- Author: Jane Callier, UC Master Gardener of Napa County
One of the joys of being a Master Gardener is working with a team to produce an educational event for home gardeners. To that end, Master Gardeners are growing gourds, pumpkins and Indian corn for our Fall Faire on Saturday, September 30. Find a link with more information at the end of this column.
Celebrations at the end of the growing season have been part of life for millennia. Although today's UC Master Gardeners disseminate scientifically proven methods of growing and harvesting plants, science didn't always have much of a place in historical harvest rituals.
In times past, after a long growing season and hard work, holding a harvest festival was a way of giving thanks for the successful crops. A good harvest ensured there would be enough food during the short, dark days of winter.
This tradition of giving thanks has been practiced since pagan times. The “harvest moon,” the full moon that occurs closest to the autumnal equinox, was often the impetus for a celebration. As part of the festivities, baskets of fruit and food would be displayed for decoration. Known as a cornucopia, or horn of plenty, these baskets were shaped like a goat's horn.
There are several explanations in Greek and Roman mythology for the origin of the cornucopia, but all have to do with breaking off the horn of a goat or horned river god and the abundance, nourishment, good luck, and prosperity derived from it. The cornucopia embodies everything about harvest time, so it makes sense for this symbol of abundance to be associated with giving thanks.
Even Hades, the god of the underworld, who is said to have given agriculture and spiritual wealth to mortals, has been depicted holding a cornucopia. The best-known celebration of thankfulness in American culture is, of course, Thanksgiving.
Up until the 20th century in Great Britain, most farmers celebrated the end of the harvest with a big meal called the harvest supper. This event took place after the last patch of corn or wheat had been harvested. It was considered bad luck to be the individual who performed this task, so farmers would race against each other to be the first to finish.
This superstition was so prevalent and entrenched that workers resorted to throwing their sickles at the last stand of corn to avoid direct contact with it. In other areas, reapers would take turns being blindfolded to sweep a scythe until the last stand was cut down.
Napa County Master Gardeners are growing two varieties of ornamental corn for our fall celebration. Colorful Indian corn with its traditional calico pattern of red, gold, black and yellow is one of the types. Indians did not eat this corn fresh but ground it into meal for use. It is very starchy and so hard that eating it raw can result in broken teeth. The other variety we are growing is a hybrid in shiny pastel shades of blue, pink, ruby and green.
We are also growing several varieties of gourds for the Fall Faire. Growing decorative gourds is a lot of fun, and you can find many beautiful examples of artist-decorated gourds online. Even a not-so-talented individual can have success decorating and painting dried gourds.
Dried gourds can be made into a wide variety of useful objects, including utensils, cups, bottles, scoops, ladles, and birdhouses. Many cultures have made musical instruments from gourds. And there's nothing better than a luffa gourd as an exfoliator in the bath.
Gourds are generally easy to grow from seed but have some cultural requirements. They need a lot of space, ample water (about an inch a week) and regular feeding. Gourds start out on the ground but eventually require trellising. It's best to install trellises before the plants grow too large so you don't disturb the roots. They need full sun and like hot weather.
One of the gourds Master Gardeners are growing for the Fall Faire is the Tennessee spinning or dancing gourd, a tiny, charming little gourd. It is only about two inches tall and can be used as a toy top for children. These gourds may be small, but the plant, like other gourd plants, is huge.
We are also growing luffa, which requires some patience to clean. When fully mature, they must be skinned to reveal the coarse netting material inside. This material is a chockful of seeds that must be removed.
Among the other hard-shelled decorative gourds are the speckled swan gourd, a large gourd with a round base and swanlike neck and head; giant bottle gourds; bushel basket gourds, their size being that of their namesake; dipper gourds with long, straight necks; and birdhouse gourds. All of them are fun to grow and decorate. Join us at the fair to see some of them.
Fall Faire: Join UC Master Gardeners of Napa County for “A Gardening Science Fair for All Ages” on Saturday, September 30, from 1 pm to 4 pm at Las Flores Community Center, 4300 Linda Vista Avenue, Napa. Get more details here.
Library Talk: Join UC Master Gardeners of Napa County for a free Napa Library talk on “Lawnlessness: Thinking Beyond Turf” on Thursday, October 5, via Zoom. Learn about lawn alternatives that are attractive, lower maintenance and drought tolerant. Register here to receive the Zoom link.
Help Desk: The Master Gardener Help Desk is available to answer your garden questions on Mondays and Fridays from 10 am until 1 pm 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: Penny Pawl, UC Master Gardener of Napa County
I have two plants in my garden that are magnets for pollinators and butterflies. Both plants put on quite a flower show and are drought tolerant. Given our ongoing issues with water, this latter feature should be priority for all of us.
