For me, the Napa County Master Gardener tomato sale elicits heavenly thoughts of tastes to come. I adore tomatoes. My husband once planted 18 plants for the two of us. I used every tomato—either by eating, cooking, dehydrating or freezing them. We have home-grown tomatoes year-round.
At the end of the season, I put the remaining vines of green tomatoes in a paper bag in a cool, dark space. They continue to ripen. We have eaten fresh tomatoes this way into January.
Thank you to all who attended the Master Gardener tomato sale on Earth Day. There were many competing events that day, so we appreciate that you took the time to find our new location and purchase our seedlings.
After the sale, we moved the unsold plants back to our greenhouse. By the following Tuesday, we noticed issues with some of the remaining plants. Some had leaves that were flattened, thin or fan shaped; some had curled buds. Immediately we went into diagnostic mode, concerned about the plants we had sold. We sent samples to the University of California at Davis for laboratory analysis.
Our propagation processes were examined and reviewed thoroughly. Was it the seeds, the greenhouse environment, the potting soil, the propagators or other greenhouse visitors who caused these symptoms?
We used seeds from reputable commercial sources, new clean pots and sterilized organic seed-starting mixes and soils. The Master Gardeners who did the propagation and transplanting were trained and experienced. We carefully monitored the seedlings' growth and provided them with the right environment for a strong and healthy start.
The symptoms fit two possible causes. The worst-case scenario was a virus, but herbicide contamination of the potting soil was another possibility. Given the symptoms, tomato mosaic virus and cucumber mosaic virus were the two most likely culprits. But the laboratory results for those viruses turned up negative, so our customers don't need to worry about viruses spreading in the soil. The problem is not viral.
Still, we needed to know what did happen and what we could do to prevent a recurrence next year.
After reviewing our protocols and the growing environment, we suspect that a low-level herbicide such as Clopyralid was present in the transplanting soil. Herbicides used to control weeds in pasture can persist in animal manure, which is then used in commercial soil products. In some cases, the herbicide is present at a level too low to detect, so it may even occur in soil mixes labeled as organic.
Tomatoes are extremely sensitive; minute amounts of these herbicides can affect them.The University of California at Davis laboratory staff and university vegetable experts concurred with our suspicion that low-level herbicide residue in the soil mix was the likely cause of the damage we were seeing.
Many of the stressed plants, transplanted into healthy soil and given adequate water and fertilizer, are faring well. The damage is not transmissible. Even so, we are reviewing and revising all of our protocols from seed starting to sale day.
We had some unusual spring weather that may have impacted our seedlings. Early warm days were followed by nights with very low temperatures. Even in a greenhouse, these temperature swings can stress young seedlings. Tomatoes are sensitive to temperatures below 57°F and require moderately warm to hot weather to produce a crop. Our typical spring was not typical this year.
The Master Gardeners apologize for any problems you have experienced with tomatoes you purchased from us. We are trained to diagnose your gardening dilemmas, but sometimes we have to diagnose our own. Fortunately, our Master Gardener training teaches us where to find reliable, research-based information.
We hope to turn this tomato experience into a “citizen science” initiative. If you purchased tomatoes at our plant sale, please let us know how your plants are doing. We welcome good news and bad. How many of each variety did you purchase? How many are thriving, and how many are struggling or have died? Are your tomatoes in the ground, in a raised bed or in a pot? Did you harden them off before planting, and if so, how? What is your watering and fertilizing routine?
Remember to water your young plants daily until they are established. Give them extra water during very hot weather. Consider applying a 12-12-12 fertilizer before they bloom to give them an extra boost. An additional application of a nitrogen-only fertilizer during bloom will prolong fruit production.
The University of California Master Gardeners of Napa County appreciate your ongoing support for our mission to provide research-based information that helps you succeed in your garden.
