Archive for March, 2011

Grow $700 of Food in 100 Square Feet!

I took a 5-by-20-foot section of garden bed by my tiny lawn to see how much I could grow in just that 100 square feet. I wanted to produce a lot of food, and because it was part of my edible landscape, it had to look good, too.

The Plants

I wanted to make this garden simple — something anyone in the United States could grow. I didn’t include fancy vegetable varieties; I chose those available at my local nursery as transplants. I also selected vegetables that are expensive to buy at the supermarket, as well as varieties that my experience has told me produce high yields.

The first season (spring/summer 2008), I grew the following:

  • Two tomato plants: ‘Better Boy’ and ‘Early Girl’
  • Bell peppers, which are often luxuries at the market when fully colored: two ‘California Wonder,’ two ‘Golden Bell,’ one ‘Orange Bell,’ and one ‘Big Red Beauty’
  • Four zucchinis: two green ‘Raven’ and two ‘Golden Dawn’
  • Four basils (expensive in stores but essential in the kitchen)
  • 18 lettuces: six ‘Crisp Mint’ romaine, six ‘Winter Density’ romaine, and six ‘Sylvestra’ butterhead

The only plants I grew from seed were the zucchinis. Hindsight is always 20/20; I should have thinned each of the zucchini hills to a single seedling, but I left two in each hill. As a result, I needed to come up with creative uses for zucchini, including giving them away as party favors at a dinner I hosted.

It looked a bit barren at first, but the garden flourished — especially the lettuces. Within several weeks, I started picking outer leaves for salads for neighbors and myself. The weather forecast predicted temperatures in the upper 90s. I was heading out of town and feared the lettuces would bolt, so I harvested the entire heads earlier than I normally would. Within about a month of transplanting the lettuces into the garden, I had grown enough for 230 individual servings of salad. And by that time, the tomatoes, zucchinis and pepper plants had nearly filled in the bed.

A Living Spreadsheet

Although I’ve grown hundreds of varieties of vegetables over the years and kept rough notes, this garden was different.

We created spreadsheets for each type of plant, and we kept meticulous records each time we harvested. We recorded the amount — pounds and ounces, as well as number of fruits (for each cultivar of tomato, zucchini and peppers) or handfuls (for lettuces and basil).

The Investment: Time and Money

This 100-square-foot plot took about eight hours to prepare, including digging the area, amending the soil, raking it smooth, placing stepping stones, digging the planting holes, adding organic fertilizer, and setting the plants and seeds in the ground. On planting day, I installed homemade tomato cages (store-bought ones are never tall or sturdy enough) and drip irrigation. And I mulched well — a thick mulch is key to cutting down on weeding, which is the biggest time waste in the garden, in my opinion.

We hand-watered the bed for a few weeks to allow the root systems to grow wide enough to reach the drip system. Three times over the first month we routed out a few weeds, which was only necessary until the plants filled in and shaded the soil.

Tomatoes in my arid climate are susceptible to bronze mites that cut down on the harvest and flavor. To prevent mites, we sprayed sulfur in mid-July and again in mid-August, which took about 30 minutes each time. In rainy climates, gardeners often need to prevent early blight on tomatoes. To do so, rotate tomato plants to a different area of the garden each year and mulch well. After the plants are a few feet tall, remove the lower 18 inches of leafy stems to create good air circulation.

For the rest of the season, we tied the tomatoes and peppers to the stakes as they grew upward, cut off the most rampant branches, and harvested the fruits. The time commitment averaged about an hour and a half each week. (Our harvesting was more time-consuming than average because we counted, weighed and recorded everything we picked.)

To determine what my harvest would cost in the market, I began checking out equivalent organic produce prices in midsummer. On a single day in late August, I harvested 49 tomatoes, nine peppers, 15 zucchinis of many sizes, and three handfuls of basil — which would have totaled $136 at my market that day.

From April to September, this little organic garden produced 77.5 pounds of tomatoes, 15.5 pounds of bell peppers, 14.3 pounds of lettuce, and 2.5 pounds of basil — plus a whopping 126 pounds of zucchini! Next time I won’t feel bad about pulling out those extra plants.

