Posts Tagged ‘greenhouse’

Homegrown Vegetables Hall of Fame II: Leaf Lettuce

June 1, 2009

Sometime between when I was a child and the present, the world at large made a leap from iceberg lettuce to romaine.  Back then, every family had a volleyball-like, pale green head of iceberg lettuce in the refrigerator crisper.  Nowadays, the only times I see iceberg lettuce is at the Taco Bell or in a wedge salad.
This shift is understandable–iceberg lettuce is devoid of nutrition and flavor.  Romaine is able to hold up to heavy dressings and gets great ratings as  “leafy green”, one of the foods most people don’t eat enough of.  However, this shift in lettuce preference skipped over my personal favorite–leaf lettuce.  It’s easier to grow than either iceburg lettuce and romaine, and offers a far greater variety in form than either.  I can see why it doesn’t work as well on a commercial level–each head is a lot smaller than either iceburg or romaine lettuce, and it probably doesn’t transport as well, but for the home gardener, it’s ideal.

Growing Lettuce

Lettuce is a cool-weather crop, and will flower and set seed when it gets too warm.  In Michigan, I can usually get lettuce from my full-sun garden until the end of June.  If I start it in a cold frame, I can put it in in March, and start getting some thinnings in April.  A 4 x 4 area provides a few salads every few days through May and June, depending on weather.   This year, I’ve got some transplants and some grown from seed in the same bed, and they’re pretty indistinguishable at this point–next year, I’ll probably direct-seed them all.

Mulching is beneficial on two fronts–it keeps the soil moist and keeps the soil from splashing on the plant.  Lettuce likes a damp soil, and will wilt in hot, dry weather.  A good coating of mulch keeps the water in the soil from evaporating.  Mulch also keeps the soil in place through sprinkling or rain, as the leaves can get sandy otherwise.  Mulch with caution, however:  slugs love to eat lettuce, and too much mulch will give them the cover they need to destroy your crop.

Lettuce works well when planted in combination with other plants.   I’ve interplanted it with carrots, as the long and narrow carrot roots do not interfere with lettuce’s more shallow roots.  I’ve planted it between rows of corn, with the corn protecting the lettuce from the summer sun and extending its season.  I’ve also planted lettuce in a spot where I intend to plant a hot-weather vegetable–tomatoes or peppers, for example–as the lettuce will get pulled out when the hot-weather plants need the space.  There is some overlap in growing seasons, but the peppers/tomatoes don’t really get growing until the lettuce is past its prime.

I’ve had mixed results growing a fall crop of lettuce.  Timing is crucial–if you get it in too soon, the hot weather causes it to “bolt”, get bitter, and go to seed.  Plant too late, and the seedlings never develop.  I haven’t got a foolproof technique yet–I try it every year, and some years I have better luck than others.

Eating Lettuce

The first time I have to buy lettuce from the store (usually around November) is the most disappointing trip of the year.  After several months of right-out-of-the-ground lettuce, even the freshest grocery store offerings look tough, wilted, and bruised.  Fresh, home-grown lettuce is truly a luxury.  There are recipes for lettuce slaw and lettuce soup, but I’ve never needed them–a frilly leaf or two on a sandwich and a big salad are the only ways I’ve used lettuce.  We always offer to bring a green salad to the early-summer, bring-a-dish-to-pass events, too.  A few green onions, a shredded carrot, and a hardboiled egg, all topped with chive blossoms or pansy flowers, make for a very impressive, I-grew-it-myself salad and seems to go over well with most audiences.

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Winter Greens, Part II: The Cold Frame

March 22, 2009

This entry is a follow-up to my article on sprouts several weeks ago.

I planned on being able to post digital pictures before I wrote this, but that’s not happening.  In addition to sprouting various seeds, some home-grown and others from the store, I add fresh local vegetables to my winter diet through the use of a cold-frame.  I have had less than spectacular results, and a few meteorological mishaps, but the idea is worth sharing.

In my last entry, I gave a plan for an insulated straw-bale cold frame.  This year, I didn’t get enough bales before winter, so I used an alternate design–a variation on a hoop house.  I picked up about 75 ‘ of concrete reinforcing mesh–sort of an industrial-strength chicken wire with 6″ holes–to make tomato cages and a compost bin.  With the 15 or so feet I had left over, I made two sections that arced into a half-circle shape, about as wide as one of the beds in my garden.  Each section was cut to leave 6″ lengths of wire sticking out on the ends, which I stuck into the ground to secure the frame.  This left me with a wire tunnel, about 5 feet long, 4 feet wide, and 3 feet tall.  I was able to get some greenhouse-grade plastic (leftovers from a local greenhouse) to cover my frame, and weighed down the edges with some fist-sized rocks.  This left me with a miniature version of the full-sized greenhouses you’d see at a commercial-scale nursery.

