Wednesday, January 25, 2012

The Square Foot Method

Cover of All New Square Foot Gardening

I've mentioned the Square Foot Garden or SFG Method several times so far.  This method was developed by a man named Mel Bartholomew who realized that the standard row method of gardening was wasteful and produced poor results, so he developed a different (and in some ways better) method.
Mr. Bartholomew's Square Foot Method of gardening has some advantages, less water, less space needed, more produce grown.  It is adaptable, easy to understand, and lends itself well to the backyard gardener.  The method stems from the idea that plants need a particular spacing to do well and rather than fill widely spaced rows with carrots 3" apart, you build a small raised bed that you can reach all the way around, divide it into one foot squares and plant a different crop in each square, spaced according to recommendations.  With this method a 4 foot by 4 foot bed will have a total of 16 square feet, each of which is planted with a different crop; one tomato, 4 lettuce, 16 carrots, 8 peas, 2 cucumbers, etc.  Each square contains the appropriate number of that crop based on seed spacing guidelines.  So a 12 inch by 12 inch square can support 16 carrots, evenly spaced in 4 rows of 4 seeds, each 3" apart.

Mel also realized that his garden beds only needed to be 6" deep, very few plants required more than that depth for root growth.  Originally he used 1 foot deep beds, but discovered that the extra depth was wasted and eliminated it.  He filled his beds with "Mel's Mix" a blend of compost, peat moss and vermiculite or perlite that he discovered was perfectly suited for growing vegetables, while staying soft and fluffy, rather than compacting or developing a crust like many soils.

With Mel's Mix he could fill a bed with the perfect soil for far less cost than repeatedly improving the soil in the ground.

Mel's books cover everything needed for a SFG garden, most of the information is very useful, some of it is just a reflection of Mel's own tendencies to be precise and linear.  \

In general I think the book is worth reading, which is why I list it in my Recommended Reading links.  Mel suggests laying out a permanent grid over the top of the bed to show the squares though, while he is right that this is a way to save time during planting, I dislike the straight lines of the grid showing amidst the wild tangle of plants.  It's just too structured for my taste.  Instead I go out each spring and lay tape over top of the beds to show my grid, do all my planting and then remove the tape.  Also, Mel suggests mixing things up to confuse pests, and while I think the idea is sound, I find I still end up with a straight row of peas; I can't fit them all mixed in with other plants because they require trellising.

Not all of Mr. Bartholomew's advice is useful to everyone.  The primary things I got from his books were:  bed size --make beds small enough to be able to reach every square easily; soil --Mel's Mix is relatively inexpensive and gives more bang for your buck; plant spacing --a small space can easily grow far more than you'd expect.

Last summer was the first time I tried using the SFG method, and I have to say it worked remarkably well. I was very happy with the production of my garden.  This year I plan to try pushing the limits of the SFG method by planting my larger plants by the square, then small root crops like green onion, carrots, radishes and garlic will be planted in rows between each square.  I am hoping that a few small root veggies won't crowd the larger fruiting veggies too much and will save me a few squares of planting space that can be used for larger plants.

In conclusion, buy or borrow from the library Mel Bartholomew's book.  Look it over, see what you can find in it that may prove useful.  I can attest that his methods have proven themselves in my garden and would love to hear about other successes (or failures!), and what has been helpful to other gardeners.


  1. Are your beds really only 6" deep? That just doesn't seem like enough room for the roots!

    1. Yes, and no. My larger beds were built before I learned about the square foot method, and the whiskey barrels are, of course, deeper than 6". The small bed I refer to as the "pumpkin bed" is only 6" deep though. Most plants like leafy greens, broccoli, squashes, and legumes such as beans and peas don't actually have deep root systems. Root vegetables like potatoes, carrots, and turnips do tend to have deeper roots. You obviously can't grow an 8" long carrot in only 6" of soil. So long as the shallow rooting veggies have adequate nutrients and water, and lateral room to spread they seem to do fine in the shallow beds. If you are importing soil and amendments this can save you a lot of money! A bed of pumpkins, zucchini, onions, beans, peas, lettuce, kale, spinach... everything should grow just fine. The only real issue develops if there is a shortage of moisture or nutrients, which can happen quickly in a full bed of veggies with only 6" of soil. Normally a plant in dry soil would stretch its roots deeper to seek out water, and deeper soil takes longer to dry out anyway. I've found I do have to water that bed more often, and renew the nutrients in it every year. But the plants do great! Keep reading the posts and you'll see that my pumpkin bed has grown some outstanding pumpkins, zucchini and beans the past two years, and it was very cost and space efficient as well.

    2. Oh, okay. Carrots were actually the first thing that came to mind when I read that. This will be my first year with raised beds. I often mound the soil in my garden before I plant anything, but that's the extent of "raising" the soil that I've done. This will also be my first herb garden. I had some of the basic herbs last year, but I want to start some perennials this year. I'm thinking raised beds would be good for that. I have been reading your blog on and off all day. I love it! Keep up the good work! -Kim

    3. I would suggest saving your raised bed space for plants that need better nutrition. Most perennial herbs like rosemary, thyme, sage, and oregano are very sturdy. They can grow very large and don't require as much nutrition as more tender crops. As a general rule, you can stick these herbs into any rocky little nook you'd like and they will do fine. Just give them space, sunshine, and some water the first year you plant them or during major droughts. Perennial herbs are ridiculously hardy and if you have limited garden space it would be a waste to use the raised beds for them. I hope this is helpful!