It’s time for edible gardening, even in the library.
As part of the Seattle Public Library’s Edible Garden series, I’ll be giving talks on growing cool. The first one is this Sunday in West Seattle.
I’ll talk about my favorite cool-season vegetables, and what soil and climate conditions they like. I’ll show lots of pictures, answer questions and even share some veggie seeds.
You also will learn about the many ways you can get your edibles growing better by using season extension techniques, which are the secret tools of the year-round vegetable grower.
Make a date and join me:
April 20, 2 p.m. — Seattle Public Library, West Seattle branch.
May 4, 2 p.m. — Seattle Public Library, Montlake branch.
May 20, 6 p.m. – Seattle Public Library, Greenwood branch.
These library events are free and open to everyone. No pre-registration is required.
Want to get planting earlier, warm the soil, protect starts as they harden off? You need a cloche or a cold frame. I have just the thing: an easy tunnel cold frame that you can build without much cost or skill.
First, go window shopping. Not peeking in windows of downtown stores — shopping for windows at building salvage places. A great one in Seattle is Second Use, where I’ll be leading a workshop this Sunday on this very topic.
Second Use, the ReStore and similar shops in many cities are great places to find inexpensive materials for garden building projects. They reclaim old window sashes and doors when homeowners are doing remodeling. They also have random collections of building materials, like wood or stone for raised beds, pipe for cloches, mesh for trellises and even old bathroom fixtures you could plant in, if you want. For the sake of your neighbors, please try to resist.
So here are the basics of a simple, lean-to window tunnel.
Find two window sashes of the same size.
Aluminum-framed ones are great, because they’re lightweight, and won’t rust in wet weather and soil contact. But they’re hard to find. Wood window sashes are great, with a couple of caveats. Find ones with solid putty that holds the glass securely. Look for recent ones that don’t have peeling paint. Older windows, before 1973, will likely have lead paint, and that can flake off into your garden, and is a hazard for the environment, you, your kids and your pets.
I’ve found some glass-fronted cabinet doors that work great. It’s less likely that lead paint was used on interior projects, and these are varnished on one side. They’re not real large, but big enough to grow a three-foot row of something, or to easily cover one flat of seedlings.
Carefully drill two small holes into the edges of one side of the frame. Into those, screw round eye hooks. These should match on each window, so when you lean them together in an A-frame shape, the eye hooks almost touch.
Set up the windows on a garden bed, then run a heavy-gauge wire through the eye hooks and twist it up to hold the windows in place. This will prevent them from collapsing into the bed and crushing your plants.
On each end, pile straw to cover the triangular-shaped hole. This will provide enough protection from wind, and will help hold in the warmth that will have been gained during the day. You could also lean full bags of mulch against each end, or find some other way to block those openings.
For a warmer solution, cut a piece of 6-mil plastic to fit each end, stretch it tight and staple it on. Or even cut triangular plywood ends and screw them into place. Adding something permanently to the end makes it more difficult to move the cold frame or take it apart for storage.
This simple building project will raise the soil temperature under the windows by 5 degrees or more, helping you plant earlier and provide a warmer environment for seedlings. Just don’t forget to water, and look at it daily to make sure it’s working properly.
Want to see more ideas and shop for salvaged products? Come to my talk at Second Use on Sunday, April 6 at noon. Better yet, come early and shop the plant sale that is accompanying the event. I’ll show slides of many ideas, give a couple of demos, and then we’ll walk the store to find the hidden treasures.
The last of the Brussels sprouts have finally come out of the garden, and they held pretty well until the intermittent warm days we’ve had in the last couple of weeks. Then they started to really, well, sprout. The remaining loose sprouts are shooting up into mini flower stems.
Here’s the last good stalk, showing its interesting spring habit.
I cut away the leaves along the sprouts, but left this one eruption for show-and-tell. If it sat in the garden much longer, all of the sprouts would look like this. In fact, here’s another plant that didn’t sprout-up properly, so I’m just letting it go to flower.
The main stalk of the plant bends left, and toward the bottom, a number of sprouts have opened up and shot out at a right angle. A few of the flower buds are about to open.
I could still be eating it at this stage. We often eat the Brussels sprouts leaves if the plant doesn’t produce sprouts but just gets very vegetative. They’re a quicker stir-fry and still have that tangy, smoky flavor unique to this cool-season crucifer, Brassica oleracea, Gemmifera group. You can also eat the flowers, which provide a light sprout flavor when tossed into the dish briefly at the end of cooking.
I’m often asked about planting Brussels sprouts, as it seems that many times they do not properly produce sprouts. I’ve certainly had my share of failures (see above). I think it’s a combination of timing, soil fertility and weather. Well, isn’t everything?
