The Persephone Period
By Helen Dake, UC Master Gardener of Napa County
For years, my husband and I grew successful summer gardens. We were so successful that for a while we set up an “honor system” farmstand for charity on the road in front of our house. We supplied neighbors and walkers-by with tomatoes, peppers, squash and other summer vegetables.
Yet in spite of these accomplishments, we could not seem to grow a winter garden. I planted seeds, put out vegetable starts and then watched despondently as insects and other pests destroyed our little plants and sprouts.
Luckily, I read about a concept that has helped us grow successful winter gardens. This concept is the “Persephone period.” Elliot Coleman, author of many books on organic gardening, uses the term “Persephone period” or “Persephone days” to describe the time of year when the days have 10 or fewer hours of light. Since most plants need at least 10 hours of daylight for active growth, plant growth pretty much stops during the Persephone period and the garden shuts down.
Farmers have observed this phenomenon since ancient times and found ways to explain it. According to Greek mythology, Hades, the god of the underworld, abducted Persephone, the goddess of spring, and carried her down in his chariot to the underworld to be his wife. Persephone's mother, Demeter, the goddess of agriculture and the harvest, desperately appealed to Zeus to have her daughter returned. Zeus asked if Persephone had eaten anything in Hades. Persephone admitted she had eaten four pomegranate seeds. Zeus then decreed that Persephone had to stay in Hades for four months of every year. In ancient times, farmers believed that Demeter withheld fertility and plant growth during those months, until her daughter was returned to her.
When you understand this phenomenon, you can time the planting of your winter garden to ensure success. The first step is to calculate the Persephone period for your location by determining the date when the days become shorter than 10 hours. I did this for you.
The United States Naval Observatory has a “Duration of Daylight/Darkness Table” on its website (http://aa.usno.navy.mil/data/docs/Dur_OneYear.php/). The table shows hours of daylight for any location in the world and any date. For Napa, the first day this year with fewer than 10 hours of daylight will be Nov. 19, and the first day in 2019 with more than 10 hours of daylight will be Jan. 23. Between those two dates, our Napa Valley gardens will pretty much go dormant.
The secret to bountiful winter crops is to work around these dates. Since most seedlings need 60 to 90 days from planting to harvest, you can get a head start by planting fall and winter vegetable seedlings between mid-August and mid-September. The seedlings will take advantage of the daylight and warmth to reach maturity by mid-November. You may be able to impress your relatives with home-grown broccoli at Thanksgiving.
The mature crops that you don't harvest will stay fresh in the ground during the cool days of winter, almost as if they were in a refrigerator that you can access when you want. However, if you plant a little later — in early October, for example — your vegetable crops will not reach maturity this year. If they are close to maturity and large enough to resist pests, they can hang out in your garden over the winter and will spurt to maturity in February and March.
Another strategy is to plant seeds and starts just after the Persephone days end, in early February or March, when your garden is coming to life.
What you don't want to do is what I did previously: wait to plant until the Persephone period is underway. My thinking was, “It's a winter garden, so I should plant just before winter starts.” Made sense to me.
A winter garden can be deeply satisfying, providing nutritious and delicious produce such as chard, kale, mustard greens, cabbage, broccoli and Brussels sprouts. In the heat of August, winter seems far away, but now is the right time to get that winter garden going. Then watch next February for that spurt of plant growth as Persephone emerges from the underworld.
Workshop: UC Master Gardeners of Napa County will hold a workshop on “Houseplants for Health & Happiness” on Saturday, Sep. 8, from 9:30-11:30 a.m., at American Canyon Library, 300 Crawford Way, American Canyon. Brighten your home and bring the “outdoorphins” indoors with this practical hands-on workshop. Learn what houseplants need, from soil to light to water and fertilizer, and learn about some easy-care choices. Free starter plants will be available to take home.Online registration (credit card only); mail-in/walk-in registration (check only or drop off cash payment).
January is perfect for assessing your collection of saved seeds and making plans for the next round of gardening. If you enjoy starting your own vegetables and annual flowers, order seeds from catalogs now to get them before you need them, at the end of January or early February.
My least favorite winter task is watering, but in this dry winter, we must water to keep plants healthy. Vegetable gardens planted in the fall with winter greens, broccoli, onions and garlic will not thrive unless watered.
Water vegetables when the top one to two inches of soil have dried out, and moisten the soil to a depth of 8 to 12 inches. Perennial plants that grow and bloom in winter, which includes most native plants, will also need regular watering. Plants that go mostly dormant in winter, such as roses and fruit trees, still need some water to stay healthy. And frost-tender plants like citrus need to be kept well-hydrated to help them fend off frost damage.
In our climate, January is historically the coldest month. However, we can hope that we will not be repeating December’s run of below-freezing nights. Be sure to protect tender plants when frost threatens.
If the rains do come, expect an increase in weed growth. Control weeds while they are small, hoeing or pulling them out. Whenever possible, use mulches to control weeds and conserve soil moisture. If you use organic mulches, the material will break down over time and improve your soil.
Insect pests tend to be less of a problem in cold weather, but I noticed that aphids on my cauliflower and broccoli survived December’s frigid temperatures. Control these plant-sucking pests by spraying them off with water. Vegetables tolerate a few aphids, but these insects seem to multiply quickly if not addressed early.
Deciduous fruit trees should be dormant now, with all leaves gone. Now is the time to prune and shape them. First remove all broken, diseased or dead wood, then look at the tree from all sides and tackle pruning for shape and for fruit. Different types of fruit trees require different amounts of pruning, so consult a knowledgeable tree source if you do not know how much growth to remove.
