Wednesday, March 2, 2016

farming by spreadsheet

I appreciate a sharp hoe as much as the next farmer, but when it comes down to it, one of the most valuable tools on my farm is the spreadsheet.

Most people are surprised when they hear how much planning goes into a farm season. Some farmers get by with a more seat-of-their-pants approach, but I firmly believe that if you want to ensure a successful farm season, and hopefully make a living at farming, you've got to crunch some numbers. (Nerd alert! Don't say you weren't warned.)

My farm season really begins the previous winter, when I sit down to jot some notes about what worked and what didn't in the past year. I look back at my offerings each week throughout the CSA. Were there weeks when I would have liked to offer members more choices? Were there production gaps for my most popular crops? Were there any varieties that produced a lot more or a lot less than I expected? I also survey my members to find out which crops they'd like more of, which ones they could do without, and which things they'd like to see me offer in the future. From all this information, I draft a new planting plan for the coming year.

Next, I go crop by crop and figure out how many times during the season I will grow each one (each planting is called a "succession") and how many bed feet of each succession I am likely to need. I figure that out based on calculating how many shares of each item I'd like to get, how many bed feet I'll need per share, and how long the crop can stay in the ground before it's over-mature.

For example, say I want to grow enough lettuce for everyone in the CSA to get one head per week for the entire season. Based on my spacing, I can get 3 heads of lettuce per bed foot. Since my beds are 160 feet long, that means I can get 480 heads of lettuce per bed. With 80 shares in my CSA, I could get 6 shares of lettuce per bed, or 6 weeks' worth of lettuce. However, I know that lettuce will not sit for 6 weeks without bolting (going to seed), so instead I might decide to plant a half-bed of lettuce every 3 weeks.

Once I've figured out which crops I'll be growing, the timing of each succession, and how many bed feet I'll need per succession, I have a general outline of my crop plan. I enter all of those crops, successions, and bed lengths into an online farm tool called AgSquared. Then I work on creating crop rotations: putting similar plant families together into 4-bed sections and placing them on a map of the farm. Crop rotation is one of the tools farmers use to make sure they're not overtaxing the soil on their farm. Good crop rotations can also help reduce pest and disease pressure on certain crops. Generally I try not to grow things from the same crop family in the same place on the farm more than once every 4 years.

I group my crops into 4-bed sections because 4 beds generally works out to be a good amount for a CSA of my size. When I'm mapping out my farm, if I find (for example) that I need to add a half-bed to fill out the short-season Roots and Greens section that will be planted on May 1, I look at my crop plans and decide which crop I would like more of. If I find that I've planned for one-third of a bed too many in the Solanaceous family (potatoes, tomatoes, peppers, eggplants, and tomatillos), I need to change my crop plans to reduce the number of plants so they fit into the section. Basically, a lot of fiddling with the crop plan happens during this step.

After I have my season planned and my farm mapped out, it's time to order the seeds! I download my seed order from AgSquared (my first spreadsheet for the season!). This spreadsheet tells me when I need to seed each crop and how many of each seed I will need. Now I have the fun task of choosing varieties. Although I have many favorites that I grow year after year, I also like to add a few new ones to the mix each year, to keep things interesting. I order most of my seeds from companies that sell seeds that are regionally adapted to our latitude and climate. Some of these companies are in the Northwest, while others are in New England. All of them feature new seed varieties every year, and it's fun to experiment.

Once I've chosen the varieties for the year and placed my seed orders, I enter the variety names in AgSquared. Now I have my season fully mapped out. I pull reports (more spreadsheets!) from AgSquared and download them to my computer. One spreadsheet is my propagation schedule, which means the plan for any crop that will be started in the greenhouse. Another spreadsheet is my transplant schedule, which is the plan for when the greenhouse plants will be planted out into the field. I also have a spreadsheet for the direct-seeded crops that will be seeded throughout the season. A final spreadsheet is the farm map itself, which shows in a visual form where and when each crop will be planted.

Click here if you want to see what this year's farm map looks like!

Once all these spreadsheets are downloaded and formatted the way I like them, I print them out and bring them to the farm. Now my crop planning is done and I'm ready to start the actual work of planting! Throughout the season, I update my spreadsheets with actual data (and create others, too, to track things like irrigation and harvest.) All of that information will help inform crop plans for future seasons. It's a cycle of constant tinkering and, hopefully, improvement that I couldn't do nearly as well without my trusty spreadsheets.


  1. I love seeing the crop map and learning how it comes together!

  2. this was a really nice entry. I am always curious how people set up their planting plan. the link to AgSquared was helpful. I wont be purchasing their product for just my tiny yard garden, but they offer free webinars on use of their product and that information has helped me put together my garden plan differently than in the past. Thanks and I look forward to eating some of those yummy plants!

    1. Glad it was helpful, Sara. Thanks for reading!