I figured the total value of my 2008 summer trial garden harvest was $746.52. In order to get a fair picture, I also needed to subtract the cost of seeds, plants and compost (I can’t make enough to keep up with my garden), which added up to $63.09. That leaves $683.43 in savings on fresh vegetables. Of course, prices vary throughout the season and throughout the country. 

  • Choose indeterminate tomatoes. They keep growing and producing fruit until a killing frost. (Determinate varieties save space but ripen all at once.)
     In spring, plant cool-season vegetables, including lettuce, mesclun and stir-fry green mixes, arugula, scallions, spinach and radishes. They are ready to harvest in a short time, and they act as space holders until the warm-season veggies fill in.
  •  Grow up. Peas, small melons, squash, cucumbers and pole beans have a small footprint when grown vertically. Plus, they yield more over a longer time than bush types.
  •  Plants such as broccoli, eggplant, peppers, chard and kale are worth the space they take for a long season. As long as you keep harvesting, they will keep producing until frost
  • Mini Coldframe easy to build

    A Greenhouse for $20 -$30
    Build a cold frame for spring

    Lately I’ve been in one of those claustrophobic winter moods where I’m not sure I can stand living in the northern hemisphere for three more months.

    So to convince myself that summer is a little closer, I built a cold frame and started buying seeds.

    Artisans’ work featured on this Episode


    • Recycled window – roughly 32″x26″
    • 1×6 cedar fencing
    • 1×6 cedar decking
    • 1×2 cedar
    • 3 – 2″ hinges
    • About 50 – 1-1/2″ exterior grade screws
    • 16 – 1-1/4″ exterior grade screws
    • 1 – 3″ x 1/4″ carriage bolt, two washers and a nut to fit
    • Thread adhesive

    • Drill or screwdriver, bits
    • Handsaw or circular saw
    Cut List:

    • Back: Two – 1″x 6″x 30″ (thicker cedar)
    • Front: One – 1″ x 6″ x 30″
    • Floor: Five – 1″ x 6″ x 30″
    • Sides: Four – 1″ x 6″ x 24-1/2″
    • Braces: Four – 1″ x 2″ x 10-1/2″
    • Arm: One – 1″ x 2″ x 12″

    Measure the window in both directions

    The box will be smaller than the window so that the rain will drip off

    The back pieces are thicker than the sides and bottom

    Screw the first layer of the frame together, and put floor in place
    Build a box that measures approximately 2″ smaller than the overall dimensions of your window. This allows a bit of overhang on the front and sides.To build the first layer of the box, pre-drill and screw the sides to the front and back. Use the stronger, thicker decking boards for the back to provide extra strength where the window will be hinged. Then attach the front.

    Use a screw long enough to get a good grip on the end grain

    Mark the final flooring piece that will require cutting

    Install the piece in the bottom
    Once the first layer of the box is screwed together, set the bottom pieces in place. If there is a large gap in the floor, lift the frame and slide a board in place under it. Then use a pencil to trace a cut line to custom fit that last board. Cut and slide the board back in place and attach all the floor boards with screws through the sides. (Be sure to pre-drill before driving in the screws.)

    Install a vertical brace in the corner

    Attach the second level to the brace
    Attach the 1″ x 2″ corner braces to the inside back of the frame using 1-1/4″ screws. Then screw the top board to the corner braces to complete the back.

    Use a straight edge to scribe the cutoff angle

    Cut the side piece and install it with screws
    Make the angled sidepieces by holding a 24″ fence board on top of one of the existing sides. Use a straight edge to draw the angle from the top back down to the level of the front. Cut one angled board for each side.

    Install a brace in the centre of each side for added support

    Completed box without window

    Detail of finished side
    Attach the angled sides to the frame with screws through the back and one more through the tip of the angled board. Add a vertical brace in the center of the each side and secure it in place with screws through both boards.

    Remove the old hardware and flashing from the window

    Attach the hinges to the back of the frame

    Choose best side of window for hinging

    Pre-drill and screw the hinges and window together
    Remove old hardware from the window, then prime and paint any exposed wood. Attach three hinges to the back of the frame, then attach the window to the hinges leaving equal overhang on both sides.