Workshop: Napa County Master Gardeners will hold a workshop on “What's Bugging You?” on Saturday, June 18, from 9:30 a.m. to 11:30 a.m., at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Understanding pests and blights that affect your vegetables is key to managing them. Squash that doesn't grow, tomatoes with peculiar markings, artichokes full of earwigs, plants that fail to thrive − all these and more will be discussed. Bring your own problems to show and tell and learn how Integrated Pest Management techniques can help. 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 clients bring sickly plants to the Master Gardener help desk, we ask about conditions in their garden. How often do they water and what method do they use?
For every inch a plant grows, there is probably an inch of roots holding it in the ground and nourishing it. In my experience, clients often water less than plants need. Ten minutes with a drip system three times a week is usually not enough.
When I was training to become a Master Gardener, our class studied how fast water drains through soil. Dry soil has tension; water moves around the surface until it can work its way into the soil. For a demonstration in class, several large tubes were filled with different soil types: sand, mulch, clay, loam and gravel. We watched water work its way down through each soil type and learned that each level had to be saturated before the water moved to the next level.
The same is true in your soil. For deep roots, water deeply.
Many vegetables develop roots that go three feet deep; several, like tomatoes, can have four-foot-deep root zones. Consequently, that is where the water needs to go.
Last year, Napa County Master Gardener Ray Sittig made drainage slits in gallon-size cans, then sunk a can in the soil alongside each of his tomatoes. He filled the cans with water twice a week, and the water slowly seeped into the soil.
Hardpan is another potential problem. Your soil's hardpan is the layer below the topsoil that is impervious to water. In my garden, it is a couple of feet beneath the surface. Hardpan was formed by clay deposited during flooding. Most of the top couple of feet of soil has had mulch, compost, fertilizer and other amendments added. Water penetrates easily but stops when it reaches the hardpan. I often push a length of rebar into the soil to see how deep it goes before hitting hardpan. In my vegetable garden, I continue watering until the rebar goes in easily.
When preparing to build raised beds, some gardeners dig the soil below the bed and work compost into the soil to break up the hardpan. Then the raised bed with its improved soil is built on top.
When I plant tomatoes, I place plastic on top of the soil to conserve water. This barrier keeps moisture in the soil, warms the soil and encourages growth. I have also used clean cardboard, cutting holes in it for the vegetable seedlings.
After planting, apply mulch to the soil surface to retain moisture. My habitat garden, which I don't irrigate, has a heavy layer of mulch. Because of that moisture-retaining barrier, it is still easy to pull weeds. One reason to remove weeds is to keep them from taking water from the plants you want.
If you have a plant problem, bring it to the Master Gardener help desk (see hours below). During the summer season, Master Gardeners also staff a help desk at farmers' markets and garden centers around Napa County. Please bring your plant sample in a plastic bag.
Workshop: Napa County Master Gardeners will hold a workshop on “What's Bugging You?” on Saturday, June 18, from 9:30 a.m. to 11:30 a.m., at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Understanding pests and blights that affect your vegetables is key to managing them. Squash that doesn't grow, tomatoes with peculiar markings, artichokes full of earwigs, plants that fail to thrive − all these and more will be discussed. Bring your own problems to show and tell and learn how Integrated Pest Management techniques can help. Mail-in/Walk-in registration (cash or check only). On-line registration coming soon.
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.
In Lewis Carroll's Through the Looking-Glass, Alice finds herself in the Garden of Talking Flowers. These flowers are quite outspoken, criticizing Alice's hair, demeanor and general ignorance about their way of life. If my roses could talk, they would tell me how grateful they were for all the rain this spring, and perhaps they would give me a hard time about how grudging I was with that commodity last year.
They would be correct. The goal was to survive, but not necessarily thrive. If your roses are like mine, they are proving their resilience by putting forth a lovely display of flowers right now. But what can we do to keep them healthy and productive for the rest of the season?
First, remember to water your roses during the growing season. This is especially important for roses that bloom repeatedly. Roses that bloom only once a season (usually known as "heritage" or "old garden" roses) do not need a great deal of water once they are established. All other roses need regular watering.
