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.
My many fall and winter Brassicas are sizing up nicely, but the ones not tented with floating row cover are showing a little chewing and some curling leaves. The culprits are cabbage butterfly larvae, snails and aphids.
Predator insects are still plentiful in the fall, but these pests can stunt the growth of young plants at a time when they need to be powering into winter with a strong growth spurt. To ensure robust, healthy plants, I am going hunting.
The larvae of the cabbage white butterfly or imported cabbageworm (Pieris rapae), often called the cabbage moth, are my first prey. Mostly what I’m finding right now are the slender green worms. They can hide — almost — by stretching out for an afternoon nap in the stem of a young leaf. They are further protected from my predatory grasp by secluding themselves inside the youngest leaves, the curled and furled ones sprouting from the plant’s center.
Carefully, so as not to snap the tender growth shoots, I unfurl the rolled green shoots and lightly scoop through the inside with a fingertip.
Then I bend back the plant’s slightly larger leaves and unfold them one at a time, checking the base of the stem for the pale green body. Finally, I flip the leaf over between fingers and eye the back, in case one of them is on the move. (I look also for the elongated eggs, white or yellowish, on the undersides of the leaves. Those get squished too.)
Just the act of inspecting the plant can cause these critters to fall to the soil below, where they would pretty promptly inch under a leave and climb back on the plant, so I scan the soil surface too.
These pests can go through 3 to 5 life cycles per year, and can be in the garden from April through October. The jerky white butterflies with black wing dots flit around from plant to plant. Amazingly, they mate in the air. Their eggs take 4 to 8 days to hatch, and the green worm larvae lives for 3 weeks before pupating, where they cocoon themselves for a couple more weeks before emerging as a butterfly and beginning again.
I think — I hope — they’re on the year’s last life cycle.
Green and grey aphids are a regular presence in my garden, and I’m finding small colonies on the broccoli, Brussels sprouts and kale. They take up residence on a stem or in the folded end of a leaf, and as they suck the juices out of the tender leave edge, it curls, providing them a cozy home.
Ones hiding in the leaves are fairly easy to spot, as the leaves also turn slightly purple on the edges when attacked in this way.
Again, my preferred method is to gently curl back the edges of the leaf and expose them. As they are also soft-bodied insects, they also will get quickly smooshed in between a thumb and forefinger. There is a little inevitable damage to the leaf area that was their home, but it’s much preferable to letting them form a stronghold there and begin to feed farther down the leaf and fill the stem, as they would like to do.
When the aphids have colonized the base of a set of leaves, or the stem of a plant, a hard spray of water from the hose, straight down into the center of the plant, will wash them all off and drown a lot of them. Most of the rest are too weak to climb back onto the plant. I find that I need to return and do this again in 3 days to make sure I’ve gotten them all.
I used to see a lot more slugs, but the garden ecosystem has evolved to be more hospitable to snails. They are moving from my dying summer plants into my winter beds. It’s happening at a snail’s pace, but that’s fast enough for me to put on my camo gear and start stalking them.
These guys are a lot more visible than the others, as their brown shells stand out on a green leaf, even at a smaller size. They especially come out on a cool or rainy day, or right after dark.
Sometimes I’ll find their gelatinous, round white eggs in a cluster on the edge of a bed, usually near a rockery or some other good hiding place.
But the hatched snails, or slugs, are most often found on the underside of the leaves, and they are quickly transferred to the underside of my foot on the path. Score another one (or ten) for the big guy.
These creatures are fascinating, and are all part of nature’s plan. And I don’t mind sharing a bit of my food with them. But this time of year, when the tastiest things on their menu are the young plants that will comprise my winter dinners, I am in a less permissible mood. Fall is for hunting.
The spinach leaf miner has been a scourge in my garden this summer. While I’ve been snipping and destroying affected leaves, which is the best tactic once your plants are under attack, I’ve also been conducting an experiment to see if I can avoid the pest.
Leaf miners attack the leaves of spinach, beet and Swiss chard, and their presence can be devastating and unsightly. At our Master Gardener booth at the Ballard Farmers Market this summer, we have had more questions about leaf miner damage than any other problem. Clearly, this is a pest that has flourished in northwest Seattle this summer.