Some bird or other creature planted Jupiter's beard some years ago in my garden. I did not know what the plant was, but I noticed that there was always a crowd of bees buzzing around the blossoms.
Over the years the plant has reseeded and slowly spread over one of my garden beds. I am amazed by the number of pollinators who visit to enjoy the nectar on the flowers. The visitors include bumblebees, honeybees, small butterflies of several types and of course the big butterflies I love to watch, the Swallowtails. Hopefully the Monarchs will soon stop by.
Jupiter's beard (Centranthus ruber) is a drought-tolerant perennial that grows up to three feet tall. It typically has red flowers but some varieties have pink or white blooms. The red blossoms attract more creatures.
The plant is also known as fox's brush, red valerian, keys of heaven, pretty Betsy and spur valerian. It is short-lived but reseeds so well that it can be invasive. Jupiter's beard has naturalized in many places in Europe and is considered a Mediterranean plant.
I tried saving seed this year but it is difficult. To ensure repeat bloom, I remove the dead flowers daily. But while doing so, I watch all the creatures getting nectar from the fresh blossoms.
During the winter I cut the plants back to the ground. They survive the winter and emerge the following spring to feed another generation of pollinators.
The other pollinator plant I love is Clarkia (Clarkia amoena). It is also known as farewell to spring. This annual plant is native to the Pacific Northwest. It is named for Captain William Clark of the Lewis and Clark expedition. There are 40 species in the Clarkia genus, with most native to the western United States but one native to South America.
Initially I purchased a small package of seed online and spread it in my yard. Over the years it has spread itself. However, the seeds pods are easy to harvest if you want to save the seed and sow it in the fall for spring bloom.
Thanks to last spring's rains, my Clarkia put on a beautiful show along with red Asian poppies and California native poppies. During the bloom, the pollinators were busily gathering nectar from every flower. I love to watch this process. It seems that nature itself is helping all its creatures.
I have harvested and saved seeds from Jupiter's beard and Clarkia, but Jupiter's beard is harder to do. I waited until the head of the blooms was mostly clear of flowers and I could see the seed pod. Then I put them in a container in my hothouse to dry with the flower heads pointed down. Once the flower heads were dry, I cleaned the seed and saved them.
Alternatively, you can dig up this perennial when it's dormant and replant it wherever you wish. Give it lots of room as it will spread.
Saving Clarkia seed is much easier as the long stem has small seed pods all along it. I cut the plants back when they finish blooming and put the seed pods in a container. As the pods ripen, they open and the seeds fall out. I use a small kitchen strainer to clean them. The seeds fall through and I discard the debris outside.
Plant Clarkia seeds in the fall. I wait until October when the days are getting shorter and hopefully there may soon be rain. After spreading the seeds, I walk on them to press them into the soil. Then nature nurtures them until spring.
Gardening with the Masters: Join UC Master Gardeners of Napa County on Saturday, September 16, from 10 am to noon, for a workshop at Ole Health Garden, 300 Hartle Court, Napa. Children accompanied by an adult are welcome. Class size is limited. Register to attend.
Fall Faire: Join UC Master Gardeners of Napa County for “A Gardening Science Fair for All Ages” on Saturday, September 30, from 1 pm to 4 pm at Las Flores Community Center, 4300 Linda Vista Avenue, Napa. Get more details here.
Library Talk: Join UC Master Gardeners of Napa County for a free Napa Library talk on “Lawnlessness: Thinking Beyond Turf” on Thursday, October 5, via Zoom. Learn about lawn alternatives that are attractive, lower maintenance and drought tolerant. Register here to receive the Zoom link.
Help Desk: The Master Gardener Help Desk is available to answer your garden questions on Mondays and Fridays from 10 am until 1 pm 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: Rainer Hoenicke, UC Master Gardener of Napa County
Most likely, you have been to a garden center and made impulse purchases of plants that struck you as particularly attractive. I've done so myself. Even if you read the label carefully, that plant may lose its luster after a few weeks or decline it's ready for the compost bin. Sometimes I only find out years later why my kangaroo paws, jacaranda and avocado died an untimely death.
Over the years, I have learned that, as long as the plant shows some green color, it may be worth investigating why it is ailing. The Master Gardeners' Help Desk can sometimes assist with that research.
Unless the plant has an incurable disease, consider digging it up and finding a more suitable spot for it—even a temporary home in a clean container with fresh potting soil. I once attempted to grow a bougainvillea that I had inherited from a Southern California friend. I had it in a four-gallon pot in a sunny location against the house, but one 27°F night killed it. A mature vine just two blocks south of us survived just fine.
