- Author: Penny Pawl, UC Master Gardener of Napa County
I recently saw an image on a Facebook page devoted to owls that generated a lot of discussion. Some people thought the creature in the image was a butterfly; others were sure it was a moth. I decided it was a moth based on information I had found online. Some said it was an owl butterfly and other commenters wondered if the image was generated by AI. Turns out the AI guess was right.
Did you know that both moths and butterflies are in the same family? The family name is Lepidoptera. Moth species vastly outnumber butterfly species, by about nine to one. Some moths fly during the day and others at night while most butterflies like to fly and feed during the day. A small number of butterflies fly at day's end. Moths are pollinators that feed in the garden mostly at night.
I occasionally find hornworm caterpillars on my tomatoes. Rather than kill them, I move them to open ground, put large containers over them and feed them tomato leaves. The caterpillars mature until they are ready to make a cocoon. At that point they dig or dive into the soil and stay there for two to three weeks, weaving a cocoon around themselves. Then it emerges as a large brown moth with a wingspread of 5 inches.
The moth form of the tomato hornworm is known as the five-spotted hawkmoth (Manduca quinquemaculata). Their preferred nectar is from white flowers, especially white nicotiana, but they also feed on California fuchsia (Zauschneria californica) and manzanitas. The pupa overwinters in the ground and usually emerges in May. It remains a larva for about a month.
I have read that nicotiana has an odor at night that attracts the moths, but I have never seen a butterfly on my nicotiana plants.
The moth larvae are used by many birds to feed their babies each spring and summer. If you are interested in studying moths during the summer months (it's too cold now), I suggest you read this article from the Good News Network on the beauty of moths. And celebrate National Moth Week this summer, from July 20 to July 28.
Ecologists have deemed the Monarch butterfly a keystone species. This designation means that the decline in the number of Monarchs reflects what is happening to other butterflies. The population of Monarchs overwintering in Mexico has dropped by millions. The population on the Pacific Coast is nowhere near what it was in years past.
The magazine Xerces is named after a small blue butterfly that once lived in San Francisco's Golden Gate Park. The Xerces butterfly is now extinct, and its demise is blamed on us. It was last seen in 1943.
It is important not to let other butterflies suffer this fate. What can home gardeners do to help prevent this from happening? We can plant nectar plants and other plants that butterfly, and moth larvae use. Lawns do not yield nectar-producing flowers.
This year, grow a few extra tomatoes so the hawk moth can have a food source. Plant native milkweed, which is a host plant for Monarch butterflies. They lay their eggs on its leaves and the caterpillars eat the leaves. Grow a variety of nectar-producing plants to feed pollinators. Not only will the butterflies and moths thank you, but hummingbirds and bees will, too.
All these creatures are drawn to large patches of flowers so don't just plant one or two. More is better. And they like a diverse combination of native plants. Native plants evolved with native insects and birds.
According to Xerces magazine, oak trees support more varieties of moth larvae than any other type of plant. The Fall 2023 issue of Xerces is devoted to moths, so you might try to find this issue in the publication if you would like more information.
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 8 am to 5 pm. 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.
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: Sue Helms, UC Master Gardener of Napa County
As you look out at your very soggy garden on these winter days, it is normal to dream of future projects. Perhaps you want to revive that old, raised bed with the low soil level. Or you would like to have an easier job of weeding under your rose bushes. Or maybe you want to get rid of that big lawn once and for all.
You can start preparing now to revitalize your soil without having to work on your hands and knees. Sheet composting (also known as lasagna composting) is one way to tackle all those projects.
First, gather your materials or at least plan where to gather them. Whatever your project, you will need cardboard. For a small project, smaller boxes will work. If you are planning on eliminating a lawn, appliance or bicycle boxes will make the job faster. Avoid boxes with shiny ink and be sure to remove any plastic tape.
