Weeks buy ground, units do not
Put the default list next to itself and the point is hard to miss. Salad mix appears eighteen weeks at one bag a share; zucchini appears seven weeks at three fruit a share. The zucchini looks like the bigger commitment when you are packing the box, and it is — three things in the bag instead of one. But eighteen bags at 0.55 bags a bed foot needs 32.7 bed feet per share, and twenty-one zucchini at 2.2 a bed foot needs 9.5. The salad takes more than three times the ground.
That ratio is the whole crop plan. A crop that shows up week after week is a standing order on your beds, and the way to shrink it is to shorten the season it covers, not to put less in the bag. Cutting a bag of salad from every box in the shoulder weeks frees more ground than dropping a whole summer crop.
Whole beds cost more than the arithmetic
The exact figure at the defaults is a little over 4,229 bed feet, which is 42.3 beds of 100 feet. Give each crop its own beds and it becomes 44, because five crops each round up. That is roughly 170 bed feet of rounding, and it is real ground that gets prepared, irrigated and weeded.
Shorter beds round tighter. If your ground allows 50 foot beds instead of 100 foot beds, the same plan rounds to a smaller total, at the cost of more ends to turn at and more drip line to connect. Whether that trade is worth making is a question about your equipment and your soil, and the calculator will show you the size of it either way.
The marginal share is the number to quote
Signing ten more members at the default list costs about 1,057 more bed feet — 10.6 more beds, which rounds to 5,500 square feet with the paths counted. That is the honest answer to "can we take a few more", and it is a different question from whether the money works, because the ground has to exist before the first box goes out.
| Crop | Weeks | Units a share gets | Units per bed foot | Bed ft per share |
|---|---|---|---|---|
| Salad mix | 18 | 18 | 0.55 | 39.3 |
| Head lettuce | 12 | 24 | 1.1 | 26.2 |
| Slicing tomatoes | 8 | 16 | 0.9 | 21.3 |
| Zucchini | 7 | 21 | 2.2 | 11.5 |
| Carrots | 10 | 10 | 1.6 | 7.5 |
The bed feet per share column above includes the 20 percent added for culls, which is why it is higher than the raw division.
Where this hands off
The calendar side of the same plan belongs to the succession planting interval calculator, which turns a supply period into a number of sowings and the days between them. The week when every crop lands at once is the input to the market harvest pick list calculator, and what the members pay and when is handled by the CSA share price drawdown calculator. For the ground itself — beds, cover, irrigation — see the hoop house sizing calculator and the drip emitter calculator.
Questions people ask
What should I put for units per bed foot?
Whatever your own beds have actually given you, for the whole life of that planting rather than a single pick. If you have no records, the extension service in your state publishes regional figures for common crops and is the right place to start, but treat anything published as a wide range rather than a number. The reason this is a field and not a constant is that the honest spread between a good bed and a poor one is large enough that a built-in figure would give an answer with no useful precision.
Does this account for a bed growing two crops in a season?
No, and that is deliberate. The page counts ground once per crop, so a bed that carries an early planting and then a later one is counted twice here. If you double-crop, the practical approach is to run the list, then pair up the crops that can share a bed and subtract by hand. The succession calculator will show you whether the two plantings actually fit end to end in your season.
Why does the whole-bed total not match the bed foot total?
Because each crop rounds up to a whole bed on its own. A crop needing 853 bed feet takes nine 100 foot beds, not 8.53 of them, and the leftover 47 feet is not usable by another crop unless you are willing to split beds. The page shows both figures so you can see how much of your ground the rounding is taking. Shorter beds make that number smaller.
How big should a share be?
That is a decision about your market, your costs and what you can reliably grow, and this page has no opinion on it. What it does is turn whatever share you describe into the ground it needs, so you can compare a heavy box against a light one in bed feet rather than in feeling. Members and other growers in your area are a better guide to the size question than any calculator.
Does the calculator say whether the numbers work financially?
No. It converts a share description into bed feet, beds and square feet, and stops there. Whether a given share count, share price and cost structure adds up is a separate calculation and depends on things this page never asks about — your land cost, your labour, your equipment and what you are paying yourself. The drawdown calculator handles the money timing side, and it does not issue a verdict either.