That said, I have never seen an agave weevil on any of the plants I have been observing.
Propagating agave couldn't be easier. An agave in my neighborhood has outgrown its original pot, cracking the bottom and revealing rhizomes, or “pups.” These rhizomes can be removed and planted.
Spring is the best time for planting. Choose a planting medium or a site that drains well. Sandy soil or a planting mix formulated for cactus is ideal.
When you consider where to plant agave, remember that it will need at least six hours of sun a day. Also, some types have toothed or spiked leaf edges, so you may want to keep these types away from paths.
You can trim those edges, taking care not to cut into the flesh of the leaves. Or you can plant them where no one will wander. Alternatively, you can grow smooth-edge agave and avoid the problem. Pets or children should not ingest agave, but given the spikes, that's unlikely to happen.
Avoid fertilizing agave. Fertilizer promotes flowering, and an agave dies off after flowering, although you can still collect the seeds and plant them.
A. americana, the so-called century plant, got its nickname because people thought it flowered once in a hundred years. It actually puts forth a very tall bloom after ten years. This agave variety makes a dramatic statement in a garden, reaching eight feet in height. It is a beautiful blue green, with hooked spines along the edge of its leaves and a sharp spike at the tip of each leaf. Sunset's Western Garden Book says, “Make sure you really want one before you plant it” as it would be hard to move.
The Sunset book lists agaves by size, color, and “spikiness” so you can decide which to plant—or just ask at your local nursery. So many agaves grow well in Napa Valley that one could have a garden filled with nothing else and still have variety in the landscape.
Some people grow agaves in containers. If they have a particularly cold microclimate, they move the containers indoors for the season or wrap them in a thermal blanket at night.
Growing agave for tequila- and mezcal-inspired beverages is a burgeoning business now. As California's climate continues to become hotter and drier, agave cultivation in the state should only increase. Agave is also a good firebreak plant, protecting more flammable crops.
Craig Reynolds, president of the California Agave Council, a trade organization of 70 growers and a dozen craft distillers, told me he likes to grow agave at home in large ceramic pots. He has the same advice for the home gardener as he has for farmworkers: Wear long, gauntlet-style gloves when you work with agave. The sap contains calcium oxalate, an irritant that can induce a long-lasting skin rash. Of course, wearing gloves in the garden is a good practice anyway.
If you want to learn more about agave, the UC Master Gardeners of Napa County are hosting a Library Talk in conjunction with the Napa City-County Library on Thursday, March 7, from 7 pm to 8 pm via Zoom. See registration details below.
Library Talk: UC Master Gardeners of Napa County and Napa Library will host a talk on Thursday, March 7, on “Agaves - More Than Tequila and Century Plants” from 7 pm to 8 pm via Zoom. Learn more about adding these deer-proof, beautiful and low-maintenance plants to your garden. Register Here to receive the free Zoom link.
Workshop: Join UC Master Gardeners of Napa County for “Spring Into Summer Vegetable Garden” on Saturday, March 9, from 10 am to noon, at the University of California Cooperative Extension office, 1710 Soscol Avenue, Napa. Plan your vegetable growing for the warm weather ahead. Topics include soil prep, fertilizing, managing pests, irrigation, and planting schedules. This is a hands-on workshop and registration is required.
This workshop repeats on Saturday, March 17, from 2 pm to 4pm, at Yountville Community Center, 6516 Washington Street, Yountville. To register, contact the Yountville Parks and Recreation Department.
Help Desk: The Master Gardener Help Desk is available to answer your garden questions on Mondays and Fridays from 10 a.m. until 1 p.m. at the University of California Cooperative Extension Office, 1710 Soscol Avenue, Suite 4, Napa. Or send your questions to mastergardeners@countyofnapa.org. Include your name, address, phone number and a brief description.