In my Seattle garden, fallen leaves are drifting up around the edges of my vegetable beds like Technicolor waves lapping at the shore. Time to deploy the season extension.
This time of year, nature is getting ready to go dormant. Despite the occasional warm, sunny day, the weather pattern is changing. Shorter days (and longer nights), cooler temperatures, glorious rain, from drizzle to downpour, all signal the change in plants. Growth slows down. Cell walls begin to thicken in the plants, mirroring our defensive layers of fleece and wool.
Stave off the inevitable decline in your vegetable garden by covering those plants that are actively growing. The ones that will feed you salad this fall can be nursed along for a few more weeks if covered with a cloche or a cold frame.
The root crops that are going to be overwintered will be aided by a blanket of garden fleece, also known as floating row cover. Later this fall, you can pull off the FRC and cover those beets and carrots with a cloche, giving them more protection during our coldest time.
The kale, cabbage, broccoli and Brussels sprouts will benefit from a top-dressing of compost and straw mulch, between the rows and around the plants. This step can be taken for all the fall and winter veggie plants, but isn’t as necessary for those under a cloche or cold frame until the weather really reaches our daytime winter temperatures of 45 degrees. Still, I often do this now around my salad greens too, just since I’m out in the garden with the straw at hand. It’s often more pleasant to do it on a nice fall day than try to wait for a break in the winter rains that will take hold in November.
The main reason to do this season extension and mulching work is to protect our plants from the colder temperatures, pounding rains and desiccating wind.
A few weeks ago I put in a late batch of lettuces and raddichio into a long hoop-house cloche. With the unseasonably warm weather, I’ve been able to take that off for days at a time, and the veggies are nearing harvest. Now that rains and cooler weather are predicted, I’ve put it back on again.
Often at this time of year I’ll set up the cold frame over a bed with starts. It’s amazing to check the soil temperature inside the cold frame and in the bed next to it. Inside the bed, the temperature of the soil will be well above 60, while in the open garden the soil temperature is inching down toward the mid-50s. Capturing that warmer soil temp, keeping it from dropping so fast, is a key benefit to season extension.
Also this week we’ve had a couple of days of significant rain. At times, it’s come down pretty hard. A soft rain is great for watering the beds, and I open the season extension devices for a few hours in early afternoon if a light rain is coming down. The best situation is a nice soft rain for an hour or two, followed by a clearing and light breeze, so the plants dry out. Regular moisture on the leaves and stems of fall veggies can promote rot. If I can’t get the timing right to open the season extension during a light rain, I hand-water the beds as needed.
And I always keep the devices closed during a heavy rain. Over time, heavy rains will compact the soil, leach out the nutrients, and reduce those soil temps — all things I’m trying to avoid. Score another benefit for season extension.
The winds are also gusting this time of year. Combined with cooler temperatures and rain, the wind can be hard on tender vegetable crops. The worst effect is when it blows the top layer of
mulch away from the base of the plant, exposing the plant’s fine root system. Those roots will dry up, making it tough for the plant to survive, much less grow. Such stress will invite pests, and can trigger the plant’s desire to bolt and go to seed.
One final idea concerning season extension: what’s good for the plants is also good for the pests. In this sense: the pests love the warmer, drier location too. I’m picking a lot of slugs and snails out of my season extension devices right now, and off the plants. I need to be diligent about this, because they’re all drawn to the warm place with plentiful food. As the temperatures continue to drop they’ll become less of a problem, but right now, I need to pay attention if I want to keep those fall crops around for my autumn dinners, and not just be feeding the pests.
Fall in the maritime garden is a time to appreciate our weather. The change is usually not abrupt, giving me a chance to also adjust my own pace to the slowing rhythm of nature. But the decline into winter is inevitable, which is another lesson. At this pace, it seems more possible to stay in the moment, enjoying the color and patterns of those fall leaves as they naturally mulch the margins of my garden.