Crop Planning for Organic Vegetable Growers with Dan Brisebois – Part 4 of 5

After the initial planning for financial targets comes the field planning—crop choice, planting schedules, crop maps, and, finally, filling out seed orders for each crop. 

Crop Planning Step 3: Make Field Planting Schedules 

Two things to consider in this step are when and how much to plant. 

When to plant. This is calculated by subtracting the days to maturity from your target harvest date: harvest date − days to maturity = planting date. For example, June 30 – 28 days = June 2. 

When considering crops’ dates to maturity, pay attention to whether the catalogue lists these dates from seeding or from transplanting. Also make sure to note the climate requirements (USDA zones). This is especially important when planting several varieties of one crop. 

How much to plant. Dan calculates this as follows: ((harvest yield x safety factor) yield) rows per bed = bed length. The safety factor is the percentage of extra crops. Dan uses a 30 percent safety factor on most crops. For example, for lettuce: ((50 heads x 1.3) 1 head/row ft.) 3 rows/bed = 22 bed feet. 

Crop Planning Step 4: Create Crop Maps 

Tourne-Sol’s land is divided into 17 blocks. Each block is a half-acre with 14 beds, each of which is 5 x 300 feet. A 300-foot bed is a good length for tractors. Beds are uniform in size, allowing tools and equipment to be standardized. This prevents the trouble of scrambling around looking for “the right size.” Your crop maps should be designed with tools in mind. 

Crop Planning Step 5: Choosing Vegetable Varieties 

Context is very important in your crop choice: geographical location, climate, humidity, and amount of daylight all affect what crop varieties you’ll have the most success growing (unless you’re growing everything in greenhouses). Looking at crop profitability is also a good way to choose crops. 

Choosing crops for a developing market. You can try observing what other farmers in the area are selling. But ultimately, you’ll only know what will and won’t sell when you bring your veg to market and people start buying it. So start with a plan, grow it out, and observe your first couple of markets. 

Choosing vegetables for CSAs and wholesalers. As opposed to guessing and diversifying—as when selling at farmers’ markets—you should be growing and harvesting according to your order when you’re selling to wholesalers. CSAs are less of an issue—choose varieties that you know the average CSA customer will enjoy.

Succession cropping. When planning out successions, two things to consider are dates to maturity and crop residue—how much plant material is left in the ground after harvesting. 

For example, arugula won’t be in the bed very long if it’s harvested as baby arugula, after which you can plant directly back into the bed. On the other hand, corn leaves a lot of plant residue both aboveground in the form of stalks and below in the form of root balls. You’ll need to plow to remove the residue before planting again. 

Another thing to consider when planning succession crops is seasonality, as some crops may mature slower while they’re out of season. 

Crop Planning Step 6: Generate Greenhouse Schedules 

This is fairly similar to coming up with a field planting schedule. Dan uses this equation: field date – days in the greenhouse = greenhouse date. For example, June 28 – 8 days = June 20. 

As for how much to plant, Dan uses this equation: bed length x rows per bed ÷ spacing x safety factor ÷ tray size = # of trays. For example, 15 ft. x  3 rows per bed ÷ 1 ft x 1.3 ÷ 72 cells per tray = 0.8125 trays.

Crop Planning Step 7: Fill Out a Seed Order 

Before you fill out a seed order, you need to figure out how much seed you need. This warrants another equation. For direct-seeded crops, compute the following:

bed length x rows per bed x seed rate x safety factor = seeds needed

For example, for Early Wonder beets: 165 ft. x 3 rows per bed x 16 seeds per row ft. x 1.3 = 10,296 seeds.

After you determine how many seeds you need, check if the supplier you’re buying seeds from sells them by seed count or by weight. If they sell by weight, you’ll need to convert the number of seeds into their respective weights as listed in the catalogues. 

Sample computations for conversion are as follows: 

  a. Seeds needed ÷ seeds per gram = grams needed
For example, 10,296 seeds ÷ 55 seeds/gram = 187.2 grams
b. Grams needed ÷ 28 g/oz = ounces needed
187.2 g 28 g/oz = 6.69 oz
c. Ounces needed ÷ 16 oz/lb = pounds needed
6.69 oz ÷ 16 oz/lb = 0.42 lbs

After crop selection, planting schedules, and seed orders are sorted out, there’s only one thing left to do: follow through with your crop plan. 

Next time, in our final post on the 11 steps of crop planning, we’ll examine those final steps—from executing the crop plan to planning for the coming year.

Watch Dan’s presentation on Crop Planning for Organic Production.

You can learn more by checking out our podcast with grower Dan Brisebois. 

And you can find all our market gardening podcasts at Farm Small, Farm Smart—the longest-running podcast on market gardening in the world.

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