Winter is also the time to spray fruit trees to control pests. Copper-based fungicides control fungal diseases such as peach leaf curl and powdery mildew. Spray on a dry, wind-free day and be sure to follow all precautions on the product label. Dormant oil sprays can help control insect pests such as scale and mites by smothering their eggs. Delay spraying until close to bud break in late winter or early spring.
Nurseries have a good supply of bare-root fruit and shade trees now. Bare-root trees are an economical way to add to your orchard or beautify your landscape. Keep the roots moist after purchase and plant as soon as possible. When preparing the planting hole, do not amend the native soil too much. Add no more than 25 percent compost to the soil that covers the roots to encourage the roots to dig deeper for nutrients. Plant the crown of the tree higher than the soil surface to allow for settling over time and to keep the crown from being inundated with moisture during rainy periods. Mulch well, keeping the mulch four to six inches away from the trunk to prevent crown rot.
Bare-root choices also include roses, ornamental vines, artichokes, strawberries and asparagus. As you would for bare-root trees, keep the crown of the plant at or above soil level when planting.
Any vegetables you planted in fall are probably growing slowly now, but check them often for maturity and harvest as ready. These might include lettuces, parsnips, beets, carrots, cabbages, broccoli and radishes. You can get an early start on the spring planting season by sowing seeds now for kale, parsley, radishes and spinach. These crops can be direct-sown outdoors, while the brassicas (broccoli, cabbage, cauliflower) should be started indoors for transplanting next month.
Enjoy the slower pace of January gardening. And if you have any influence with the weather gods, have them send us some rain.
Workshop: Join Napa County Master Gardeners for a workshop on “Rose Pruning” on Saturday, January 18, from 10 a.m. to noon, at the University of California Cooperative Extension (address below). January is the best time to prune your roses. Come learn pruning techniques from a certified Rosarian. Bring your rose questions. 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.
- Posted by: Yvonne Rasmussen
- Author: Susanne von Rosenberg
November 09, 2012 • By SUSANNE von ROSENBERG UC Master Gardener Napa County
Do you love onions and garlic? They’re easier to grow than you might think, and now is the time to plant them.
Onions and garlic are in the allium family, along with leeks and shallots. You can plant onions from now until January for harvest from May through July, depending on the variety.
Onions can be planted as seedlings from six-packs, transplants (available at local nurseries now or soon), or sets (baby onions). Sets are not recommended for California because the varieties are typically not adapted to our area, and they will bolt rather than form bulbs. Planting at the wrong time will have the same result.
Sweet onions are ideal for eating raw. American onions are better for cooking and will keep longer. Yellow onions typically store better than white strains of the same type, and red onions fall somewhere in the middle.
Leeks are also easily planted as seedlings. You can start onions and leeks from seed as well; consult Napa County Master Gardeners for information on the best time to start seeds, as timing depends on the variety.
Onions need a minimum number of daylight hours to start to form bulbs. Intermediate-day onions and certain strains of long-day onions do best in our area; local nurseries will carry appropriate varieties.
Onion and leek seedlings and transplants are hardy. You may not believe that these tiny plants will survive transplanting, but as long as you provide well-amended soil and adequate water, they will thrive. Keep them well watered and weeded initially, then maintain a regular watering schedule through the spring.
Onions do not need a lot of fertilizer. Feed lightly before planting and again in early spring. When the leaves become less firm, the bulb is mature, and you can taper off the water. The bulb is fully mature when the leaves fall over. (They will still be green.) The first time I saw these prostrate leaves, I thought some animal had trampled my onions.
Plant onions four inches apart; they need room to form bulbs. Alternatively, you can plant your seedlings or transplants closer together and thin them for use as green onions or spring (immature) onions. They are edible at all stages of growth.
Plant garlic now through February. Garlic is planted in the form of cloves. Be sure to buy certified disease-free seed stock from a nursery, catalog or certified grower to avoid spreading disease in your garden. Consider trying an unfamiliar variety. At the Heirloom Festival in Santa Rosa in September, one grower had more than 100 varieties of garlic on display. Soft-neck varieties keep better than hard-neck types, but hard neck varieties.are easier to peel. Grow soft-neck varieties if you want to braid your garlic.
Plant individual unpeeled garlic cloves, pointed end up, about one inch deep and four inches apart. Keep the soil moist but not soggy. Like onions, garlic plants are light feeders. In May or June the leaves will begin to turn yellow, even with adequate watering. Taper off the watering, and when the leaves are at least 60 percent brown, the garlic will be ready to harvest.
Plant the smallest cloves from your seed garlic closer together and harvest the leaves for green garlic. These leaves have a mild garlic flavor and will be ready long before your garlic bulbs have matured.
Garlic and onions must be dried if you plan to store them. Lift them from the ground with a garden fork. Wait until onions are completely dry in the ground before lifting them, then put them in a warm, dry place away from direct sun for a week or two. Garlic will take two to three weeks to dry enough to store. After your onions and garlic are sufficiently dry, bush off the dirt, trim the roots to one inch, and either braid the tops or cut off the tops about two inches above the bulb.
Napa County Master Gardeners (cenapa.ucdavis.edu) answer gardening questions Monday, Wednesday and Friday, 9 a.m. to noon, at the UC Cooperative Extension office, 1710 Soscol Ave., Suite 4, Napa, 253-4221.