Now gather compostable materials from your kitchen and garden. You will need both “browns” and “greens.” Brown materials are high in carbon and include dried leaves, shredded newspaper, straw (not hay, which has seeds), dried lawn clippings and even rice hulls (available from feed stores). Green materials are high in nitrogen and include chopped kitchen waste, coffee grounds, tea bags, fresh lawn clippings and garden trimmings. You can freeze kitchen waste if you need to gather it over time.
Do not add weeds with seed heads, perennial weeds with deep tap roots, rose clippings or diseased plant material. Also avoid dairy products, meat and oily foods (including that leftover salad with dressing) as they attract animals. Another no: waste from carnivorous pets such as cats and dogs.
To revitalize a raised garden bed with sheet composting, begin by cutting back any weeds or grass. Wet the soil, then add a layer of cardboard to block the sun from getting to any weed seeds. Top the cardboard with alternating, not-too-thick layers of the brown and green materials, spraying each layer with water. Like making lasagna! You may want to put a piece of burlap on top or perhaps some straw to keep things in place. Do you have places in your garden where weeds return with a vengeance, or where it is difficult to get to the weeds? These areas are ideal for sheet composting. First lay down your cardboard. (Landscape staples can be helpful in holding cardboard in place.) Then you can use the same layering technique as for raised beds, or you can simplify by placing finished compost, purchased from a nursery or municipal composter, on top of the wet cardboard. These layers will prevent weeds from germinating, and after the cardboard decomposes your soil will be much easier to work.
If you want to transform a lawn into a garden site, first cut the grass short. At my house, I used large cardboard boxes from an appliance store, with landscape staples to hold the cardboard in place. A friend helped move compost into place with a wheelbarrow. I spray-painted lines to show where to put the compost and then filled in with straw for walkways. It was a big job, but no pulling of weeds was required.
I wish I could tell you that sheet composting permanently eliminates weeds, but that would be untrue. However, if your soil is naturally hard and full of clay, like mine, you will find that sheet composting transforms it.
Last year, I had trouble seeing where the path was in an area where a larger plant had been removed. With a shovel, it was easy to tell. Even four years after the sheet composting, the area that had received the lasagna treatment was much easier to dig than the pathway. Sheet composting is a great way to create a new garden site, or improve the soil in an existing site, without backbreaking shovel work.
For information about upcoming compost workshops in Napa County, watch for a flyer from your waste-management company or visit the UC Master Gardeners of Napa County website. 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 Hereto receive the free Zoom link. Workshop: Join UC Master Gardeners of Napa County for “Spring Into Summer Vegetable Garden” on Saturday, March 9, from 8 am to 5 pm. 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. 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: Linda St. Claire, UC Master Gardener of Napa County
The harvest of last year's summer and fall crops has ended. I harvested my veggies, elderberries, pineapple guavas and pomegranates. I cleaned up the garden and put away my tools. It was time to let my garden rest.
I'm starting the new year with a renewed sense of joy and hope, and with the goal of a successful garden that will feed me through the spring, summer, and fall. Now I'm ready to plan for the 2024 season.
A bountiful harvest doesn't happen magically. Sure, nature intends for plants to grow, but if we want specific plants and not just weeds, the human touch is necessary. The preparations I make this month are the same tasks I do every January. I'll share this list along with a few tips that will bring you success, too.
I've got 12 raised beds. A few of them are filled with perennial herbs that come back every year. The remaining beds I use for seasonal veggies.
Every year I create a map of what I've planted that year. Why? Because it's important to rotate some crops to avoid soil-borne diseases and insect pests. I use a simple clockwise process, moving tomatoes, potatoes and all the brassica crops, such as cabbage broccoli, cauliflower, Brussels sprouts, turnips, collards, and mustard greens.
Beginning in November, I start dreaming about what I want to plant the following year. I look online to learn what grows best in my climate zone; there's more than one Sunset climate zone in Napa County, so verify your zone.
By January I'm usually receiving catalogs filled with tempting ideas. January is also a good time to visit your local plant nursery to pick up bare-root fruit trees and berry plants. They can go in the ground now.
