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.
Two weeks ago I put in a late batch of lettuces and bok choi, and set up the cold frame over the bed. Yesterday I checked the soil temperature inside the cold frame and in the bed next to it. Inside the bed, the temperature of the soil is still 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.
Recently, a gardener asked our Master Gardener clinic why their broccoli didn’t flower. That question comes up regularly, and I’ve studied it in my own garden, with my own successes and failures.
Someone also asked me the other day if it was too late to plant winter brassicas.
Finally, I want to share a tip about what to do with your Brussels sprouts plants this time of year.
So I’ll tackle three brassica topics in this post. Here we go.
Why broccoli didn’t flower
If your spring- or summer-planted broccoli didn’t set its flower buds (the part we eat), it could be due to planting at the wrong time, uneven watering, fertilization issues, planting bad starts or bad treatment of seeds or seedlings.
For summer harvest broccoli, timing is tricky, because you want to plant earlier in spring so you get the crop before the summer heat, but if you plant too early, the broccoli won’t get a robust start. If you plant too late, the heat stresses it. I’ve had best success when planting starts in early to mid-May (or doing a succession of plantings through May). That means you’ll be cutting heads in mid-July and into August.
In my experience, they like a lot of compost, which also helps to regulate moisture. So I put them in a well-composted bed, and add a top-dressing a few weeks after planting. I’ll feed once with a balanced complete organic fertilizer, about a month after planting.
Fertilizing with a lot of nitrogen as they’re trying to form heads could prevent the plant from flowering, and probably just produce more leaves.
For overwintering broccoli like purple sprouting (my favorite), I start the seeds in late May/early June, then plant them out in August. Also tricky to keep them consistently watered during that seedling stage. I top-dress with compost in mid-September, then lay a bed of straw mulch over the soil for the winter. They’ll send up a small central head by early March, followed by sprouts.
I don’t grow fall-harvest broccoli often, but I believe that it’s on the same planting and transplanting schedule as sprouting broccoli, but will produce heads in late September. I found the harvest to be small, so now I just concentrate on the sprouting ones.
Brussels sprouts ‘tip’
On to the Brussels sprouts. If you have winter harvest sprouts in the garden now, you’ve probably noticed small sprouts forming along the leaf axils. Also, you’ll probably see a denser set of leaves forming like at the top of the plant. If you cut off that growing tip, the sprouts should develop faster and more robustly. That’s because the plant is now putting all its energy into the sprouts rather than the new leaves.
Here are photos showing this cut on one of my plants:
Planting brassicas now?
One final note about whether you could be planting brassicas now. The answer is, not really.Most brassicas should be planted in May and June, and transplanted in August, or at the latest in early September.
However! If you can find healthy kale plants still in the nurseries, you could put them in, but I would not expect much production from them over the fall and winter.
If you’re focused on growing food year round, you might almost forget the idea of putting the garden to bed. But it is still a good concept, for a couple of reasons:
1. You probably won’t have the time or energy or desire to keep your entire garden growing year round.
2. Soil needs to rest periodically, so that nutrient levels do not get entirely depleted.
As the summer vegetable garden fades, use cover crops and mulch to protect the soil over winter.
These will help build soil as well as keep the soil well-covered so that winter rains or winds don’t damage it. They also provide a habitat for soil critters.
There are various types (straw, leaves, compost, sheet-mulch layers), and they all will help keep the soil from getting compacted by rain or dried out by wind, and provide a habitat for beneficial soil organisms. As they break down, they add carbon to the soil as well. Caution: You don’t want to provide a habitat for rats or other vermin. If you see signs of that, remove the mulch.
These are available from coffee roasting companies and some nurseries or hardware stores. Laying these on the soil helps protect it from pounding rains, and keeps the soil a little warmer for the soil-dwelling critters.
Two simple growing steps
If you want to have something growing in the beds that won’t require any work, including harvest, here are two simple things to do:
* Grow some garlic! Plant it in late fall and harvest it mid-summer. Use a light mulch like straw or leaves over the bed after planting.
* Let the flowers be. If wildflowers have grown in around your veggies, don’t remove them when pulling the vegetable plants out. Some will reseed and even sprout this fall, and others will sit dormant until spring. Scatter a light compost mulch over the bed to encourage them.
More ideas in class
Want to delve more deeply into ideas about putting some of your garden to bed? Join me this Saturday, Sept. 20 at 10 a.m. at City People’s Garden Store in Seattle’s Madison Valley, for our final class in the Edible Year series, “Preparing Your Edible Garden for Winter” will offer more ideas and techniques to gently ease your garden into another season.
Your favorite nursery might have a large seed rack with notations like this one:
They also should have a number of starts of excellent brassicas, greens, leeks and other fall and winter vegetables.
Does that clue you in? Now is the perfect time to get many fall and winter vegetables in the ground.
I’ve just transplanted my Roodnerf Brussels sprouts starts, and I purchased a six-pack of Rubine sprouts for a little variety. I also have rapini — broccoli raab — going in, as well as kohlrabi and two types of kale. All those are starts that are 4-6 inches tall and have just a handful of leaves.
Right now you can start beets from seed, direct-sown in the soil. A few weeks ago I planted three types of beets, just a half-row of each. Then last weekend I filled out the row, while thinning the baby beets to wider spacing. I also added a handful of radishes, planted on a grid 4 inches apart.
Soon it will be time to plant overwintering carrots. My favorite variety is Merida, which you can see from the picture is available in stores. I want the carrots to get a few sets of leaves before winter, and then they’ll go into stasis surrounded by a nice mulch. In spring, they’ll shoot up and give me a very early, sweet and crisp harvest.
Brassicas, of course, are the star of our winter garden, and transplants of many types and varieties can be set out now. Sprouting broccoli, cabbage, cauliflower and collards can go in.
Many greens can be planted now. How about a nice big batch of spinach? Make sure to amend the bed with lots of compost when seeding that in. Also sow Asian and European greens in succession for the next month to get a continual salad harvest up to Thanksgiving.
How do you save seed from a favorite tomato? Will bean seeds dry fully in the yard? How do you keep birds from gobbling all your flower seeds?
Those practical issues, along with a bit of science and philosophy behind saving seeds, will be the topic of my talk this Saturday at City People’s Garden Store in south-central Seattle.
“Saving Seeds of Your Favorite Edibles” is the sixth of seven classes in our Edible Year series. It’s 10-11 a.m. Please pre-register with the nursery.
On Sunday I’ll head the other direction, both literally and figuratively. Going north to Swansons Nursery, I’ll give a slide show and presentation on what to grow now.
In “Edibles for Fall and Winter” I’ll detail what crops you can get started now from seed, what to look for in the nursery, and when to plant them for fall and winter harvests. We’ll also discuss “overwintering” crops that you start now and plan to eat next spring. That talk, also free, begins at 11 a.m.
Contest alert: $1,000 Available
Do you work with a community garden that could use some new supplies, or has big plans for next spring but could use plants? Then you should apply for the City People’s Garden Store Urban Garden Contest! The chosen entry will get a $1,000 gift card that can be used at the nursery over the next year. Deadline is Aug. 31, so there’s still time to apply.