I attempted to grow tomatoes in various sunny locations in my Napa garden for at least three years before realizing that most of those areas were infested with a soil-borne fungus. No wonder I had trouble harvesting a bountiful crop.
These failures taught me a few lessons. Rotating crops in the vegetable garden is a sound cultural practice. Vegetables in the same plant family (like tomatoes, eggplants and peppers) should not be grown in the same spot year after year. Put them on a three-year rotation to discourage soil-borne diseases from getting a foothold.
It's also essential to protect sensitive or tender plants from weather extremes. My new bougainvillea survived this past winter with a bit of frost protection on chilly nights, and my hostas are now vibrant in full shade without any direct sun.
Climate change is causing more extreme weather events that can challenge our plants. It may be time to rethink what we can successfully grow in Napa County. In my own garden, I am testing plants from other Mediterranean climates (South Africa, Southwestern Australia, Chile, North Africa, Western Asia and Southern Europe) to see how well they do during heat waves and winter downpours.
Most plants from these regions require good drainage. I've had success with trees and shrubs that don't thrive in clay soils by growing them in raised beds or containers. I've successfully grown tender plants that reportedly would not thrive or survive in Sunset climate zone 14 or USDA climate zone 9. By providing frost protection during their first few years, I can keep the plants safe until they become hardier.
I prepared my own well-draining peatless planting mix to try growing shrubs in the Protea family, so far with reasonable success. A Sacred Flower of the Andes (Cantua buxifolia) that I planted from a four-inch pot last October in a spot with afternoon shade is now five feet tall. From March through June, it was covered with brilliant magenta blossoms that hummingbirds loved.
I am considering using this plant in a low hedge to visually separate the shed area in our orchard. It seems to be much more disease resistant than boxwood and, like boxwood, it can easily be trimmed into hedges and topiaries.
I intend to acquire more unusual plants – perhaps even some trees – in the future to find out how they like different parts of my garden. I'll keep good notes on how they are doing, even in the most challenging spots of dry shade in my backyard.
Food Growing Forum: Join UC Master Gardeners of Napa County for “Rooting for Root Vegetables” on Sunday, September 10, from 3 pm to 4 pm via Zoom. Root vegetables grow readily from seed sown in September's warm weather, just as the rest of the garden starts to wane. Beets, carrots, turnips and other root veggies benefit from cooler weather, getting sweeter and juicier as temperatures drop. Learn how to plant and care for these root crops, which you can harvest well into fall. Register to receive the Zoom link.
Gardening with the Masters: Join UC Master Gardeners of Napa County on Saturday, September 16, from 10 am to noon, for a workshop at Ole Health Garden, 300 Hartle Court, Napa. Children accompanied by an adult are welcome. Class size is limited. Register to attend.
Fall Faire: Join UC Master Gardeners of Napa County for “A Gardening Science Fair for All Ages” on Saturday, September 30, from 1 pm to 4 pm at Las Flores Community Center, 4300 Linda Vista Avenue, Napa. Get more details here.
Help Desk: The Master Gardener Help Desk is available to answer your garden questions on Mondays and Fridays from 10 am until 1 pm 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: Genever Fox, DVM and Master Gardener of Napa County
Many of our commonly cultivated house and garden plants contain toxins. During my 35-plus years in veterinary practice, I treated many patients for either known or suspected toxic plant ingestion.
For the most part, plants that are poisonous to pets are equally dangerous to children. Once people are aware of this potential danger, they can reduce the risk to pets by reducing exposure and to children by educating them not to ingest plants in the house and yard.
Fortunately, most toxic plants taste bad, and this generally limits how much dogs and cats will eat. However, dogs, especially puppies, are indiscriminate about what they will taste, which increases their risk of plant poisonings. Cats in general are less likely than dogs to randomly chew on plants. However, I have noticed that many indoor cats will nibble or chew on house plants and dried plant material.
For veterinarians, one plant stands out by far as a known or suspected source of toxicity: marijuana (Cannabis sativa). While a dog might chew on a backyard plant, most exposures are via ingestion of either dried plant material or “edibles.”
Symptoms of Cannabis toxicity can be profound and disturbing and include disorientation, loss of balance, lethargy, slow heart rate and tremors. These symptoms resemble many other toxicities, so tell your veterinarian if you know or suspect that your pet ingested a cannabis product. Fortunately, with a prompt diagnosis and appropriate care, most patients survive. A drooling pet, often a cat, is another common presentation of plant toxicity in veterinary practice. This symptom can result from the pet chewing on plants that contain oxalic acid crystals. These crystals are found in many houseplants, including dieffenbachia, philodendron, pothos (Epipremnum aureum), peace lily (Spathiphyllum), elephant ear plant (Caladium spp.) and arrowhead plant (Syngonium podophyllum). The crystals can cause intense irritation and pain and swelling of the mouth and throat.