The cold frame collects and retains solar energy, resulting in, well, a “greenhouse effect” that keeps the plants within at a much warmer temperature than the outside air.  Though this would only add a week or two to the life of warm weather plants, like peppers or tomatoes, it can keep cool-weather plants alive through all but the coldest Michigan winters.

Fall and Spring Planting in a Cold Frame

I stuck with cool-season greens in the fall, such as leaf lettuce, bok choy, and spinach, planted in the early fall or transplanted a little later.  These go more or less dormant when the weather gets cold, but the cold frame keeps them in a harvestable state through most of winter.  There isn’t a lot of growth, so your stock dwindles as spring approaches, but it’s a great way to keep some fresh and local food on the table all winter.  With no disrespect to the other two winter-long green vegetables, it’s way more interesting than kale, and far more versatile than brussel sprouts.

In spring, the cold frame is more of a head-start than a long-term plan.  Around the time I’m planting pea seeds, I pull out the rest of the winter greens from the cold frame (there’s usually not much left, and what’s left is starting to toughen up and flower), and plant a new crop.  This year, it was spinach, bok choy, leaf lettuce, and very early carrots.  The additional heat and humidity from the enclosed cold frame will give them several weeks of extra growing time before the open-air garden is ready to be planted.  I’ve sited the cold frame in the place I’m putting this year’s peppers, which won’t be planted until early summer, so most of these plants will have a chance to mature before the peppers go in.  I’ve considered putting the peppers in a few weeks before the last frost, hoping that the cold frame would give them the shelter and warmth they would need, but I don’t think it’s worth the risk.  I’m not sure how cold it can get in a cold frame, particularly at night.

Cold Frame Problems

Weather rarely cooperates with cold frame construction.  I’ve had my plastic sheeting blown off completely, despite weighing down the edges and clipping the plastic to the frame.  I’ve also had the entire thing collapse under the weight of snow and ice, crushing the leafy plants underneath.  Also, since the plastic sheeting is impermeable to rain, it can get desert-dry inside of a cold frame when all the ground moisture is frozen.

Access to vegetables is another problem.  With rocks weighing down the edges, water sometimes pools and freezes, making it hard to lift the plastic sheeting and reach in to harvest.  The 6″ access holes are also an obstacle.  I’ve adopted a “mass harvest” mentality, getting a week’s worth of greens in one go, just to simplify things.

Once spring starts to warm up, it can get very hot inside a greenhouse.  Think of a car parked in the sun with the windows up–opening up the cold frame on those warm, sunny days is a necessary inconvenience.

Weeds that are growing in the space where you’ve set up your cold frame are also able to take advantage of the microclimate, so they often spread throughout the winter.  Finally, keeping a bed in production all year takes a lot out of the soil, so your cold-frame bed should be refreshed with compost or fertilizer more often than others.

Possible Improvements

I’ve considered a number of options that I haven’t followed through on yet.  The first–instead of using weights to hold down the plastic, I’ve seen cold frames with trenches dug along their edges, with the edge of the plastic sheet buried under a few inches of soil.  This would hold it down a lot better, but would make it much harder to get into the cold frame.

Another modification would be to put it in so that it straddled two beds, with a path down the center.  I’d have to crawl in from the end (the taller a cold frame is, the less efficient it is, as heat rises away from the plants), but I wouldn’t have to reach, and I’d be able to bury the edges as mentioned above.

I’ve saved up a bunch of dark-colored laundry soap jugs, which I intend to fill with water and use as heat collectors.  The dark colors will absorb solar heat through the day, then release it at night.  Each jug takes up valuable square footage in the cold frame, though.

I may use a few stakes next year to reinforce the wire framework–I’ve never had a collapse before, but this year’s heavy snowfall brought the whole cold frame down.  It’s an easy enough fix, and I could have saved a few plants.

So far, using a cold frame has been more art than science, but it has kept in in the garden throughout the winter, and kept me out of the produce section of the grocery store for several weeks beyond the end of my garden’s regular season.  I’ll be building another straw-bale frame next year, provided I can round up enough free straw bales, but I’ll build another wire-frame hoop house as well, just to see if I can do any better.

