Space and time are a cost line
Container, media, liner and labour all arrive with an invoice, so they get counted. Ground does not. It shows up as rent, or as a mortgage, or as nothing at all if the land was inherited, and the result is that crops which sit for a long time on a lot of ground look cheaper than they are.
The unit that fixes this is the square foot week. Multiply the ground a plant occupies by the weeks it occupies it, and you have a quantity you can put a price on. On the figures the form opens with, 1.18 square feet for 26 weeks is 30.68 square foot weeks per plant, and at two cents each that is 61 cents. The container is 85 cents. The ground is 72 percent of what the pot costs, and unlike the pot it does not appear anywhere in the accounts as a crop cost.
| Line | Run of 10,000 | Share |
|---|---|---|
| Containers | $8,500.00 | 25% |
| Media | $6,512.00 | 19.1% |
| Liners, cuttings or seed | $5,500.00 | 16.2% |
| Labour | $5,866.67 | 17.2% |
| Ground, by the square foot week | $6,136.00 | 18% |
| Everything else | $1,500.00 | 4.4% |
| Total | $34,014.67 | 99.9% |
Because it is a rate multiplied by time, the space line is also the one that responds to schedule. Four weeks off the run at these numbers is $944 on a $34,015 crop — nearly three percent of the whole cost, for nothing but finishing sooner.
The survivors carry everything
A plant that dies in week nine has already had its container, its media, its handling and nine weeks of ground. None of that comes back. Every cost in the run has to be recovered from the plants that actually leave the yard, which means the cost per saleable plant is the cost per plant started divided by the saleable share.
On the defaults that is $3.40 per plant started against $4.86 per saleable plant — the losses add 42.9 percent to everything. That multiplier is unforgiving as the share drops. At 90 percent saleable the loading is 11.2 percent. At 70 percent it is 42.9 percent. At 50 percent it is 100 percent, and every plant you sell is carrying a dead one on its back.
| Saleable share | Loading added | Cost per saleable plant |
|---|---|---|
| 95% | +5.3% | $3.58 |
| 85% | +17.6% | $4.00 |
| 70% | +42.9% | $4.86 |
| 55% | +81.8% | $6.18 |
The practical consequence is that a point of grade-out is worth more than a point off almost any input price, and it is worth measuring properly rather than estimating. If you have per-stage figures, the potting-up stage calculator will compound them into an overall share and give you the media volume and ground area to bring back here.
Getting the cost per square foot week
There is no standard figure and this page states none. Build it from your own books. Take everything it costs to run the growing area for a year that does not already sit on a specific crop — land or rent, structures and their cover, irrigation and its power, the general overhead — and divide by the square feet of growing ground and then by 52. Two operations on the same road will land on very different numbers depending on what they own and what they carry.
The number matters more than it looks, because it is the only cost on the page that scales with time. Everything else is a per-plant charge that happens once. If your crops sit for two seasons rather than one, this is the line that doubles.
What is not in here
Selling costs, delivery, breakage after grading, returns, and any margin at all are outside the calculation. The break-even figure is the cost of standing the plant on your own ground and nothing more. Overhead that belongs to the office rather than the growing area is not in the square foot week rate unless you put it there, and you should decide deliberately which of those two places it lives in so it is not counted twice.
No price on this page comes from anywhere but your own form. There are no market rates here, no supplier prices and no wage figures. For turning a measured production rate into crew hours and crew days rather than minutes per plant, the crew productivity calculator does that arithmetic properly. For the markup arithmetic on top of a cost, job cost and markup handles the margin-versus-markup trap. And the ground figure this page prices comes out of the overwintering space calculator if the crop spends part of its life under cover.
Questions people ask
Why divide by the saleable count rather than adding a shrink percentage to the cost?
They are different arithmetic and only one is right. Adding 30 percent to a $3.40 cost gives $4.42. Dividing $3.40 by 0.70 gives $4.86. The second is correct, because the cost of the whole run has to be recovered from the plants that sell, and 7,000 plants have to carry $34,015. It is the same trap as the difference between margin and markup, and it gets worse as the loss share rises: at 50 percent saleable the two methods differ by a third.
What should the cost per square foot per week be?
Your own number, and there is no standard one. Take what running your growing area costs for a year — land or rent, structures, cover, irrigation and its power, general overhead that is not already on a specific crop — divide by the square feet of growing ground, then by 52. Two cents in the form is a placeholder to make the arithmetic visible and nothing else. An operation with a heated glasshouse and one with an outdoor gravel pad will differ by an order of magnitude.
Do the per-plant figures multiply back to the run total exactly?
Not quite, and the page says so. Each cost line is computed as a whole number of cents for the entire run, so the breakdown sums to the total exactly with no reconciling adjustment. The per-plant figures are then rounded once from that total, so multiplying $4.86 by 7,000 gives $34,020 rather than $34,014.67. The run figures are the exact ones; the per-plant ones are the run divided and rounded to the cent.
How do I handle a crop that steps through several container sizes?
Add them together before they come in here. The container cost is the total of every pot the plant ever sits in, the media volume is the sum across all stages, the labour is all the handling, and the ground per plant is a weighted average across the run. The stage calculator produces the media total and the square foot weeks directly, and dividing its square foot weeks by the weeks held gives you an average ground figure that is consistent with the rest.
Should the cost of my own stock block go into the liner cost?
Yes, if you want the run costed honestly. Cuttings from your own stock block are not free — the block occupies ground, takes labour to maintain and to harvest, and produces nothing saleable. Work out what it costs to run the block for a season, divide by the usable cuttings it yields, and put that in the liner field. The stock plant calculator gives you the yield side of that division and the block area to price.