Lilies (including Easter lily, tiger lily, and ‘Stargazer' lily) and some daylilies (Hemerocallis spp.) are uniquely and severely toxic to cats. Ingesting even a small portion, including cut flowers, causes kidney injury and can lead to kidney failure. Keep indoor cats away from any lilies in the home, both potted plants and cut flowers.
Sago palms (Cycas revoluta) are common in Napa County, both as in-ground and potted plants. They contain a toxin found throughout the plant but especially concentrated in the seeds (nuts). I have seen dogs, usually puppies, with gastrointestinal symptoms (vomiting, diarrhea, abdominal pain) from chewing on this plant. Without prompt and appropriate treatment, they can develop severe liver toxicity, which can be fatal.
Grown as a showy ornamental in mild climates, and commercially for its oil, castor bean plant (Ricinus communis) is now recognized by the California Invasive Plant Council (https://www.cal-ipc.org/) as an invasive species in southern and central California. The seeds (beans) are extremely toxic, containing high concentrations of ricin, a potent poison. The dogs I saw in my practice had symptoms that resembled those of severe parvovirus infection: bloody vomit and diarrhea, marked dehydration, weakness, and toxic shock. Ingesting only a few beans can be fatal to dogs and humans.
Many common plants contain toxins that affect the cardiovascular system. These include foxglove, tulip and narcissus bulbs, lily-of-the-valley, certain milkweeds (Asclepias spp.) and oleander. Ingestion of very small amounts of any of the plant parts can cause gastrointestinal and heart-related symptoms that are potentially fatal.
Wild mushrooms can also be toxic, even deadly. While many mushrooms are not toxic, identifying those that are safe to eat is best left to experts. Never eat wild mushrooms unless they are identified as safe by a trusted expert. Scan your yard for wild mushrooms and remove them prior to letting your dog out. When walking your dog in an area with wild mushrooms, keep your pet on leash to prevent any foraging. Never feed your dog mushrooms or food containing mushrooms; you do not want your dog to think of mushrooms as food.
If you're a pet owner, learn to identify toxic plants in your yard and home before a problem occurs. The ASPCA keeps a list with pictures of both toxic and non-toxic plants. Master Gardeners of Napa County can also help you identify a plant if you submit samples and/or pictures to our Help Desk (address below).
If you suspect your pet ingested a toxic plant, call your veterinarian immediately and be prepared to take your pet in for emergency treatment. Bring samples of the plant with you and pictures of the entire plant if possible. You can also contact Animal Poison Control directly at 888-426-4435.
For more comprehensive information, consult these online publications:
UC ANR Publication 8564 Poisonous Plants
Veterinary Partner offers articles written by veterinarians on many common plants that are toxic to pets.
Library Talk: Join UC Master Gardeners of Napa County for a free Napa Library talk on “Save Your Leaves, Save the Planet!” on Thursday, September 7, from 7 pm to 8 pm via Zoom. Learn how to use organic materials from your kitchen and garden to enrich the soil and fight climate change. Register here to receive the Zoom link. Guided Tree Walk: Join UC Master Gardeners of Napa County for a free guided tree walk in Napa's Fuller Park, Oak Street and Jefferson Street, on Friday, September 8, from 10 am to noon. Space is limited to 15 and each person attending must register separately. Register here. Food Growing Forum: Join UC Master Gardeners of Napa County for “Rooting for Root Vegetables” on Sunday, September 10, from 3 pm to 4 pm via Zoom. Root vegetables grow readily from seed sown in September's warm weather, just as the rest of the garden starts to wane. Beets, carrots, turnips, and other root veggies benefit from cooler weather, getting sweeter and juicier as temperatures drop. Learn how to plant and care for these root crops, which you can harvest well into fall. Register to receive the Zoom link. Help Desk: The Master Gardener Help Desk is available to answer your garden questions on Mondays and Fridays from 10 am until 1 pm 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 of the problem. For best results, attach a photo of the plant. You may also leave a voicemail message with the same information.




- Author: Donna Woodward, UC Master Gardener of Napa County
Kale has the reputation of being a “superfood.” This is one of those vague terms scorned by experts, dietitians and scientists but loved by marketers.
