A 4 by 4 grid is 16 square feet. You have planted 16 of them, which comes to 78 plants. Your plan is saved in this browser and travels in the page address, so you can send the link to yourself.
“SFG method” is the per-square figure from Mel Bartholomew’s square foot gardening method, as listed by Cornell CALS. It assumes an intensive bed of amended soil, and it is a convention rather than an extension recommendation. Where that page does not name a crop, the planner falls back to the density its in-row spacing implies, which assumes conventional rows.
Spacing checked against Cornell Garden-Based Learning, University of Illinois Extension, University of Minnesota Extension. 2 of the 8 crops here have at least one figure no source could be found for: basil, kale. How this data is checked
Square foot gardening trades rows for a grid, and the arithmetic changes with it. Rather
than working out how many feet of row a crop needs, you decide how many one-foot squares
to give it, and the crop's density tells you how many plants that is.
This planner does that bookkeeping. Set a grid size, pick a crop, tap squares to plant
them, and the totals build underneath.
How to use it
Set the rows and columns. A four by four grid is the classic starting bed. Four
by eight matches a standard timber-framed raised bed.
Choose a crop to place. The dropdown shows each crop's density — how many go in a
square, or how many squares one plant needs.
Tap squares to plant them. Tapping a square that already holds the selected crop
clears it again.
Print the plan with the button at the bottom. Grid lines and labels print
legibly; the site furniture does not.
The plan is saved in your browser as you work, and also written into the page address,
so you can send the link to yourself to open on another device.
How it is calculated
There is no clever geometry here — it is bookkeeping, applied carefully:
plants = squares assigned x plants per square foot
The care is in what happens when that number is less than one. Crops such as zucchini,
winter squash and pumpkin have a density below 1, meaning they need several squares per
plant rather than several plants per square:
squares per plant = ceil(1 / plants per square foot)
For those crops the planner rounds down, and says so. Assign a zucchini one square and
it reports zero plants with a note explaining it needs about ten. Assign it ten and it
reports one. That is more useful than a cheerful "0.1 plants".
A worked example
A four by four grid, sixteen squares. Two squares of carrots, one of lettuce, one of
tomato:
Carrots: 2 squares x 16 per square = 32 plants
Lettuce: 1 square x 4 = 4 plants
Tomato: 1 square x 1 = 1 plant
Total: 37 plants in four squares, with twelve squares still free
Replace the tomato square with zucchini and the planner will tell you that one square is
not enough: at 0.11 plants per square, a zucchini wants around ten.
Plants per square foot
Crop
Per square
Crop
Per square
Carrot
16
Broccoli
1
Radish
16
Cabbage
1
Spinach
9
Cauliflower
1
Beet
9
Kale
1
Bush bean
9
Pepper
1
Onion
9
Tomato
1
Garlic
9
Eggplant
1
Cilantro
9
Okra
1
Pea
8
Potato
1 per 4 squares
Lettuce
4
Sweet potato
1 per 4 squares
Basil
4
Zucchini
1 per 10 squares
Parsley
4
Winter squash
1 per 10 squares
Strawberry
4
Watermelon
1 per 10 squares
Cucumber
2
Pumpkin
1 per 17 squares
Densities that come out as "1 per N squares" are the reciprocal of the published
plants-per-square-foot figure, rounded up to whole squares.
Tips and common mistakes
Put the sprawlers on the edge. A zucchini or a squash given its ten squares will
still spill over the frame. Planting it at the edge of the bed, facing out, saves the
plants next to it.
Trellis the climbers. Cucumbers, pole beans and peas cost almost no floor space when
they go up rather than out, which is what makes them good value in a small grid.
Do not plan every square for the whole season at once. Fast crops come and go two or
three times while a tomato occupies its square from May to October. Plan the early
round, then replan as squares empty.
Watch the shade. In the northern hemisphere, anything tall belongs on the north side
of the bed, or it will put the shorter crops in shadow from midsummer onwards.
Check the depth your crops want. A grid says nothing about depth, and carrots in a
six inch bed will fork and stunt. Deep-rooted crops want twelve inches of loose soil.
Common questions
What is square foot gardening?
A method of growing in a grid of one-foot squares rather than long rows, with each square planted at a density set by the crop — sixteen radishes in a square, one tomato across a square or more. It suits raised beds, removes the walking space rows need, and makes rotation and succession easy to track because each square is its own small plot.
How many plants go in a square foot?
It depends on the crop's mature size. Sixteen for radishes and carrots, nine for beets, spinach and bush beans, four for lettuce, basil and strawberries, one for kale, broccoli or a tomato. Sprawling crops work the other way round: a zucchini needs around nine squares per plant and a pumpkin closer to sixteen. The planner uses each crop's own density and tells you when a crop needs more squares than you have given it.
Is my plan saved?
Yes, in two places. It is saved in this browser's local storage, so it is still here next time you open the page on this device. It is also written into the page address, so copying the link and sending it to yourself carries the plan to another device. Nothing is sent to us — there is no account and no server holding your plan.
How deep does a square foot bed need to be?
Six inches is the classic minimum and works for shallow-rooted crops, provided the bed sits on open soil that roots can carry on into. Eight to twelve inches is more comfortable and covers most vegetables. If the bed is on a patio or a solid base, go to twelve inches, and deeper still for carrots and parsnips.
Why does the grid show letters rather than colours?
So the plan works in print, in greyscale and for readers who cannot distinguish particular colours. Each planted square carries an abbreviation of the crop name, and the table underneath gives the full list. A colour key would look prettier on screen and be useless on the printout you take to the garden.
Can I plant the same square twice in a season?
That is one of the method's advantages. As a fast crop such as radishes or lettuce comes out, the square is replanted immediately with something else. Keep separate plans for early, main and late season rather than trying to record all three in one grid, and use the planting date calculator to work out when each round goes in.