    Install a support arm for the window

    Cold frame with support arm installed

    Completed box with window
    Make an arm (to hold the window open while working inside the box). Drill one 1/4″ hole through the three layers: the side, the vertical support and the arm itself. Pass a carriage bolt through the hole in the side, place a washer on the bolt and then pass the bolt through the support arm. Add another washer and finally a nut. Use thread adhesive to lock the nut in place leaving the arm a bit loose so that it can move freely and easily.
    Voila – you now own a cold frame!

    Lid propped open
    But here’s the thing. Don’t plant your tomato seeds too early or they’ll be ripe earlier than anyone else’s and then they’ll be gone earlier than anyone else’s and then next winter is going to seem even longer.

    Stevia – Zero Calorie Sweetener that you can Grow

    Stevia (stevia rebaudiana) is a new world herb that you might have only recently heard of.  Stevia leaves – while having zero calories – are claimed to be 30 times sweeter than sugar, and in fact one of the common names is “candy leaf” – the extract is supposedly 300 times sweeter than sugar!  Stevia is also reputed to have several health benefits including the  prevention of tooth decay and diabetes.  I don’t know about that, but I would guess that using less sugar probably would have those effects.

    Is the idea of growing your own natural organic zero calorie sweetener intriguing to you?

    These Stevia plants are 3 weeks old. These Stevia plants are 3 weeks old. 

    I’m growing stevia for the first time this year from Burpee brand seeds that I bought at a local home improvement center.  I had heard that stevia was very hard to start from seeds, but I got about 50% germination rate by using bottom heat, keeping them very warm, continuously damp, and supplying 17 hours / day of florescent light.  After 3 weeks I have 6 healthy looking (if a bit slow growing) plants from the dozen or so seeds that came in the pack.  Since I have so few I’m being extra careful with them right now, and making sure that they stay above 50 degrees at all times.

    I haven’t really found very much culture information about stevia yet other than that they don’t tolerate cold temperatures, and are a bit hard to start from seed, but easy to start from cuttings, and have few if any insect pests.  I also heard from a fellow in Australia that they grow almost as weeds there because they self seed.  He said that among other uses they put the raw leaves in salads.  I have in mind to try it in some herbal tea mixes, and perhaps brewing a tea with it and using it as a condiment.  I also hope to save my own seeds and perhaps over winter a plant or two next year.  Maybe I’ll sell a few starts at the farmers market if all goes well.

    Until very recently it was not legal to even refer to stevia as a sweetener in the United States despite it’s very long record of benign use in other countries around the world.  Stevia could only be marketed as a dietary supplement in the U.S. –  But, now that the sweetener industry is ready to roll out their own stevia products that law has been changed.  Guess who lobbied the FDA to keep it illegal as a sweetener all those years?

    Anyway, you might want to consider trying to grow stevia in your garden this year – if you do, let me know how it goes.

    Simple Plastic Tunnel Cold Frame or Row Cover

    This plastic tunnel is being used inside of the greenhouse to protect tender plants against a late hard freeze - very effectively I might add. This plastic tunnel is being used inside of the greenhouse to protect tender plants against a late hard freeze – very effectively I might add. 

    A simple plastic tunnel like this can serve as a cold frame to grow salad greens  all winter long, to grow out tomatoes and other tender plants, to extend the season for an early Spring start or a late Fall harvest, or even as a screen house to keep birds off of your strawberries or vine borer moths off of your squashes.  You can also use one of these to dry out water logged beds and warm up the soil so that you can begin planting  in early Spring. These devices are so useful, cheap, easy, and quick to build that everyone should have at least one – it’s almost as good as having your own polytunnel greenhouse

    materials for plastic tunnel row cover materials for plastic tunnel row cover 


    • 5-5? lengths of 3/4? (inside diameter) polyethylene water pipe
    • 10 – 1/2? x 1/2? x 14? wooden stakes
    • 1 – 12? x 6? x 4 mil clear plastic sheet
    • 4 – 1/2? x 1 1/2? x 8? wood strips
    • staples and nails.

    As usual you can (and should) substitute materials that you have available on hand.  You can use anything for stakes that are strong enough to drive into the ground and will slip inside of the rib pipes. You can use a broom stick, piece of pipe or any long thin objects for the poles, and you can fasten the plastic skin to the poles with duct tape instead of staples.  Clearly almost any kind of bendable pipe can be used for the ribs, but here’s a tip – contractors or plumbers are likely to have a scrap collection of one kind of plastic pipe or another that comes in coils that they will either give away or sell incredibly cheap – just ask.  In the worst case, you can usually buy cut lengths at the home improvement or hardware store. 