Kale is, indeed, high in vitamins and fiber. It seems to have entered the American consciousness sometime in the 1990s, when we began to pay more attention to nutrition. Whether it's tasty is another source of controversy, almost as divisive as politics. The answer depends a lot on how it's prepared. If you're not currently a fan, I recommend you find some good recipes.
Due to kale's popularity and vaunted health benefits, the Master Gardeners Field Test Committee thought the vegetable would be a good subject for a field trial. We would grow three varieties in our gardens to see which did the best and which we liked best.
Kale is a cool-weather crop, so we planted in late summer for a fall to winter harvest. One variety we chose was Black Magic, an Italian kale composed of long, dark green, very crinkly leaves. Another was Red Russian, which has softer, lighter green, frilly leaves with a red stem.
These two varieties are common types available from many seed sellers. We purchased them from Territorial Seed Company.
For the third variety, we wanted something more exotic, so we turned to Kitazawa Seed Company, now sold under True Leaf Market. We chose Ethiopian kale, also known as mustard kale, Abyssinian mustard, African kale and Highland kale. It certainly sounded exotic. I was a bit disappointed to find that it looks a lot like the Italian variety, only softer and less crinkled.
We were curious about the best time for seeding so we tried different starting times. We all began with planting seeds in cell packs, but we spread our starting times over two months, from early August to early October.
For August and September starts, the seedlings were ready to go into the ground five to six weeks after seeding. The seeds started in October struggled through the winter and barely stayed alive until spring. They eventually took off and did well, but they would have done better If we had just waited until early spring to plant the seeds.
Planting for a fall harvest is all about timing. Unlike in spring, when several months of mild temperatures allow plenty of leeway for planting, the window of opportunity for planting fall-maturing crops is small. August is still too warm to set out cool-weather crops, so they must be started in sheltered conditions. Then the seedlings must go in the ground in time to allow for vigorous growth before the days get too short.
Our Napa Valley climate presents some challenges because the weather usually remains warm well into October. Many of us still have tomatoes, peppers and eggplants in our vegetable beds through October. So it's hard to get cool-weather seedlings planted and growing before the so-called “Persephone period” from November 20 to January 20, the shortest days of the year. During this period there is not enough sunlight for plants to thrive. The seeds we started in August produced harvest-ready leaves (8 to 10 inches) by November, but eventually many of the plants began to go to seed or were besieged by insects. The seeds started in early September produced seedlings for planting by mid-October. A month later, they were ready to harvest. In fact, by that time they had overtaken the earlier planting in size (12 to 24 inches) and vigor. They held on through the winter and continued to grow in spring.
Conclusion: Early September is the best time to start kale seeds in our climate, and mid-October is ideal for transplanting. At least that was the case in 2022.
As for flavor, there was no consensus. Some people loved Black Magic; others found it tough. I thought it was the most flavorful, but it requires some treatment to use it raw in salads, such as massaging the leaves with oil. Both Russian and Ethiopian kales are softer and can be prepared in any number of ways.
In a tally of which type we would grow again, 75 percent of trial participants said yes to Italian; only 25 percent would replant Russian, and we had an even split on Ethiopian.
Overall, kale is a hardy and easy-to-grow plant. Some participants reported problems with aphids, which are easy to miss because they hide on the underside of leaves. If you catch them early, you can wash them off with a hose and avoid damage to the leaves.
Birds love kale, but floating row covers will protect the plants from these predators. Only one person reported snail damage. Kale leaves grow upward and are not usually in contact with the ground, so the snail-eaten plants may have been young. Snail bait containing iron phosphate can provide protection against snails and slugs.
Workshop: Join UC Master Gardeners of Napa County for a workshop on “Welcoming California Native Plants into Your Garden” on Saturday, August 26, from 10 am to noon, at Las Flores Learning Garden, 4300 Linda Vista Avenue, Napa. Learn compelling reasons to include native plants in your garden, when and how to plant them, and how to care for them. Attendance is limited. Register here.
Library Talk: Join UC Master Gardeners of Napa County for a free Napa Library talk on “Save Your Leaves, Save the Planet!” on Thursday, September 7, from 7 pm to 8 pm via Zoom. Learn how to use organic materials from your kitchen and garden to enrich the soil and fight climate change. Register here to receive the Zoom link.
Guided Tree Walk: Join UC Master Gardeners of Napa County for a free guided tree walk in Napa's Fuller Park, Oak Street and Jefferson Street, on Friday, September 8, from 10 am to noon. Space is limited to 15 and each person attending must register separately. Register here.
Help Desk: The Master Gardener Help Desk is available to answer your garden questions on Mondays and Fridays from 10 am until 1 pm 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 of the problem. For best results, attach a photo of the plant. You may also leave a voicemail message with the same information