You can also start seeds indoors now. The Napa County Master Gardeners maintain a planting calendar that lists seed-starting times by season and type of plant.
I purchase a sterile seed-starting soil mix and sterilize some small used containers saved from the previous year. Sometimes I even use little paper cups, perforated for drainage, to start seeds.
I keep the pots in a warm, dark place in the house until the seeds sprout, then I bring them out to a bright light source, like a counter by a window. I plant the seedlings outdoors when the soil temperature is sufficiently warm. Please refer to the Napa County Master Gardener website for more detailed instructions.
I fill my raised beds with compost in the fall, mow the fallen autumn leaves and use them as mulch. The mulch keeps my soil warmer all winter and ensures the weeds don't get a foothold.
If I want to start a new garden bed, I use the “lasagna method.” This technique involves layering sheets of old cardboard and compost in the bed in the fall. First, I lay down some hardware cloth to keep the gophers, moles, rats and voles at bay. Then I add soil, cardboard, and compost in layers. The winter rain and the worms break down the cardboard and mix the compost into the existing clay soil, thus creating a great start. By spring it's usually ready for use although I might add some fertilizer.
Each of my raised beds was started this way. I also use this method to clear weed-infested areas that may have been unattended last year.
I spend a lot of time in my garden during the winter months because my two border collies love to play ball. It's easy to remove dead plants and branches then, too. I use basic sanitary practices to ensure I don't spread pathogens. My pruning tools are clean when I start, and I use rubbing alcohol to disinfect my pruners between different plants. When the weather warms up and the danger of frost has passed, I rake leaves and mulch away from the ground around my fruit trees so the sun can continue to warm the soil.
Turn your irrigation off or, better yet, invest in a smart irrigation controller. A controller app on my phone also lets me know when there will be a saturation skip in the schedule because it's smart enough to know when it has rained. I am also able to start or stop the irrigation depending on the weather.
I use a simple rain gauge to know how much rain we've gotten. If you don't have a smart irrigation controller, you will want to monitor the weather closely. My garden has received nearly 10 inches of rain this season. I could just turn off the irrigation system for the season, but I like to know the controller is doing its job.
These are some of the steps I take each winter to ensure future success in the garden. With these practices, I feel like I can at least give plants a good start. You can do the same.
Pruning Workshop: Join UC Master Gardeners of Marin County for “Winter Pruning of Deciduous Trees” with Nancy Brown on Wednesday, February 7, from 10 am to 1:30 pm, via Zoom. Brown is a professional aesthetic pruner and experienced lecturer. Whether you are pruning a deciduous tree or renewing an overgrown or poorly shaped one, this class will demonstrate best practices for tree beauty and health. Cost is $30. Register for the Zoom link at https://surveys.ucanr.edu/survey.cfm?surveynumber=40751.
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.
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: Tom Hixson, UC Master Gardener of Napa County
Due to my great-great-grandfather's success at planting citrus groves in the 1870s, I was told at an early age that orange juice flowed through my veins. Those historic California orange and lemon orchards were eventually replaced with hundreds of characterless tract homes, but I can resurrect a Proustian memory whenever I smell orange blossoms. That unique scent still ignites memories of dense, glossy green foliage and colorful fruit, a fragrance that etched a cheerful home in my brain and informed a lifelong passion for all things citrus.
There are so many different types of citrus to enjoy, and fortunately for us, Napa Valley's Mediterranean climate lends itself admirably to citrus cultivation. Citrus are in the Rutaceae family (which includes oranges, lemons, grapefruits, pomelos and limes) and are characterized by attractive evergreen foliage and bountiful harvests. They are relatively easy to grow in most gardens and can be maintained as large compact shrubs with minor pruning. With few pests and so many benefits, citrus make a great addition to Napa Valley gardens. If space is an issue for you, be aware that many citrus also perform well in pots on the patio.