You can use basin watering or drip irrigation. The latter method allows you to water several plants at once. Overhead watering can help wash away aphids and other pests as well spores and mildew. Do it early in the day so the leaves have time to dry. Dampness can encourage fungi. Inspect the plant before watering to make sure you aren't washing off beneficial insects such as ladybugs. Mulching around your roses will keep roots cooler so the plant will need less water.
Fertilize right after each bloom cycle to encourage more flowering. First remove the spent flowers (a practice known as deadheading), then fertilize. Dry fertilizers dug into the ground are effective. Add some compost while you're at it.
If you practice basin watering, you might prefer a liquid fertilizer. Some gardeners spray the leaves directly with a hose-end applicator. Again, do it early and watch for beneficials.
The New Sunset Western Garden Book recommends dehydrated alfalfa as an organic fertilizer because it smells better than fish emulsion. It's also a good way to add nitrogen to the soil.
Even roses that flower only once will benefit from a meal after bloom. They won't flower again, but the nutrients will promote growth in the spring.
As the first bloom fades, you may notice black spots on some rose leaves. Perhaps some leaves have lost color in places or have a powdery white deposit. Black spot, rust and powdery mildew are common rose maladies in Northern California, especially after a wet spring. Rust (Phragmidium mucronatum) is a fungal disease that leaves the top of the leaf discolored, with rust-colored pustules on the underside. Powdery mildew (Podosphaera) presents as a white powdery coating on buds, stems and leaves.
At the first sign of any of these problems, remove affected leaves, stems, buds and flowers. Pick up any fallen leaves or flowers to prevent the disease from spreading. Put the affected foliage in your yard-waste bin--not your compost bin--for the same reason. Many of my own rose woes can be traced to inadequate cleanup.
Both the University of California's "Rose Pest Notes" and the Sunset book recommend spraying to combat these pathogens. Spray the leaves, not the flowers. For rust, use a garlic-based or copper soap fungicide. For powdery mildew, use Neem oil or other horticultural oils, a baking-soda mixture, a copper soap fungicide or sulfur.
Black spot (Diplocarbon rosae) produces black marks with irregular edges on the top of the leaf. Often the leaf turns yellow. Horticultural oils can help reduce black spot. Oils can coat insects—including bees—so apply them at the end of the day when the insects have retired for the evening.
Roses are exuberantly beautiful, and to me that is reason enough to nurture them through their ailments. Give them a little care and they will reward you with color and fragrance well into autumn.
Workshop: Napa County Master Gardeners will hold a workshop on “Rose Care” on Saturday, June 4, from 10 a.m. to noon, at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Join the discussion about spring and early summer rose care, issues and solutions. Learn about integrated pest management for common pests and diseases and how to keep your roses healthy during our current drought. 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.
Which is the better choice for controlling pests in our gardens and vineyards: man-made pesticides with their environmental cost or nature's pest squad in all of its beauty?
Consider songbirds. They eat a wide variety of insects, including aphids and snails. They feed on the ground, in mid-air and from vegetation. Especially during their breeding season, songbirds need a high-protein diet. The nutrition they derive from insects is essential for the growth of nestlings and even for the breeding adults. Could there be an easier, more natural way to control garden pests?
To attract these birds to your garden or vineyard, build some birdhouses. Before you begin, take a look at “Songbird, Bat and Owl Boxes” (University of California Publication 21636). The information is aimed at vineyard managers, but it's useful for homeowners as well.
“Songbird boxes should keep birds safe from predators, protect them from weather extremes, and be placed in a manner that is attractive to native species but not to non-native birds,” the publication says. For recommended box styles and building plans, consult conservation groups, specialty stores, woodworkers or the local grape growers' association.
In natural tree cavities, the songbird nesting success rate is 50 to 70 percent. However, boxes mounted on eight-foot T-posts and protected with a PVC sleeve under each box average a 99 percent success rate.