The Giving Bale

February 19, 2009

With the first snowmelt of the year, I was reminded of the huge score I managed to pull a month or two ago.  I’ve got nearly a dozen straw bales in the backyard that I picked up from behind a church by my favorite library.  They were used for a pumpkin sale in October, and I checked in with them regularly while I worked up the courage to ask if I could take them.  It would have been great if I had asked immediately following the pumpkin sale, because by the time I picked them up, they were waterlogged and frozen together.  It took a great deal of effort to get them into the old hatchback, and I had to use a prybar to get two of them apart.

Even in an urban area, bales of straw aren’t too hard to come by–I’ve picked them up from curbs after people used them as harvest-themed decorations on their porch.  They’re incredibly useful in the garden, and I thought I’d run through the four seasons of straw bales in the garden, starting in the fall, when it’s easiest to pick them up.

Autumn

After they have exhausted their decorative usefulness, straw bales can be useful structural elements in the vegetable garden.  They can be used as ultra-insulated walls of cold frames or hot beds–I’ve arranged them into a rectangle around a few cold-season crops, like lettuce, spinach, or bok choy, and covered the opening with a plastic sheet to keep them available for harvest well into late fall.  A similar structure, filled with fresh horse manure and topped with potting soil, could keep warm (through the fermenting and decomposing manure) through the winter, providing you with fresh lettuce all winter.

I’ve also used straw bales to build a temporary compost bin.  After stacking them into a workable structure (usually a squarish shape, one bale by one bale, with the corners overlapping a little, two bales tall), I fill the center with yard and garden waste, which is usually spilling out of my over-filled compost bin in the fall.  A bit of high-nitrogen material, such as kitchen waste, manure, or grass clippings, will speed decomposition.  I let a good rain get it adequately damp, and put another bale or two on top to cover the opening.  This heavily insulated pile will continue cooking longer than my open-air bin, and when I build it on a garden bed, I can pull away the bales and spread the partly-finished compost in situ.

Bales can also be broken up into mulch, and a thick coat of coarse straw spread in the fall can protect topsoil by slowing and absorbing rain and melting snow  .

Winter

Straw’s insulating qualities are even more important in the winter.  The cold-frame and hot beds build in autumn will continue producing into winter, and there are other uses, as well.  A structure similar to the compost bin can be build for root storage, with layers of carrots, beets, turnips, or rutabegas piled inside and separated with layers of loose straw.  I haven’t tried this method, as I’m not producing enough food to store during the winter, so attempt it with caution.  I’d advise lining the inside of the bale-house with chicken wire to keep out rodents.

Whole bales can also be used to insulate tender plants through the winter.  I grow artichokes, which are not cold-tolerant enough to survive a Michigan winter, but keeping them well-insulated and close to the house seems to work.  If you keep parsnips or carrots in the ground though winter, covering them with strawbales will make harvest a little easier, at least until everything freezes solid.

Spring

Cold frames can be replanted, and hotbeds can have the spent manure dug out and replaced for a fresh start.  Hotbeds are a great place to start seedings, as bottom heating encourages germination.

As seedlings sprout, cool-season plants can be mulched with straw to supress weeds, keep the soil cool, and prevent mud from splashing up onto your leaf crops.

A muddy garden path is easily remedied with the generous application of straw.  I’ve laid it down a foot thick down the middle of the garden so that I could wear my dress shoes out to the compost pile.

If you turn your compost heap in the spring, chances are it’s a heavy, waterlogged pile.  If you’re not ready to spread it, restack it parfait-style with a 4-8″ layer of fluffed straw every foot or so.  This allows oxygen into the pile, and hastens decomposition.

If you’re into nature, there’s some delight in watching the birds steal straw to build nests.  It’s not quite so delightful to find mice using your straw as a nest, but I’ll avoid that digression.

Summer

By summer, last fall’s straw bales will have started to decay, and the string used to hold them together has probably deteriorated to the point that you couldn’t pick the bale up if you wanted to.  They can be used in place, or broken up for mulch.

When I plant corn, I lay on a thick, loose layer of straw.  This keeps the sun off the soil, so I wait until it’s warmed up, but it seems to prevent birds from pulling up the seedlings.  The corn is determined enough to push through a few inches of straw.

If spring’s hotbeds have cooled sufficiently by melon-planting time, put a few melon plants in each one.  The recently-decomposed horse manure will retain a lot of water and provide the plants with the rich soil they need to produce.  If you have any bales placed on the ground sideways (with the individual straws running perpendicular to the ground), you can poke a hole in them for tomatoes.  If regularly fertilized, they do well with their roots digging into the consistently moist, decomposed straw.  Some of the shorter varieties won’t need staking, as they can spill over the sides of the bale.