Open-pollinated (OP) Brussels sprouts range 180 to 250 days to harvest. That’s 6 to 8 months, so you really need to plan ahead. There are F1 hybrids that have been bred to mature much faster, as quickly as
75 days or so. I like to grow the OP varieties and harvest in winter, because I love the way brassicas get sweeter after they’re hit by frost.
For such long-season plants, I always start them in flats and then plant them out into the garden. I’ve found that if I get the transplants into the ground by mid-June, I should have sprouts for the holiday feasts. If I don’t get them in until mid- to end of July, I’ll be eating them in February and March. It’s a good idea to grow two varieties with different maturity dates, or practice succession sowing, so you will have a longer harvest. (The F1 hybrids are also planted in May and June, for harvest in late summer.)
The seedlings will need 5-6 weeks to transplanting, so that means doing the first sowing in pots by May 1.
I usually apply one feeding of liquid organic fertilizer to my starts, when they’ve gotten a few sets of leaves and are maybe 2-3 inches tall. When I plant them in the garden, I work in a spadeful of worm bin compost or a dusting of complete organic fertilizer (COF). Along with the N-P-K, they need the secondary nutrient sulfur and the trace mineral boron, both of which are present in organic fertilizer.
I do not fertilize much once the plants are in the ground. In my experience, they seem to grow better in a soil that is a bit lower in pH than the neutral 6.5, so I don’t plant them in freshly limed soil, because lime brings the pH back up.
Also, I am betting that, once the plants are established, the active soil food web will take over and deliver enough fertility throughout the root zone of my plants. For overwintering plants like Brussels sprouts, they need to put on most of their growth by late fall, say by November 1, because the cooler soil and shorter days trigger much lower activity in the soil food web, and fertilizers will not be as available or taken up by the plants.
My final step in proper plant feeding is to get a soil test done every 2-3 years to see how I’m doing. If you’re growing crops in your vegetable beds year-round, you need to pay much more attention to soil fertility.
And if you’re growing organically (and I hope you are), you also need to pay attention to potential diseases. Fungal problems like club root and bacterial diseases like black rot can affect brassicas, and the best defense is good garden sanitation and crop rotation.
The transplanted Brussels sprouts will be still young plants, just starting to get some size, by the time our warmest summer weather hits in August, so you might be tempted to plant them in partial shade. I advise against that. I’ve had best production from the plants in the most sunny spots. The challenge is keeping them well-watered during their crucial late-summer growing season.
They will benefit from a bed with lots of compost, and a top-dressing of mulch on the soil during that warmest time. That will help the soil retain water better, which means less stress on the plants. (Another stressor at that time of year is aphids, which love to swarm along the juicy stem and thick leaves. Douse the plants with a hard spray of water whenever you see aphids to keep them at bay.)
Fall and winter treatment
In the fall, a predictable cooling weather pattern provides the best situation for overwintering plants.
I apply a loose mulch of straw around the base of the plants in October, to keep the soil slightly warmer and prevent the roots from becoming exposed and desiccated by winter winds. If an unpredictable early freeze is forecast, I might throw a blanket of floating row cover over my brassicas to protect them a bit more.Brussels sprouts nutrition
But by December, the plants should have acclimated to winter, and don’t need covering. In fact, covering can be detrimental, as it could provide a cozy spot for pests like slugs and snails to take up residence.
Once the plants have reached full growth, you can nip off the tip of the plant, so it will send more energy into sprout production. I often forget to do this, and still get sprouts. Often, too, my sprouts are smaller than the grocery-store ones, but sometimes sweeter. To harvest, twist each sprout off the plant, working from the ground up, or just cut off the entire stalk if you need a lot.
It’s a long haul to grow a vegetable like this, but these tasty bite-size cabbages are worth the effort, packing a couple of hearty meals on each plant. This year, why not give them another try?
Renewable, natural and compostable. Often available for free. Those are the main reasons why I’ve been making hoop house cloches with bamboo, and now’s the time to get some bamboo and try it, so they will be
ready for covering spring crops.
If you’ve heard my presentation on building a cloche, you know that I don’t think very highly of PVC. The white plastic pipe that is the standard product for building a hoop house cloche in our region is actually kind of a nasty choice. It’s the opposite of all those adjectives I used for bamboo.
I want to focus on how to make a cloche with bamboo, but first, a couple of quick comments about PVC.
Polyvinyl chloride pipe is a traditional plumbing product, quite necessary in some applications, and is readily available for only a couple of bucks a piece. But its cheapness hides its cost to the environment. In the manufacturing process, production of it gives off dioxins, a known carcinogen, which sickens workers and affects the environment. It’s not readily recyclable and would live in a landfill forever. (Learn more than you want to know at Wikipedia’s PVC page, which includes plentiful links to sources and studies.)