Barn owls were common before agriculture replaced grasslands. By installing nest boxes, you can help increase their numbers to near the level found in their native habitat. Barn owls have exceptional low-light vision, and their hearing is so acute that they can locate prey by sound alone. Adult barn owls kill and eat the equivalent of a large rat, a gopher or a dozen mice every night. How's that for an effective rodent trap?
Barn owls will readily nest in boxes larger than about two square feet. You can build the boxes from materials such as barrels and beehive boxes. Follow the guidelines in the University of California publication or buy a box from a specialty store.
My husband and I built an owl house for the Master Gardener Demonstration Garden at Connolly Ranch in Napa. We will wait until December to install it, since the owls show interest in newly erected boxes around January and lay eggs between February and April.
Owl boxes should be installed 12 to 20 feet above the ground. Add flashing to prevent predators. You can tell that owls have occupied the boxes if you find undigested matter from their prey. Listen for screeching and clicking sounds at night—another sign that owls have taken up residence.
Sadly, young barn owls have a high rate of mortality. Sixty percent die within the first year, and only two percent survive to 10 years. In captivity, they live more than 15 years. Cars and great-horned owls kill both flying and roosting barn owls. Even more reason to build and install owl houses.
There are 25 species of bats in California. These creatures mainly eat insects, including mosquitos, scorpions and centipedes. Bat houses or roost boxes will attract them.
Bat colonies range from a dozen to thousands, with several species sharing the same roost. They are the only mammal capable of flying. Most bat species will feed on crop pests, making them extremely beneficial to farmers. They rely on echolocation and sight to navigate and hunt for food.
Bats live 10 to 15 years and only have one offspring per year. The pallid bat is California's largest bat. Its large ears are so sensitive they can hear insects several feet away. They feed on the ground and catch their prey in the air. Bats can consume their body weight in insects in one night, and they seldom eat beneficial insects.
Due to the loss of natural roosting sites, bats have declined substantially in both species and number. Bat houses can replace the lost roost sites if sited and mounted properly. To keep bats out of reach of predators, mount houses at least 10 feet off the ground and the same distance away from objects that might block the entrance.
Standard bat houses are usually made of plywood and can accommodate about 300 residents. An open bottom serves as both entrance and exit. Do not paint or stain the inside of a bat house. Bat mothers with young prefer houses that receive morning sun and afternoon shade, or no sun.
It can take up to four years for bat houses to be occupied and up to 10 years to build a colony of several hundred.
For many years, humans have been destroying the habitat of these beneficial creatures. Consider taking the time to install houses for some of nature's pest squad so we can help restore our environment one garden or one vineyard at a time.
Workshop: Napa County Master Gardeners will hold a workshop on “Rose Care” on Saturday, June 4, from 10 a.m. to noon, at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Join the discussion about spring and early summer rose care, issues and solutions. Learn about integrated pest management for common pests and diseases and how to keep your roses healthy during our current drought. 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.
Bringing some cheery summer color to your garden is fun and easy. Your favorite nursery, garden center or farmers' market can give you a head start with six-packs and four-inch pots of summer annuals and flowering perennials. Healthy, blooming (or almost-blooming) flowers can change the tone of a porch or deck in a moment.
Pair cool pink and warm coral impatiens with deep blue lobelia to brighten up hanging baskets or pots on shady porches. My summer favorite is a solid bed of cobalt-blue lobelia, providing a cool visual oasis on hot days.
For a different look, azure-blue fountain lobelia produces cascades of flowers on bright green foliage for window boxes and pots. The softer ‘Cambridge Blue' lobelia adds to the palette of summer blues. Bright white and deep cherry-colored lobelia offer even more shade choices for our hot Napa Valley summers.
Choose healthy young plants that are not root-bound and still have some unopened blossoms. With good potting soil, an occasional feeding with diluted fish and kelp emulsion, daily watering and regular deadheading or pinching, lobelia and impatiens will provide color until autumn frost.