When the soil has warmed enough, straw is an ideal mulch.  A well-rotted bale can be pulled apart in “pages”, the thick, matted masses of straw.  These pages are laid down between rows of plants, and are pretty well impenetrable to weed seedlings.  Established weeds will push through, but the shady, moist soil under the straw makes it a lot easier to pull these out.  The straw breaks down very slowly, so it’s ideal for retaining moisture, preventing the rain from washing away soil, and slowing the breakdown of organic material.  By midsummer, my entire garden is covered in a thick layer of straw.

By the end of summer, I’ve usually worked through the straw I’ve collected, regardless of how much I started with.  If I’m planting a fall crop, I’ll clear a bed of straw and add it to the compost pile, where it adds carbon and bulk, absorbs water, and admits oxygen.  If I’m leaving the bed alone after summer harvest, I won’t clear the mulch until the spring.  I occassionally have to pull up some wheat sprouts–from seeds stowing away in the straw–but they don’t put up much of a fight.  Should I ever get the rabbits I dream of, I’ll feed the sprouts to them.  I may sing the praises of stealing your neighbor’s bags of leaves in the fall in a later entry, but I’m comfortable starting my tribute to high-carbon organic mulches with straw.

I’ve Got Worms

February 21, 2008

Seeing as I’m writing a weblog on local foods in the dead of winter, I hope I can be forgiven for a slightly off-topic entry. Yesterday, I recieved a belated Christmas gift–a pound of red wriggler composting worms. My in-laws live in Kalamazoo, which would be ground zero for the worm-composting movement, if there were such a thing. The author of Worms Eat My Garbage, now deceased, lived there, and her organization continues to sell worms and vermicomposting supplies. Because this particular species of worm is cold-sensitive, I couldn’t have them sitting on my doorstep until I came home. My exceedingly generous and accomodating father-in-law delivered them on a trip through town.

Vermicomposting Basics

I’m trying to make this weblog beginner-friendly, so I’m going to run through the basics here. If you know anything about composting with worms, this next section is worth skipping.

Unlike the earthworms we’re familiar with in the Great North, red wrigglers spend all of their time very near the surface, where the soil is composed of mostly organic material. Because they don’t burrow and hibernate like earthworms, they won’t survive through a heavy or deep frost. They are, however, well suited for close quarters, and are able to convert an impressive volume of organic waste into “castings”, or worm manure.

My “worm bin”, which I prepared ahead of time, is an opaque Rubbermaid-style storage bin. I filled it about 3/4 full with shredded 2006 income tax instruction forms (available mid-April by the thousands at your local library) and wet the newsprint down. As recommended by Worms Eat My Garbage, I added 3 times the weight of the paper in water, aiming for a damp-not-soggy moisture level. More on this later. The worms “chew” by grinding food up with soil particles in a gizzard, so I added a dead houseplant, with its soil, to provide some grit. On top of it all, I dumped my worms. I left the lid off until the light-sensitive worms retreated into the newsprint bedding. I made my first deposit, burying some moldy home-baked bread under an inch or so of wet, grey paper.

The Process So Far…

The next morning, I eagerly checked in on my worms. Apparently, my bedding was too wet, which provided me with a truly horrifying first morning with my worms. Worms, as it turns out, breathe through their skins, which must be kept moist. If it’s too moist, however, they start to drown. This is why the sidewalks are covered with waterlogged earthworms after a good rain. Not having a sidewalk available, my worms climbed out of their too-wet bedding and congregated along the upper lip of the bin.

Now, I’m not the squeamish type, but hundreds of squirming, bloated redworms are an unpleasant sight, somewhere between a horror film and the sex-ed photos of STDs in their advanced stages. I added some more dry newsprint to balance the moisture level, pushed my worms back into the fray, and hoped for the best. This afternoon, things seemed to be on the level, so I think I’m OK. I hope to find all of the dessicated remains of escaped worms before my wife does.

Good Intentions

The plan with the worm bin, and the connection with the whole local-food thing, is pretty simple. The castings are a nutrient-rich plant food, like any manure. Unlike most animal manures, it can be applied to plants fresh. Also unlike most animal manures, I don’t have to drive ten miles out of the city to get it. This, along with the “worm tea” that can be drained off, will be put to use in my greenhouse to get my seedlings off to an organic start. Last year’s greenhouse seedlings were a pretty pathetic lot, because I didn’t fertilize them. This year, I may have to resort to a dilute chemical fertilizer until my worms get their act together. The most frequently suggested organic alternative, made out of fish waste, is a little scary in terms of heavy metal (lead, mercury, &c.) content, and I’d sooner use a known chemical than an unknown contaminant.