    This design is also great for hardening off.  The cover can be opened or closed in about a minute by one person.  The whole thing can be moved to a new location and set up in 15 minutes. This design is also great for hardening off. The cover can be opened or closed in about a minute by one person. The whole thing can be moved to a new location and set up in 15 minutes. 

    Start by cutting your parts to size – this tunnel will cover an area that is from about 2 – 3  feet wide and the black pipe for the ribs are 5? long, and the plastic is about a foot and a half wider – you can roll up any excess plastic on the poles so it is better for it to be too wide than too narrow.  In this case I made the poles shorter than the plastic so that the excess could be used to close up the ends, but you could also make the poles the same length as the plastic and use rectangles of plywood or other sheet lumber to close up the ends.  Use your imagination. 


    Once you have your parts cut to size fasten the poles to each long edge of the plastic sheet.  I used staples to do this, and then rolled the plastic around one piece of wood and fastened another strip to it so that the plastic is sandwiched between the wood pieces.  If you are just using tape, then you will want to wrap the plastic around the pole and tape the plastic sheet back to itself forming a tube with the pole inside – tip: construction tape (duct or housewrap tape) sticks very well to plastic, and not very well to wood – don’t try to tape to the wood other than as a temporary measure. 


    Once you have that done, roll the plastic up around one of the staves until you are ready to deploy it. 

    The ribs just slip over the stakes - you can probably get by with ribs that are much further apart than this if you want. The ribs just slip over the stakes – you can probably get by with ribs that are much further apart than this if you want. 

    In the garden, simply drive the stakes into the ground where you want them, and slip the pipes for the ribs over them.  Since my ribs are made out of coiled pipe they already have the right shape, if you used straight sections of pipe you might need to use something more robust than 1/2? wooden stakes to hold against the tension of the polytunnel ribs. 

    Now just roll your plastic out over the ribs and there you have it.  If you experience a lot of wind you might need to weight down the plastic a bit, but under normal conditions the wooden pole will probably do the trick.  When you need to get into the pollytunnel you just lift a pole and lay it over the top – almost as easy as a regular cold frame, but a lot easier to build or move. 

    Now would be a good time to build one! 

    Cold Frame

    Successful seed-starting takes infrastructure, be it a tricked-out heated glass greenhouse or a fluorescent shop-light setup in your basement. Either extreme–or anywhere in between–can work beautifully. However, in my experience, the solutions that are most likely to be implemented by busy gardeners are those that feel accessible and do-able in occasional spare moments.

    This post covers one such solution: a cold frame constructed from easy-to-find, fairly inexpensive materials.


    I’m a huge fan of cold frames. Not only do they hold miraculous quantities of promising green growth within their simple walls, they also are easy to build and will happily bring through the winter many servings of cold-hardy crops like spinach, scallions, tatsoi, and mache. Here’s a cold frame that a reasonably handy person with some power tools can put together for about $100 with materials from a local lumberyard (or, unfortunately, big box store–see below). In one season alone, you can easily produce several hundred dollars worth of seedlings in this frame’s roomy 32 square feet.

    Materials List

    * 2 pieces 8-foot-long, 26-inch-wide TUFTEX polycarbonate panels — $40
    * 2 packs closure strips — $10
    * 1 box TUFTEX screws — $6
    * roll of tape sealant (often used for metal roof panel overlap joints and similar) or some silicone caulk — $10
    * 2 pieces 8-foot 2×12 SPF lumber — $20
    * 1 piece 8-foot 2×8 SPF lumber — $8
    * 7 pieces 8-foot 2×2 SPF lumber, as straight as you can find — $13
    * exterior-grade drywall screws: 1-5/8? and 3? — $6
    * Hinges – $6

    Tools List

    * Circular Saw
    * Drill with 3/16? drill bit, Philips head driver bit, and 1/4? hex driver bit
    * Optional but makes things a little easier: Chop Saw

    All of these materials can be obtained from Evergreen Supply.  I like to give as much of my business as possible to my local lumberyard, as I appreciate having a locally owned lumberyard so close to home. I want to support them.

