January 27, 2024: Recovering from the cold, raised beds (or not)

From Linda Gilkeson:

With the heavy snow gone you might be taking stock of the cold damage to garden vegetables this week. I was afraid to look under the tarps over some of my beds because it went down to -12oC at my house and that’s awfully low for veggies (some of you will have had even lower temperatures). I wasn’t worried about mulched carrots, beets, daikon, etc. as the cold didn’t last long enough to freeze the soil. So far my winter cauliflower and broccoli plants, leeks and Brussels sprouts, only seem to have a bit of leaf damage, but time will tell. Leaf damage doesn’t matter, but damage to stems allows rot to set in and that can be fatal.

Before you head out to undertake garden cleanup, remember that no matter how ruined some plants might look, probably more has survived than you think. Even if leaves of Swiss chards, spinach and other hardy greens have been turned to mush by sub-zero cold, do not remove the plants–the roots usually survive to grow new leaves for a spring crop. Leeks will have damaged outer layers but the hardiest varieties can be fine underneath. So don’t start clearing out the damaged veggies until March. By that time you will know what is re-growing and what isn’t. For now, if you covered any plants with opaque materials, remove the covers to let in light–we are back to temperatures high enough for some plants to be able grow. Leave thick mulches in place over beds of root crops, however, because we do not want those plants to warm enough to start growing. Because they are biennial plants, when they do start to grow again, they will use up sugars stored in their roots to grow a flower stalk, rapidly losing quality and flavour.

It is too early to tell now whether fig trees and buds of less hardy fruit trees have been damaged so that will have to wait until growth starts later on. Marginally hardy herbs, such as rosemary and French tarragon may have died if they were not well protected, but if bay laurel is killed to the ground by extreme cold, if it was well established (several years old), it should come back from the roots (as would established olive trees and some ornamentals, such as hardy fuchsia).

Other things to do right now (notes with links to other messages at Linda Gilkeson || West Coast Gardening || Gardening Tips because I’m doing 1 fingered, hunt-and-peck typing while recovering from a broken wrist and it is taking way too long to write this!)

-See January 20, 2023 for notes on pruning fruit trees now, while they are dormant, and on doing germination tests on seeds to check viability.

-See January 20, 2022 for more pruning notes, how to grow sweet potato starts from a grocery store tuber.

-See my pdf slide show “Grow Your Own Seedlings” at Linda Gilkeson - West Coast Gardening Now is the time to start seeds indoors, under grow lights, for celery and celeriac, because they are tiny plants that take a long time to grow to transplant size. Start onion and leek seeds by the end of February, but wait until March to start tomatoes and peppers, unless they are going to be planted in a greenhouse. For garden crops, there is usually no advantage to trying to start plants too early, as you can end up with stressed or over-hardened plants waiting for good weather.

The ABCs of Gardening: Garden Bed Design
Last month I promised some notes on garden design for new gardeners so I will begin with a review of the pros and cons of raised beds. For decades the go-to design for coastal gardens has been raised beds, usually with the some kind of edging or sides (boards, stones, bricks) to hold the soil in place at a level higher than the surrounding land or paths. The depth of soil would range from half a foot to 2 feet or more. The advantages of such raised beds are that the soil drains well and warms up more quickly in the spring than in low-lying beds. But with the warming climate and increasing need to conserve water every summer, raised beds are not as desirable as they once were: they require more irrigation over the summer and in heat waves the soil can get too warm for crops such as potatoes. There are still many advantages to having permanent beds, with pathways and growing beds always in the same place, but it doesn’t mean they have to be raised.

Before investing in building beds and buying soil to fill them, dig down to check the soil where you plan to garden. If there a foot or two of something that looks like soil, you probably don’t need to bring in more. It doesn’t matter how good the soil looks because you can enrich even the poorest soil sufficiently to grow vegetables by adding compost and other amendments (and for less than it would cost to build beds and truck in soil). Even if you buy “good” soil, it will also require the addition of amendments to be fertile enough for food crops.

There are still sites where raised beds are a good option: Where a garden has to be placed in a low-lying, wet area or where you are building beds on a slope or on sites without any soil at all, such as on a patio or other hard surface. And some people can’t reach low beds so need raised beds, several feet high, to be able to garden comfortably.

More next month, when I hope to be back to doing real typing again!


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.