Yes! It’s not rocket science; I just calculate how much of what we need to have enough for a year. And how much space that takes in the garden.
At school I used to ask myself why we had to learn mathematics. Why learn to handle those complicated formulas about nothing!? Now that we’re living (more & more) self sufficient, I use maths almost on a daily basis! I use it for the bread baking formula (100% flour, 35% water, 35% milk, 4% fresh yeast and 1,8% salt) and to design the garden.
Enough garlic for freaks (I’m speaking about us now)
Garlic is an easy one to calculate because you can easily store it for a year if you treat it right*. Fresh vegetables are more difficult because they have to be ready at the right time.
How much do you plant when you really like garlic? When you make risotto with 1 whole bulb of garlic, or spinach pie with 6 cloves, or roasted paprika with a lot of roasted garlic, chicken in the oven with 30 cloves… 🙂
And to make it a bit more complicated: we have an average of 4 people at the table in winter and 8 people in summer, you can plant garlic in March & October and harvest in July or August.
Let’s see how much we have to plant in October in order to have enough in July and the rest of the year.
Garlic plants grow on 15×10 centimeter so you can grow up to 70 plants on a square meter. But with 35-40 plants per square meter you have better, bigger bulbs. You also get bigger bulbs with October planting.
I use around 3 bulbs of garlic a week in May-September (22 weeks), and 2 the rest of the year (30 weeks). So in October I have to plant (3×22)+(2×30)=126 cloves of garlic in order to get enough bulbs for a year. That’s 126/40 = around 3,5 square meter in the garden.
* More about garlic
How to harvest & store your garlic so you can keep it for a year? First you snip off the scapes in summer, as soon as they appear. Now all the grow-power will go into the bulb. (the young scapes are edible! Nice in salads, soups etc.)
Harvest garlic bulbs when the lower five leaves of the plant have turned brown. If you wait too long, the cloves within the bulb begin to seperate. Bulbs with seperated cloves don’t store as well.
Let them dry in a shady, windy place to form their protection peel. That takes up to 2 or 3 weeks. When they are dry, you cut of the top leaves and store your garlic in boxes in a cool and dry place. Now you can keep them for a year!
Back to maths
So in order to have enough garlic for a year, I need to plant 126 cloves on 3,5 square meters in October. But what to do with all the other square meters in the garden?
We love Brussels sprouts, but we don’t like to eat them 3 times a week. In winter you cannot sow something extra for harvesting 6 weeks later so winter vegetables have to be planned carefully.
We sow sprouts from March until May and harvest them between December and March. That’s around 16 weeks in which we eat them weekly. One plant usually gives more than one meal, but let’s be on the safe side and say we need 16 plants. So I sow 2 or 3 seeds every 2 weeks in spring.
The plants need 60 cm space and if I plant them in a bed that’s 3 meters long and almost 2 meters wide, I manage to get them all in there.
We can harvest our kale from September until May. That’s 9 months, or 35 weeks. In which we can eat kale once a week (in a stew or as kale chips). We harvest a lot from one plant and the plant even grows better when you harvest the outer leaves regularly. But let’s not be optimistic and say we can harvest twice from one plant. So we need 18 kale plants.
I start sowing kale from the end of March (a few weeks before the last date of frost) until the end of May. That’s about 10 weeks and when I sow with a 2 weeks interval, I sow 4 seeds at a time.
So now you get an idea of how to calculate for what you need. But you can’t really predict what you will get because of the big unreliable factor NATURE. Your soil, your seeds, your effort, your compost, the weather… When it rains a lot, some crops will grow like crazy (green leavy things) and others can go bad (garlic, onions, pumpkins). Or when it’s too dry, your greens will not grow well but onions and purslane will be fine.
So don’t rely too much on your calculations & use common sense!
You spread your risk with sowing with an interval, always sowing a few extra seeds, trading seedlings with neighbours, with mulching and with being flexible. And of course you can store more of what keeps well, like (butternut) pumpkins or dried beans, for when something goes wrong with your crop.
To get an idea of the needs of a family in a year, you can ask me for our annual family food planning in a spreadsheet. Send me an e-mail.