Square Foot Gardening

Now that Linda posted the lovely photo of our pea blossoms, it's time that Rob and I make good on our promise to write a bit about the method we're experimenting with this year: Square Foot Gardening.

The basics:
1) raised beds -- significantly diminishes weeding and prevents walking on soil (crushing roots)
2) super fluffy, super-nutritious, moisture-regulating soil mix: 1/3 peat moss, 1/3 compost, 1/3 vermiculite.
3) handy 1 ft square grid: makes it easy to eyeball plant spacing and gives a
structure for interplanting of companion crops.

Why
SFG, popularized by Mel Bartholemew, is just one of many intensive gardening techniques. We chose it because my brother --- who really knows how to stretch a dollar --- had great success with this method in the past few years.

My brother had chosen this method for a couple reasons:

1) At the time, he was homeschooling 3 children. Several components of SFG make nice curriculum supplements: lots of measuring and calculations required in the bed construction and square-marking; plant life cycle; where food comes from; and all those soft lessons like delayed gratification, responsibility, and frugality.

2) My brother's the type of person who likes to optimize things from first principles. As such, I'm sure that he did extensive research on intercropping (interplanting of crops that have complementary nutrient needs/supplies) and optimal layout for succession planting (full 3 season gardening where each crop is turned under and supplies nutrients to the next crop). Roberto and I have not really pursued this thread --- while it's tempting to suggest that our incomprehensible layout must be the result of advanced understanding of soil conditioning and detailed planning, it's actually just haphazard (although mesclun-under-tomatoes does seem to be working out pretty well right now....we plan to pull the lettuces after their next bolt).

3) My brother really knows how to stretch a dollar.

Our experience so far

We built our Soviet block apartment complex, I mean, raised beds, in early March.

We learned that garden stores & home improvement stores don't really start stocking soil & supplies until LATE March. Getting the vermiculite and peat moss that early was a bit of a problem. I'd recommend building up your beds in the fall, so that you've got everything ready to go for putting that first pea seed in the ground on St. Patrick's day. Also, major home improvement box stores (who shall remain nameless) no longer carry vermiculate because, when dry, it poses a particulate inhalation hazard. (classified as a "nuisance dust" according to materials safety data sheets. Note that much of the recent flap over potential vermiculite hazard has been because of asbestos contamination, not a toxicity inherent of vermiculate.)

Since this was our first year doing SFG, our soil mix was a bit warmer than the ambient soil at the time, which was a plus. Unfortunately, germination was a bit dodgy for a couple reasons: first, the soil mix was so fluffy that the top inch dried out immediately on any sunny day. In general, this soil mix is really good at maintaining even moisture content (the vermiculite acts as a moisture capacitor), but only below the top layer (which is perfect once roots are established). Secondly, the water hookup at Squirrel Brand Community Garden was not turned on until late April, so we had to schlepp water from our home (only ~4 blocks away) every couple days to keep our germinating seeds moist.

We developed a greater appreciation for floating row covers at about the same time that everyone else in the country decided to start planning their garden --- way too late. So, in April, the heirloom seed supply that gave us such prompt service in February when made our initial order, was completely overwhelmed. So our row covers arrived a bit too for us to really take advantage of.

Which brings us to my second piece of advice: plan your garden early and order your seeds on-line by February. This will let you really engage in 3-season gardening to make the most of your community plot. In Cambridge, our last-frost-date is around the 3rd or 4th week of April. This means that the earliest crops (english peas & spinach seeds planted 6-8 weeks before last frost, onion sets or seeds planted 4-6 weeks before last frost) can go in as soon as the soil thaws --- first or second week of March! Also, February-March is the perfect time to start seeds for warmer weather crops indoors (if you have a sunny windowsill).

Our local stores don't stock seeds until April, which is really too late to get started. So order your seeds early, and you'll be ready to go for both direct-sow and indoor starts.