Floating row cover, weighed down and made semi-transparent by water, is all that stands between fine young brassica greens and the scourge of the flea beetle. The cover is placed right after seeding, weighed down by rocks every 12.5′ feet, briefly rolled back for weeding, and progressively loosened as the greens grow—we use 14′ wide sheets on 10′ wide beds. This medium-weight cover has worked as a good all-round solution, offering a few degrees of frost protection, and more durable than a lighter, insect-only weight, which would allow better light transmission (this medium weight one is 85%) and better air circulation, but also be more likely to tear.
The covers are off and it’s all shades of green! That’s about three months, left to their own devices, living through freezing nights, often around -20°C (-4°F), and a low of -32°C (-25.6°F), under a couple of layers of medium-weight row cover, which means, little light (with the plastic added in, somewhere around 50% of already weak winter sun). Inside, at ground level outside the row cover, the lowest it got on the coldest night was an amazingly not-so-chilly-at-all -13°C (8.6°F). As a simple survival test…excellent!
There’s official calendar Spring, and then there’s spring in the field, that ignores exact dates and goes by the weather, marking winter as over whenever the freezing temperatures end. If today’s two-week weather forecast is anything to go by—it is, in this case, when being off by ±5-10°C (14-23°F) either way isn’t a big concern—market garden spring starts now. For the moment, I’m mainly concerned about overnight lows in the unheated greenhouse, and whether row cover is necessary. If it stays above -15-20°C, my safe-with-no-cover cutoff, it should be fine to pull back the covers and let the sun shine in (prepared, of course, to put it right back if there’s a sudden severe dip, which we hope doesn’t happen). Nothing complicated, just a little of the gambling that’s called working with the seasons!
Not your typical postcard sunset, and it’s kinda chilly, damp and mucky in here, even as the temperature outside slides down to an overnight -15°C (5°F). But it’s all about the greens, tucked under a couple of layers of row cover, maybe not exactly cozy with only ground heat to keep them warm—who knows how they’re really feeling—still, well-set to survive another sub-zero night. With that in mind, sundown through 6 mil plastic is a cheery-enough sight to see!
Electric fence wire work, snipping 6-foot pieces of 9-gauge wire for hoops to hold up floating row cover in the greenhouse. Hopefully this wire is stiff enough to do the job, supporting up to three layers of row cover, heavy with moisture from humidity and being dripped on by water condensed on the inside of the hoophouse plastic, or weighed down by ice, when the soaked cover freezes at night. This test batch of about 180′ came coiled, in a circle about 2½’ in diameter, and the built in curve is perfect for stretching slightly to span about 4′ of bed. So, no bending required, it’s all about the snipping!
Exactly where it was delivered last fall, the steel for the new hoophouse is kinda in the way, so we’re working around it (it doesn’t look like much in the pic, but it will expand into 30’x108’x16’H of plastic-covered year-round field protection). Beds of brassica greens are already in and protected by row cover from flea beetle attack. Lisa preps beds for more. Spring direct seeding proceeds…
Not the happiest campers after three days and nights of frost protection, peppers and eggplant have one day and two nights more under row cover, if the forecast is to be believed. But the 15-day forecast a week ago was for no more cold nights, so…who knows! We’ve had about a week of frost warning nights so far since the second week of May, which I don’t think I’ve seen before. Normally, the covers would come off during the day, but with everything else to do now, and the kinda elaborate weighting-down-with-rocks setup, it’s simpler to leave it in place till the end…