Spring certainly went sproing into nearly summer-like weather this week! Given how long it took the snow to melt from my yard I thought the soil would stay cold longer than usual, meaning no rush to dig up overwintered root crops. At the rate the soil is now warming, however, carrots, beets and other roots should be dug up by the end of March/early April as usual. If left in the garden, they start to grow, using up the sugars stored in their roots to produce a flower stalk. The roots lose flavour and crispness and grow lots of strange little side roots.
Don’t be too hasty in clearing out the rest of the garden right now, though. Really battered plants can still grow a new crop and even Brussels sprouts stalks that have already been picked and have no leaves left usually grow tasty new shoots all along the stem. After 6 weeks under heavy snow my lettuce was flatter than I have ever see it, but has since popped up and is growing fine. Ditto for chard, spinach, kale, cauliflower and broccoli that looked awfully crushed when the snows first receded.
Frost Free Dates? This week’s weather emphasized the futility of trying to plant based on average last frost free date. With our varied geography, frost patterns can be quite different from one garden to the next depending on elevation and how close you are to large bodies of water. At higher elevations this week the nights have stayed very warm for the time of year due to temperature inversions, while valley gardens a short distance away have continued to have frost at night. Since average last frost dates are calculated from long term weather records, which are mostly recorded at airports, they don’t mean much unless you live at the airport. Past records don’t mean much now, anyway, with weather becoming increasingly variable due to the changing climate. What was the coldest February on record in our region was followed just a few weeks later with record setting high temperatures….so no matter when you plant this spring, be prepared to cover small plants with plastic, cloches or floating row covers if it gets cold and be ready to shade them if it gets hot.
Seedlings: If you are starting your own seedlings under grow lights or in a greenhouse, try to set the small plants outdoors in the sun for at least a few hours on these warm days. They will grow better and with early exposure to sunlight will be used to the sun and won’t get sunburned when they are transplanted. Of course, you still have to bring them inside when it cools off in the afternoon as it is much too cold for them at night right now. This unusually sunny weather for March means it can get really hot in greenhouses, tunnels, cold frames and cloches, so keep on top of opening vents or removing covers as needed.
Climbing cutworms: These are big and fat right now (nearly the size of my little finger) and will actively chomp pretty much anything in the garden for another month or so until they pupate. They are one of the reasons I don’t try to set things out too early (that, and the fact that there is already so much growing, there is really no rush…). For what the cutworms and their damage look like, see. To catch them in the act, go out after dark with a flashlight and look for them on leaves (they hide in the soil during the day).
What to do now: If you just have to do something in the garden, rake back mulches from beds you will be planting first to let the soil warm up and dry out. Sprinkle a little of the iron phosphate slug bait over the soil surface to control slugs before your tender seedlings are set out. Start pea seeds indoors in trays of vermiculite or perlite and grow them to several inches in height; by that time the soil should be well warmed up and there will be fewer cutworms around. Arrange seed potatoes along a sunny windowsill for a few weeks to develop strong dark green sprouts before planting them out (this is called ‘chitting’). If your garden is really warm and you want to plant something, go for annuals, such as lettuce, spinach, Chinese cabbage and other annual greens in the cabbage/mustard family. Planting out biennial vegetables this early (chard, kale, onions, leeks, cabbage) can result in a crop failure if there is a cold chill later in the spring that causes them to bolt prematurely (send up flower stalks) in mid-summer.
Upcoming event for Salt Springers: Thursday, April 11, 7:00 pm. I will be giving a public talk at Meaden Hall on the global insect crisis, entitled “Where Have All the Insects Gone?”. Sponsored by the SSI Conservancy, Salt Spring Garden Club and the Farmlands Trust.