As the end of August approaches, we gardeners are savoring our harvest of tomatoes, peppers, zucchini and other summer bounty. Days are getting shorter and the light is starting to change, signals of a shift in the seasons. Cool-season vegetables are just on the horizon.
With autumn approaching, we need to be thinking about amending our gardens and getting them ready for planting the kinds of vegetables that thrive in cool weather.
Many Napa Valley microclimates are conducive to these cool-loving edibles. Depending on the crop, the best planting time for seeds and nursery seedlings ranges from late August to early September.
Vegetables that do well in fall and winter include cole crops (brassicas), root vegetables and leafy greens. Among the brassicas, consider growing cabbage, Brussels sprouts, cauliflower and broccoli. Root vegetables to plant now include turnips, carrots, radishes, parsnips and beets. As for leafy vegetables, late summer is the ideal time to start lettuces, chard, kale and bokchoy. Asparagus and potatoes can also be planted now.
Some of these cool-season vegetables are “two-for-ones,” like beets and turnips. We can (and should) eat both the roots and the nutritious greens. Most of these fall and winter edibles are rich in vitamins and antioxidants.
If you are planting from seed, don't delay. Seeds will sprout quickly in late summer's warm soil, and your seedlings will get off to a good start before the weather cools. You can plant nursery seedlings now and into September; local nurseries have a good selection now.
Napa County Master Gardeners have a useful planting calendar, which you can find at http://ucanr.edu/sites/ucmgnapa/Gardening_Books/.
I grew broccoli, spinach, chard and leeks successfully when I lived in Grass Valley, with its cool nights and warm days. These crops also do well when grown in autumn in Napa Valley.
Companion planting is a great way to use space wisely if you have only a small garden bed or are using containers. I personally have a small space and use containers. Broccoli and baby bokchoy or spinach work well together. You can plant herbs and scallions or leeks together, or beets and radishes with lettuce.
Be sure to amend your soil with compost before planting cool-season vegetables to ensure a bountiful future harvest.
Free workshop: Napa County Master Gardeners will conduct a workshop on “Home Composting” on Saturday, September 6, from 9:00 a.m. to 10:00 a.m. at the Yountville Community Center. Learn how to turn yardwaste and kitchen scraps into rich compost to use as a soil amendment or mulch in your garden. The workshop is free but Pre-registration is required. No phone registrations are accepted. You will receive a confirmation and directions after registering. Questions? Call (707) 257-9200.
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. Napa County Master Gardeners ( http://ucanr.org/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.
The European honey bee came to North America with the first settlers. These bees are native to Europe and Turkey. Currently they are suffering from a disease called “colony collapse,” which causes whole hives to die off.
Scientists are still studying this phenomenon. However, long before the settlers arrived, our native bees, known as solitary bees, were fertilizing native plants.
These bees and plants evolved together. The bees do not produce honey, so they have not been domesticated. But they still visit our gardens and, with some help, they can work for us.
In an effort to help solitary bees, I leave areas of my garden bare, with no mulch or other covering. Nor do I turn this soil. The area is full of holes. Many solitary bees and bumblebees use the ground for nests. Most of them nest alone, providing food and a safe nest for the next generation.
Bumblebees are a little different. They also nest in the ground but usually with a queen. On one occasion, I was able to watch a bee making her nest. She drilled into the soil and kept flying back and forth with nectar or insects. Then one morning the nest disappeared. She had covered it up and let nature take its course until the following spring.
About the same time I heard about nesting blocks of wood for the mason bees that also pollinate our gardens. I had several 4 x 6 pieces. I had them cut to about 12 inches and drilled holes in them. I put them on hangers and left them near fruit trees and blooming flowers.
Some bees did make nests in these holes. They put food for their eggs into the cells. The food varies with the species: some use insects, some use cut leaves and others pollen. They then lay their eggs and put more food between each egg. When the eggs hatch, there is food for them immediately. Once they mature, they emerge from the cell as new bees that will then pollinate this year's crops. They seem to emerge when the fruit trees bloom, typically in March or April.
In my wood pile, I found an interesting piece of wood that I took out and saved. The holes drilled into this piece are of varying size—some 3/8 inch, some 5/8 inch. I had a small roof attached just for aesthetics and it is now attached to my garden fence. This spring I saw a beautiful small bee making a nest in one of the holes. Each hole is sealed with mud. When I counted just a few days ago, there were 52 cells, 39 of them are sealed with mud. This is the best usage I have ever seen.
I have many varieties of flowers for these bees, including lavender and salvia. Bumblebees love both. Not long ago I saw a bumblebee so covered in pollen he could hardly take off. Eventually he made it home.
Paper wasps have lived here many years. I leave them alone because they collect insects for their paper cells and help control bad bugs. They probably get some good ones, too, but that is nature. A few summers ago, I was watching a paper wasp nest on my front porch and decided that the six bees sitting there were done with it and maybe I should remove it. Just then, a much larger wasp flew in and fed each of the other wasps, just as birds do with their young. I was so impressed that I did not touch that nest.
You, too, can help our native bees and wasps. Plant lots of blooming plants, avoid using pesticides in your yard, and leave some soil uncovered. Be aware that all the creatures that fly by your nose are not harmful. Be curious, watch nature and follow her lead.