An added benefit is that I’ll be able to continue composting without making the long, long journey through the deep, deep snow to the compost bin at the far end of the yard. A bin in the basement makes for a much more enticing trip, which may result in a more-often-emptied slop bucket. Most of our vegetables come from produce we froze last summer, so there isn’t a lot of waste being produced. Hopefully, our worms can keep up with production. My complimentary book says that my worms can process 1/2 their collective weight in garbage a day, so this should work out.

In Other News

I filled the last of my seed needs at the sales at my local Flowerland, and have thinned my flats of lettuce, spinach, snapdragons, and annual poppies. The asparagus has not yet sprouted, but I think I’m still within their germination window.

As I watch the footage that inspired our nation’s largest-ever meat recall, I had to face my biggest why-aren’t-you-doing-this-already food problem–meat. I gave up vegetarianism a few years ago (for reasons I may get into later) and didn’t develop my meat-buying instincts while I was learning how to shop for myself. I’ve decided that I don’t want to be eating cows that are too sick to walk onto the killing floor, and will finally start choosing local meat when it becomes available at the farmer’s market.

Meanwhile, I am buying increasingly unprocessed cuts at the grocery store. Last week’s shopping trip saw the move from frozen, boneless, skinless chicken breasts to fresh, boned, skinned chicken thighs, and this week I bought a whole bird. I think I’m going to roast it, Thanksgiving-style. I might cut the next one up, depending on how that goes. My aversion to local meat in the past stemmed from the fact that I didn’t know how to handle an entire bird, or unground chuck, or what have you, so I’m going to be ready this year.

Winter Foraging, and Preparing for Spring Gardens

February 9, 2008

Back in the day when human beings depended on foraging for survival, there was not, I suspect, a lot of people spending winters in the Michigan area. I started this weblog as motivation to try new local and wild foods, but my decision to start in the dead of winter may have been a little misguided. Regardless, I’ve come up with a few snowbound topics.

Rose Hips

Not quite “wild”, but definitely local–the rose bush in my backyard, the last survivor of three planted by the previous owner, bloomed fairly well this year. I dutifully dead-headed, cutting off blooms that were past their prime. This ritual stimulates the rose to continue blooming. As fall approached, I let the rose blossoms mature, lose their petals, and set fruit. The orangey, marble-sized hips remain on the bush throughout winter. They are reportedly rich in vitamin C, which is not easy to come by locally in midwinter.

I prepared the hips in the recommended manner–gather a handful, pour hot water over them, and let steep for 10 minutes. This results in a pinkish intiction that was no great pleasure to drink. It may be the variety of rose (some may taste better than others), or the quality of the hips–by the time of harvest, mine had been through several freezes and thaws, with temperatures from freezing up through the seventies and back to freezing again. Like the brussel sprouts still frozen in my backyard, which are cooking up mushy these days, the rose hips may have seen better days. I will definitely try this earlier next season, and will try new varieties, but would have to be looking scurvy in the eye to revisit the beverage I’ve just finished.

Starting Seeds

In the dank, moldy shower stall in the corner of our basement, I’ve set up a two-level greenhouse to get a head start on the growing season. It’s a pretty crude affair–two scrap lumber frames, covered in lathe slats, with some discount flourescent lighting rigs. I lined the glass door with aluminum foil to reflect the light back into the shower stall, and have all of my lights plugged into a single powerstrip, which allows for easy on-off every morning and evening. To the casual observer, it looks an awful lot like I’m growing marijuana on a commercial scale. My digital camera is not functioning at the moment, but I’d like to provide some pictures in the future.

It’s well ahead of our last frost-free date (sometime in May), but I started a few things this week. In addition to some early flowers, I’ve got spinach and lettuce, which will go into the cold-frame for an early salad crop, and asparagus. Last year, the asparagus I grew from seed was completely eaten by slugs within two days of setting it out. I then purchased two dozen year-old roots, which will be entering their second year this spring (harvest is supposed to start at the three-year mark). By starting from seed again this year, I put myself a year into the hole and risk another slug attack, but I’ll save a considerable sum of money over buying roots. I also feed into an illogical drive for legitimacy, according to which growing from seed is more respectable than any shortcut. If my seed-starting fails again this year, I’ll be humbly purchasing and planting asparagus crowns when the soil can be worked.