Consider colorful but flowerless foliage for shady spots. Light-colored coleus, in all its riotous combinations, grows larger leaves in lightly shaded areas. Leaf color ranges from pink and cerise to salmon and chartreuse. Plant a single coleus in a pot for living art, a whole bed in one dramatic leaf color combination, or a chaotic yet harmonious mix of many varieties.
This year I am experimenting with climbing vines. Climbing Black-eyed Susan (Thunbergia alata) has blossoms like regular bushy Black-eyed Susan but grows five to six feet, quickly covering fence posts and pillars. With fuzzy green leaves and bright yellow-orange daisy-like blooms and big black centers, these vines will, I hope, climb up and cover my front-porch pillars. We are dragging the rocking chairs onto the porch and waiting for the show. Another plus: the blossoms are attractive to butterflies and other pollinators.
Another old-fashioned vine I am planting for the first time is cardinal climber (Ipomoea x multifida). This prolific vine can grow up to 20 feet in one season, completely covering a fence or trellis with five-fingered green leaves and deep-throated cardinal-red flowers. My expectation is that cardinal climber will cover a plain fence and tempt our pollinator friends.
In large or small plantings, white, lavender or pink alyssum will soften and blend areas of color while its sweet honey scent attracts bees and other pollinators. Pair velvety deep-purple petunias with knee-high yellow, orange and red butterfly cosmos for a cheerful porch view or walk.
Carnations, Sweet William and the old-fashioned plants known as pinks, all members of the Dianthus family, can be transplanted now for fragrant cut flowers later. You can also sow or transplant sunflowers (Helianthus annuus) this month. They range from knee high to as tall as an elephant's eye, so you have plenty of choice.
If you have a little space and more time, sow seeds of some flowers now, then again in a month or so. This staggered sowing will produce blooms from early summer until the first frost. In a sunny patch, weeded and watered, try some cheery cosmos or warm-toned marigolds (Tagetes). The ethereal blue love-in-a-mist (Nigella) is also a speedy grower; sow it successively to extend the bloom time. Enjoy the whimsical flowers, then the papery pods and flavorful seeds.
For hot, dry areas, four o'clocks (Mirabilis jalapa) are amazing. Also called marvel of Peru, four o'clocks have large, black bead seeds and bright blossoms in deep pink, sunny yellow, snowy white and carnival stripes. These two- to three-foot plants can survive in the cracks between concrete if they get off to a strong start with spring rains or an attentive hose. Four o'clocks hit their stride in the late afternoon and evening, when their distinctive fragrance wafts through the garden.
Zinnias (Zinnia elegans) win for splashy summer color and endless color choices. Tiny ‘Thumbelina' zinnias in soft pink, yellow and orange are perfect for small pots and pathway borders. Consider ‘Moulin Rouge', a selection of three different tall reds; the popular chartreuse-green ‘Envy';' or the mixed circus colors of ‘Cut and Come Again'. And here's the wonderful thing about zinnias and so many summer flowers: the more blossoms you cut, the more they will grow.
Workshops: U. C. Master Gardeners of Napa County will conduct a workshop on “Home Composting” at American Canyon Senior Center, 2185 Elliott Drive, on Wednesday, May 18, from 6:30 p.m. to 8:30 p.m. Learn the basics of backyard composting and how to turn your yard waste and kitchen scraps into a rich soil amendment or mulch. Learn about tools, techniques and bin types. Register online at www.cityofnapa.org/compost. Or pick up a registration form at the Master Gardeners' office (address below). No phone registration. Directions will be sent when your registration is complete.
U. C. Master Gardeners of Napa County will conduct a workshop on “Growing Ornamentals and Flowers” on Saturday, May 21, from 10 a.m. to noon, at Mid-City Nursery, 3635 Broadway, American Canyon. Learn about the maintenance and care of ornamentals. Master Gardeners will discuss hydrozoning, how to plant for seasonal color year round, and how to encourage pollinators in your garden. 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.