If you are interested in learning more about native bees, take a look at Field Guide to the Common Bees of California by Gretchen LeBuhn and Noel Badges. Websites can also provide lots of information on building mason bee nests.
Workshop: Napa County Master Gardeners will conduct a workshop on “Cool Season Veggies” on Sunday, August 17, from 2 p.m. to 4 p.m., at the Yountville Community Center, 6516 Washington Street, Yountville. Napa County Master Gardeners will conduct a workshop on “Cool Season Veggies” on Saturday, August 23, at U.C. Cooperative Extension, 1710 Soscol, Napa. Grow your own vegetables even when days are short and nights are cold. Learn which vegetables thrive in cooler temperatures, how to protect them from heat when they are getting started, and how to time planting to ensure months of harvest. To register for the Napa workshop: Online registration (credit card only) Mail in registration (cash or check only).
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. Napa County Master Gardeners ( http://ucanr.org/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.
Napa County Master Gardeners welcome the public to visit their demonstration garden at Connolly Ranch on Thursdays, from 10:00 a.m. until noon, except the last Thursday of the month. Connolly Ranch is at 3141 Browns Valley Road at Thompson Avenue in Napa. Enter on Thompson Avenue.
Although each of these claims may be true, for me the answer is simpler: I grow food for my table. As I have become a more knowledgeable vegetable gardener, I have wanted to increase the variety of crops I grow and to harvest year round.
Plants are adapted to grow at specific temperatures. Some annual vegetables prefer warm weather; others perform best when it’s cool. Warm-season plants grow best in daytime temperatures of 65°F to 95°F. They thrive when night-time temperatures stay above 50°F. Most of them tolerate high temperatures but are damaged or killed by frost. Cool-season crops prefer cooler soil and air (55°F to 75°F), perform poorly when temperatures are high, and tolerate or are improved by frost.
When researching average temperatures for Napa County, I found some useful graphs on the Weather Channel’s website (www.weather.com). From May to October, our average lows range from 49°F to 55°F, while average highs for the same months are 76°F to 83°F. The months of November to April see average lows of 39°F to 45°F degrees, and highs of 57°F to 71°F. If our weather is not too extreme, we can accommodate cool-season vegetables six months a year and warm-season vegetables during the other half.
So growing vegetables year-round in Napa County is just a matter of timing: growing the right plants at the right time.
Year-round vegetable gardening uses soil intensively, so maintaining fertility is critical.
Soil is comprised of four principal components: minerals, organic matter, air and water. Minerals and organic matter make up about half of the volume of typical California soils, with minerals being by far the largest part. Soil minerals are basically decomposed rock. The size of the particles determines whether your soil is sandy (large particles), loam or clay (small particles).
Organic matter consists of decomposing plant and animal residue, living soil organisms (earthworms, fungi, bacteria) and the substances they synthesize.
The other half of the soil’s volume is the pore spaces between the solid particles. In soils with ideal moisture content, the pore spaces are about half water and half air. Typical soil by volume will be about 45 percent minerals, 25 percent water, 25 percent air and 5 percent organic matter.
Soils can be coarse and sandy or fine and clay-like. Their texture reflects the mineral content, which is difficult to alter. However, increasing the organic matter in sandy or clay soils changes the way the soil aggregates, or clumps, and improves the conditions for growing plants.
Although the living organisms in soil comprise a small percentage of its volume, mounting scientific evidence suggests that these organisms play a significant role in helping plants fight disease and pests. Many soil microorganisms live in beneficial relationships with roots. These organisms digest organic matter over time and need air and moisture to survive. Even when you don’t have a crop in the ground, you need to provide an environment that encourages this soil life. In a year-round vegetable patch, you should add compost or other organic amendments at least twice a year, or each time a new crop is planted.
Our California soils tend to be low in nitrogen, a major nutrient for growing plants. Your soil may also be lacking in other nutrients. Year-round vegetable gardening can quickly deplete soil nutrients. If your organic amendments are not relatively high in nutrients, you will need to fertilize several times a year. Although you can use synthetic fertilizers, they can harm the natural soil life. Use all fertilizers carefully, following package directions and never using more than recommended.
Plants interact with soil in different ways. Just as farmers do, home gardeners should rotate crops to prevent soil-borne diseases from getting established and to foil pests that prefer specific crops.
So here’s 12-month gardening in a nutshell: plant the right plants for the season;feed the soil with organic amendments; use fertilizers as needed; and rotate plants. Then proceed to enjoy homegrown food year round.
Workshop: Napa County Master Gardeners will conduct a workshop on “Success with Veggies All Year Long” on Saturday, January 25, from 9:30 a.m. to 11:30 a.m., at the University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Learn how to keep your garden soil healthy and productive, find out which vegetables to plant in what months, and be introduced to many reliable resources. Online registration (credit card only)Mail in registration (cash or check only)
Napa County Master Gardeners welcome the public to visit their demonstration garden at Connolly Ranch on Thursdays, from 11:00 a.m. until 1 p.m., except the last Thursday of the month. Connolly Ranch is at 3141 Browns Valley Road at Thompson Avenue in Napa. Enter on Thompson Avenue.
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. Napa County Master Gardeners ( http://ucanr.org/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.