But which citrus? An obvious first choice is the Washington Navel, perhaps California's most commonly planted orange. It came to California via Brazil in the 19th century. Prized for its sweet seedless fruit, it blooms in the spring and matures in early winter, just in time for winter holiday celebrations. The Valencia orange is highly valued for juice and produces throughout the spring and summer. For even the most inexperienced gardener, a mini-orchard of Valencia and Washington Navel trees can deliver a near-nonstop supply of fresh juice. And let's not forget the blood orange. As its name suggests, it yields a garnet-red sweet juice, a central ingredient in sangria and a flavorful addition to salads, sauces, and desserts. Perhaps the most utilitarian of all citrus is the lemon. Eureka and Lisbon lemon varieties thrive in the Napa Valley and produce abundant crops once they reach maturity.
The Meyer lemon, with its orange-like scent, is also a favorite in home gardens, but some may find its low-acid flavor deviates from authentic “lemon” taste. The fruits have many seeds and thin skins with very little pith, but they have a limited shelf life so don't show up often in supermarkets. However, you can often find them in small local markets and at the Napa Farmers Market in winter and early spring.
The lime is a universally beloved flavoring for everything from beverages to desserts, as well as a wonderful substitute for lemon juice, especially with seafood and chicken. There are numerous varieties of lime such as Key lime (Mexican lime) and Bearss lime (also known as Persian or Tahitian lime). The so-called finger lime tree produces an elongated finger-shaped fruit that can be used in just about any dish calling for lime.
More exotic citrus varieties to consider include Buddha's hand, noted for its weird finger-like appendages and sweet, tangy flesh; calamansi; and the bergamot orange. Calamansi, also known as kalamansi or calamondin, is native to the Philippines and cultivated throughout Southeast Asia. The marble-sized fruit has seeds but is prized for its delightful floral tartness. I first sampled it in Manila in the form of a memorable calamansi meringue pie. Bergamot, or Citrus bergamia, is a relatively rare citrus native to Calabria, a region of southern Italy. This superfruit is prized for its health benefits. Its unique polyphenols promote healthy cholesterol levels and cardiovascular health. The bergamot's wart-like skin and strong, somewhat bitter taste render it less than appealing for culinary use. However, it is essential in flavoring Earl Grey tea. The French Laundry has used locally grown bergamot in dishes such as Matcha and Orange Délice with Bergamot and Vanilla Sherbet.
Most citrus trees can tolerate light frost, but fruit can be damaged if the temperature remains below 29? for more than 30 minutes. Planting on the south side of the house or garden can reduce the impact of local frost. Stringing incandescent holiday lights through the branches can also help raise the temperature. Citrus thrive in Mediterranean climates so irrigation in the winter and spring is essential, but don't overdo it during summer and fall. As for pruning, most varieties require little more than occasional shaping. Remove dead branches and interior branches to promote air circulation. Overall, citrus plants are easy and rewarding to grow.
Whatever species you select, it likely will have been grafted onto disease-resistant rootstock. Be patient. Most citrus will not produce fruit for the first few years, but once established, the abundance may astound you. It won't be long before your harvest outpaces your needs. But unlike trying to unload surplus zucchini, finding a home for oranges and lemons is never a problem. Friends and neighbors will happily share your excess.
Library Talk: Join UC Master Gardeners of Napa County for “Growing Lettuce Year-Round in Napa County” on Thursday, February 1, from 7 pm to 8 pm, via Zoom. Learn how a seasonal field trial revealed lessons about growing lettuce in Napa County. Register to receive the Zoom link.
Pruning Workshop: Join UC Master Gardeners of Marin County for “Winter Pruning of Deciduous Trees” with Nancy Brown on Wednesday, February 7, from 10 am to 1:30 pm, via Zoom. Brown is a professional aesthetic pruner and experienced lecturer. Whether you are pruning a deciduous tree or renewing an overgrown or poorly shaped one, this class will demonstrate best practices for tree beauty and health. Cost is $30. Register for the Zoom link at https://surveys.ucanr.edu/survey.cfm?surveynumber=40751.