I used PVC for years, but as I learned more, I started to move away from it, and looked for other products for my cloche. Fortunately, I found a few options:
Each of these products has their benefits and drawbacks. Wire lasts a long time, but it is not very sturdy, so the hoops are a bit wobbly and have to be placed pretty close together. Wire mesh is more difficult to remove when you want to work in the bed. Fiberglass poles can get brittle and snap if made into a tight hoop, and I haven’t found ones that are very long, so a cloche made with them is shorter. Poly pipe, the black stuff used in garden irrigation systems, gets soft in warm weather and gets floppy (however, it doesn’t have the nasty manufacturing problems of PVC).
I have hoops made of all these products, but the one that I have the most hope for is bamboo.
It’s very flexible when it is young and after it’s just been cut. When it dries, it becomes stiff and holds its shape. Which means… it’s not just for teepee trellises any more!
Here’s how to make bamboo hoops:
1. Find a friend with a stand of bamboo , and cut a half-dozen culms that are 1/2 to 1 inch in diameter and 12 to 15 feet long. Look for pieces that are lighter-colored than the more mature, larger pieces. These will be more flexible. I’ve found bamboo to be more flexible in the spring, and have learned that it can’t be bent into extreme arcs. If you bend it too far or it’s too woody, it will break with a loud crack along the top of the hoop.
2. Strip off all the leaves. A sharp pair of pruners helps with this job. It’s OK to leave the stubs to be smoothed off after the bamboo has dried.
3. Cut off the very flexible top 2-3 feet. This part would bend or break quickly when used.
4. Cut off the stiff bottom end to make a stick about 8 feet long.
5. Stick one end into the ground 6-12 inches, along the inside edge of a raised bed that is 3-4 feet across. This works best with a raised bed made of wood or some other rigid structure, because the bamboo will exert force against it.
6. Grasp the other end with both hands and pull it slowly down into a hoop shape to the opposite edge of the raised bed, then also plunge it into the ground 6-12 inches. Make sure it is securely in place before you let go, because if it’s not, it could spring back out and whack you. Please try to avoid this; trust me, it’s painful.
If you don’t have a raised bed, an alternative method is to bend the bamboo between two other hard surfaces, such as a wall and a set of steps. Pick an out-of-the-way location, because it will have to remain there until it dries.
7. Repeat this process until you have as many hoops as you’ll need to cover your bed, spaced 12 to 18 inches apart. If you need extra help to hold the hoops into their shape, bind them tightly with plastic zip ties, which can be cut away when the bamboo is dry.
8. After a few weeks it will start to dry and you can use it, but it will take 2-3 months for it to completely dry and turn from green to brown. Once it’s dry, it will retain its hoop shape.
9. Trim off the rough edges of the leaf stubs at each node so there are no sharp edges that would rip the plastic. After it’s dry, you can smooth them with a file or sandpaper if necessary.
An 8 foot piece of bamboo placed into a raised bed that’s 4 feet across will yield a hoop that’s about 20 inches high. That’s plenty high for growing salad greens or root crops, or for getting your peppers and tomatoes off to a good start.
The hoops will last 1-2 years if the ends are in contact with the ground, longer if they are above the ground and tied to stakes.
This project will definitely continue to be an experiment, and I’ll update this post with any refinements to my technique. If you have tips, please drop me a note or a photo to share!
We had an unexpected snow here on Sunday, which was pretty significant. Late in the season for us, and it was more than just a dusting. So here’s what happened with my winter veggies.
I know I talk a lot about plants preparing themselves for winter, but these two photos of kale during the snow and after it had warmed up will show you the resiliency these amazing plants.
Same plants, I promise you!
Here’s the overall brassica bed in snow. Notice how the Brussels sprouts and dino kale in the background have also closed up to protect themselves.
And here it is after the snow has gone, and we returned to our normal, rainy, near-50 degree F. weather today.
They look positively chipper, don’t they?
Not to be outdone by brassicas, the Little Gem lettuce that I’ve been nursing all winter also fared quite well in the storm. Here are my two cold frames — the triangle tunnel and the box cold frame — after the snow has gone.
In these photos you can see the extra steps I took to keep these alive. In the triangle tunnel, I added floating row cover right on the plants, and then an extra, commercial tunnel cloche under the tunnel. Thank goodness it fit great. In the box cold frame, I added a layer of floating row cover, just laid on the plants. This was easy and took just a minute.
Two final photos. Today I took a close look at the dino kale (Lacinato), and saw a lot of bright green shoots coming from its tops. Is there
a better indicator of spring?