    Once you’ve assembled your materials, here’s what to do:

    1. Cut each TUFTEX panel in half so that you end up with four panels that are each 26? wide by 48? tall. This is best accomplished with a circular saw, though tin snips will also do the job.

    2. Arrange the four panels so that they are spread out across a flat surface with the last rib on one panel overlapping the first rib on the next. Try to get them as straight and square as possible.

    3. Measure the distance from the bottom of the first space-between-two-ribs to the bottom of the last space-between-two-ribs. This should be somewhere in the neighborhood of 8 feet. It won’t be exact, but that’s okay.

    Make the Frame for the Lid

    1. Miter cut the ends of two of the 8-foot 2×2s at 45-degree angles, like a picture frame’s corners.

    2. Cut one of the other 2×2s in half. Miter cut the ends so that the long edges are 48?, like a picture frame’s corners.

    3. Attach the 2×2s at the mitered corners by pre-drilling to prevent splitting and then attaching the ends together using 1-5/8? screws or similar. The result should be a giant picture frame, basically.

    4. Cut another 2×2 to about 93? in length. Don’t cut it too short! Place it in the center of the frame, centered 24? from top and bottom corners. This creates a middle horizontal support parallel to the other long sides of the frame; this will prevent the frame from sagging under the weight of adhered interior dew or exterior snow loads.

    Finish the Lid

    1. Using the drill bit, pre-drill holes in every other “valley” of each panel’s ribbing along the top and bottom edges.

    2. Place strips of tape sealant along the top surface of the short sides of the frame. (Or, use silicone to seal this seam after step four. Place TUFTEX closure strips along the tops of the long sides of the frame.

    3. Line up the panels on the frame so that they are overlapping and cover the entire frame, setting them on top of the closure strips. Set the final “valleys” set so they are resting on the tape sealant (or, again, you can fill this seam with silicone caulk). This won’t be a perfect match–the edges of the valleys will touch the sides of the frames, but they won’t rest on it nicely. This is okay. Just be sure this gap is sealed (it may take a few layers of tape sealant, some applied after the cover is attached.

    4. Attach the panels using the TUFTEX fasteners and the hex-head driver bit.

    Make the cold frame box

    1. Cut one of the 8-foot 2×12’s into 2 45? lengths.

    2. Using a straight edge, draw a line from the top corner of one end of the length to a mark at 7-1/4? from the bottom corner of the other end. Cutting on this line will create a side to the cold frame that will slope exactly from the rear 2×12 wall to the front 2×8 wall.

    3. Using a circular saw, cut along this line. Be careful–it can be tricky to perform this cut, as it’s something of a ripping cut that sort of follows the grain.

    4. Repeat for other 45? length.

    5. Position the pieces of the cold frame. The two 8-foot pieces of lumber are parallel, with the two 45-inch pieces of sloping lumber forming the sides, with the un-ripped side up. These smaller pieces should be “inside” the 8-foot pieces so that, when sandwiched, the entire length of the side is 48? (including the 1-1/2? for the ends of both the rear and front walls).

    6. Pre-drill holes and attach all sides of the frame using the 3? screws.

    7. Half-way down the short sides of the cold frame, attach a spare piece of wood to the inside top edge, flush with the sloping surface of the side.

    8. Flip the cold frame over. Cut one of the three remaining 2×2’s into 2 45? lengths. Match these up with the undersides of the lumber that makes the frame and attach with the 3? screws. This will be the “ground floor” of your cold frame that will slowly rot over several years. After it’s rotted, simply detach and replace with a new “ground floor.” The rest of the cold frame will last for about 20 years or so if left out–maybe more if stored well when not in use. (The ground floor is not shown in the accompanying photos.)

    Put the Lid on the Cold Frame

    1. Set the lid on the cold frame, matching up the corners with the frame.

    2. Attach to the cold frame using a couple of long rectangular hinges and short screws.

    3. If the lid does not sit squarely on the frame, purchase and install a latch to hold it snug.

    VOILA! A functional cold frame that can be built in an afternoon for around a hundred bucks. Fill it with trays and go to town! You’ll find endless uses for it.

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