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: Pat Hitchcock, UC Master Gardener of Napa County
During the dark and cold days of January, is there any reason to work in the garden? Add wet soil that should not be disturbed, and you have a trifecta of obstacles for planting. However, this month does present one great opportunity for home gardeners: onions.
If you want to grow nice, large bulb onions, January is prime time to set out onion seedlings. While the organized vegetable gardener will have started seeds last fall, the rest of us will head to local nurseries for onion seedlings in cell packs or order plants online to be delivered in January.
Online sources ship “bare root” seedlings in bundles of 50 or more. You can also plant from seed toward the end of the month, but you will need to allow more growing time or expect to have smaller bulbs. Napa County Master Gardeners do not recommend those bags of onion sets that resemble pearl onions; in our climate these mostly bolt rather than form bulbs.
Last fall, while the soil was still dry, I prepared one of my raised beds for alliumcrops. The alliumfamily includes onions, leeks, garlic, shallots, and chives. In November, I planted one part of the bed with leek seedlings from a local nursery and garlic sets acquired online. I reserved the rest of the bed for planting later.
To plant onion seedlings in the bed now, I will sprinkle granular fertilizer over the soil surface followed by an inch or so of compost. I use my hori hori garden knife (which is like a narrow trowel) to make a slit in the soil, set the seedlings in, then gently push the soil around the roots.
I'll set seedlings 4 to 6 inches apart, allowing room for the bulbs to form later. Depending on the rain, a sprinkling of water from an adjustable hose nozzle completes the planting. I also set up drip irrigation at the time of planting. When the dry season starts, I water the onions once or twice a week.
Onions take a long time to form nice bulbs. Seedlings planted now will mature in late June or early July, even later if you are starting from seed. You will know when they are ready as the bulbs pop up from the ground and the leaves fall over.
When it gets close to harvest time, I stop watering to get the bulbs to dry out a bit. According to the California Master Gardener Handbook, you should not dig onions up too soon if you plan to store them. Note that varieties vary in their storage potential.
Many onion varieties are sensitive to day length. Short-day onions start to bulb when the day is 12 to 13 hours long. Long-day onions need 14 to 16 hours of daylight, and intermediate types require 13 to 14 hours.
In Napa Valley, we hit the 14-hour mark around May 6. Our longest day is June 21, the summer solstice, when we get nearly 15 hours of daylight. In our climate the intermediate-day varieties tend to produce the best bulbs. Seedlings planted in January will have 4 to 5 months to grow before the day length signals them to form bulbs.
Some newer varieties are considered day neutral. These varieties tend to be better for fresh use than for storage.
Frosty weather signals onion plants to bloom if they are larger in diameter than a pencil. As a consequence, seedlings planted in October might not form bulbs if January frosts induce them to bloom. Gardeners call this process vernalization. When small onion seedlings are planted in January, they usually are not affected.
Last January I planted approximately 80 seedlings of intermediate-day onions. They were a mix of three varieties: white Super Star, yellow Candy, and Red Candy Apple. Very few bolted and I had a bumper crop in June.
Onions don't last forever in storage. Some of mine sprouted or got soft before I could use them, but the last four onions are on my kitchen counter now. I consider that a successful result and I am looking to repeat it this year.
Workshop: Join UC Master Gardeners of Napa County for “Pruning Deciduous Fruit Trees” on Saturday, January 27, from 10 a.m. to noon at Las Flores Learning Garden, 4300 Linda Vista Avenue, Napa. Learn the whys and hows of winter pruning, techniques, and tool care. Workshop is indoors but dress warmly for outdoor activities, weather permitting. Space is limited. Register here.
Library Talk: Join UC Master Gardeners of Napa County for “Growing Lettuce Year-Round in Napa County” on Thursday, February 1, from 7 pm to 8 pm, via Zoom. Learn how a seasonal field trial revealed lessons about growing lettuce in Napa County. 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 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.