From Linda Gilkeson:
Despite the nuisance of dealing with snow over the last week or two around the coast, the storms have been very good for vegetables in the garden (and for the shoots of garlic and spring flower bulbs that are up). Snow insulates plants, keeping them warmer than the air temperatures above, so the deeper the snow, the better the protection. When the snow melts, you might see broken or bent plants and cold damaged leaves, but don’t be tempted to clean up the garden: leave everything alone! Root crops should be fine if they were protected by a good mulch before the snow further insulated the beds. Chard, spinach, hardy lettuce plants can look pretty bad, especially if leaves were frozen to the ground, but they usually grow back from the roots to provide a much earlier and larger harvest than you could hope to achieve with spring seedlings. Kale can have all the leaves broken off by deep snow, yet after a few weeks of spring warmth, new leaves sprout all along the stems. Give cabbages time to thaw out before harvesting—it can take of week of above-freezing temperatures to thaw them out entirely. No matter how bashed and bedraggled winter broccoli and cauliflower plants look, as long as the stems have not actually been broken, most plants will put out a whole new batch of leaves, followed by heads between March and May.
Starting seeds: For everyone eager to start seeds early, there some vegetables that could be started by the end of this month IF you have the right conditions for growing seedlings indoors. It isn’t hard to ensure plants are warm, watered and have fertile soil, but sufficiently bright light is usually the most difficult environmental condition to provide. Even south-facing windowsills usually don’t provide the level of light needed by vegetables, unless they are in a sunroom or bay window. Most of us need a grow-light setup to be able to produce early seedlings that are healthy, without weak, elongated stems caused by reaching toward the light. Along with other seed starting info, you can see examples of grow light setups, including high-intensity fluorescents and LED tubes, in the pdf of the talk on my web site: “Grow Your Own Seedlings” http://www.lindagilkeson.ca/presentations.html
Other tips for starting seedlings: Vegetable seeds germinate best under very warm conditions, 22-30oC [72-85oF], so start them on a seedling heat mat or in the warmest place in the house. Unlike some seeds, light is not needed for vegetable seeds during germination, but once the first tiny green tips appear above the soil, move them to cooler conditions 18-20oC [64-68oF] with 16 hours per day of bright light. If you can’t supply bright enough light, wait until April to start seeds indoors and once they germinate, move seedlings outdoors to a cold frame, unheated greenhouse or tunnel during the day. Bring them indoors every evening until overnight temperatures stay above 12oC/54oF. Although it takes daily care to put plants out and take them in and to ensure cold frames are opened to prevent overheating on sunny days, you can raise good quality starts under this regime.
This month is a good time to start celery and celeriac seeds as they are slow to germinate and the tiny plants take longer than other vegetables to reach transplant size. Onion and leek seeds can be sown indoors in late February or early March. But don’t be in a hurry with anything else: plants sown too early often end up stressed by being held in pots too long or damaged by being planted out too early, making them vulnerable to late frosts and cutworms. Early plantings of warmth loving plants, such as squash and tomatoes, can also suffer nutrient deficiencies under cool conditions when temperatures are too low for their cells to function properly. And there is always the problem with biennial vegetables, such as chard, onions, leeks, celery, becoming vernalized by a cold week or two in late spring after they have been growing outdoors for awhile. A late period of chilly weather can fool these plants into sending up flower stalks in July of their first season instead of waiting until their second summer to flower as biennials should. This is a common problem for coastal gardeners because we are the only gardeners in the country that try to plant vegetables outdoors in March or April. People aren’t always aware that a lot of common vegetables are biennials so it is quite puzzling when the plants make flower stalks instead of leaves or bulbs as expected. The lesson here is that gardeners who work hardest on starting plants early are the ones most likely to run into the vernalization problem….
Considering a dormant spray? If you have fruit trees you might have been told to spray dormant oil and lime sulphur in mid-winter while the leaves are off the trees. Before you do that, however, consider why you are spraying. No pesticide should be used routinely: not only is it pointless and a waste of money, but it needlessly harms beneficial mites, insects and other organisms that also overwinter on trees. Before considering whether a dormant spray is necessary, you need to know if any pests or pathogens are present for which such sprays actually work. If so, then you need to decide whether the problem is serious enough to justify spraying, considering the damage sprays do to non-target organisms. Unfortunately, dormant oil sprays are often used in an attempt to control problems for which dormant spray do NOT work, such as tent caterpillars or codling moths. Dormant oil sprays do work on overwintering aphid eggs, winter moth eggs, scale insects, pear and cherry sawflies (photos of most of these are posted on my website). With the general exception of scale insects, however, there are other more effective, non-pesticidal, controls that can be used instead.
As for lime sulphur dormant sprays, they do NOT work on apple scab or pear trellis rust because these fungi are not on trees in the winter. They can help control pear scab because some spores of this fungus overwinter on trees, but other methods are also required to control the rest of the spores on fallen leaves. Lime sulphur sprays can reduce damage from peach leaf curl, pearleaf blister mites and apple rust mites, but NOT if applied in mid-winter when dormant sprays are traditionally recommended. To be effective for those problems, lime sulphur is applied when 90% of leaves have dropped in the fall (November) and again when leaf buds swell (February/March). Despite noting this improved timing, it doesn’t mean I recommend sprays. The only dormant spray I used to use in over 30 years of growing fruit trees was lime sulphur on pear trees to control pearleaf blister mites, which tends to show up at 5 or 6-year intervals. Over the years, however, I learned that if I did not spray, the blister mites disappeared the next summer anyway, probably because native predatory mites keep them in check. Anyway, who wants to go to the trouble of spraying if you don’t need to, especially with smelly sulphur!
Recycling corner: Rather than rewriting information in previous newsletters, here are some “greatest hits” from the archive of newsletters on my website: Linda Gilkeson || West Coast Gardening || Gardening Tips
-If you want to grow sweet potatoes (AKA “yams”), ginger root or turmeric plants this summer, now is the time to sprout a root from the grocery store. These 3 plants thrive in the warmest conditions so are ideal summer crops for greenhouses or tunnels. For how to get started, see notes from the February 27, 2024 newsletter.
-And here is a section with tips on keeping costs as low as possible for a food garden: Gardening on the Cheap in the Feb. 20, 2023 newsletter. This is more important than ever as we feel the price squeeze from local, international and global events. The beauty of a home garden is that it can turn waste into food!
Republished with permission from Linda Gilkeson’s Gardening Tips. See Linda’s website to sign up for her newsletter, purchase books, access free presentations and identify pests and diseases which may affect West Coast gardens.