Here’s what the leaf miner (Pegomya hyoscyami) can do to a leaf:
That photo is a bit dramatic, because of a recent rain that rotted the damaged parts of the leaf.
Here’s perhaps a more typical view of the damage:
What you see is the result of the pest larvae burrowing into
the leaf and mining their way through the cells. They arrive at the plant via a small fly, which lays its eggs on the underside of the leaf:
One way to thwart this pest is to regularly search for those eggs and destroy them when you see them. But if you love beets and chard like I do and have a lot of plants, this method is difficult. So I tried another way.
This summer I started a batch of Rainbow chard in a large pot and covered the pot completely with floating row cover, the spun-bonded polyester fabric that is so useful to us cool-season gardeners.
As the plants grew, I had to prop up the material to get a sprayer for my watering system into the pot. I used interlocking wire flower stakes to hold it up. Here’s what it looks like:
And here it is with the floating row cover removed:
Although the chard is planted rather thickly and hasn’t achieved its full size yet (I’m thinning as I eat it), I found that I could completely avoid the leaf miner with the floating row cover. I have been monitoring the pot regularly and have seen no damage. Just six feet away in the adjoining bed, I had such heavy damage to a row of baby beets that I had to harvest them prematurely.
As I continue my fall planting of beets and chard, I will again cover the plants with floating row cover. I’ll also plant the new crop far away from the area where the plants got hit the hardest. Crop rotation and floating row cover are tried-and-true non-toxic ways to reduce pest damage in the vegetable garden.
Purple Sprouting broccoli (my favorite winter vegetable) takes an incredibly long time to mature. A reader comment prompted me to think again about this amazing biennial plant.
Annual broccoli planted in spring or summer can produce in as little as 65 days, but Purple Sprouting needs to get started during the heat of the summer and size up a bit before fall. If started by mid-July, you should have plants that are knee-high before the days get so short and cool that growth grinds to a halt. But in late winter they’ll take off again and start pumping out the purple in very early spring (February) on plants that can be waist-high.
First you’ll get a small central head, and after you cut that, numerous shoots will appear from the axillary buds at the base of the leaves. Cut when 6 to 10 inches long and look for more to appear. I can often get a half-dozen meals out of one plant, and the harvest time can stretch over three months.
Compared to summer or fall broccoli, Purple Sprouting is an all-star producer, and well worth the wait.
Crops seeded now, during the warmest, driest part of the year, need extra-close attention.
A note on the cabbage butterfly:
Actually called the imported cabbage worm (Pieris rapae), this is the common white butterfly with black wing dots that jerkily careens around our gardens. It is looking for plants of the Brassica genus.
This pest lays its eggs (tiny white or yellow groups of them) on the underside of the leaves. When they hatch, the larvae (a tiny green worm) feed on the leaves. Their feeding can destroy a young plant,
so I keep the floating row cover on until the plant is large enough to defend itself.
Another nice thing about winter gardening: this pest is much less prevalent. I rarely see them after about early October.
My wife and a bunch of neighbors saw these unwanted visitors parading through our city block yesterday:
Yes, dear, those are deer. Blacktail deer, according to a hunter friend from the country.
Which is where these two must have come from, unless my neighbors Craig and Karen put on awfully good Halloween costumes.
We live on a steep street with the houses pretty tightly packed. A downhill neighbor saw these guys in another yard before they ambled through her yard, then the next, then our yard (more on that in a minute), and then went up the street.
At that point, Susie was driving home and saw them in the middle of the street. She ran inside and got the camera. She snapped their pictures in two yards up the block before they calmly navigated the steps out of the yard at the top of the block and headed south.
I sent the pictures to the PhinneyWood blog, which got a lot
of comments and Facebook links from posting them.
I guess there’s so much food in these city yards that our country visitors can just snack a little here and there and have a progressive dinner as they amble through the neighborhoods.
We’re lucky. I have many friends in suburban and rural homes whose yards are stripped clean of flowers, vegetables, and any desirable vegetation from the ground up to the height of a deer’s head. The only way to grow a vegetable garden in deer country is with a big, sturdy fence.
Later yesterday there were further sightings of these two, but as far as I know, no roadkill reported.
I won’t say that I was happy to see this wildlife clearly out of their natural habitat — and definitely in a dangerous environment — but it was a good reminder that we’re never
too far from nature, in its many forms.