This is the second part of a series on crop planning for seed production. Seed production planning part 1 covered growing small trials to evaluate whether a variety was worth growing to seed on your farm in your climate.
Once you’ve decided the varieties for this year’s seed production, you need to determine how much seed you would like to harvest.
GROWING SEED FOR MULTIPLE YEARS
Under good storage conditions most seed will last a number of years. You can grow enough in one year to cover your seed needs for multiple years. This has a few benefits:
- Growing fewer varieties gives you more space for better isolation distances to avoid cross-pollination.
- Growing a larger number of plants of on variety provides more plants to observe and you can better select the most fit individuals. Large population also maintain a broader genetic pool that ensures more resilient varieties.
- Cleaning bigger seed lots is easier than cleaning small seed lots.
For most varieties, I aim to grow enough seed for at least a 3-year supply. (This is not possible for all varieties. I.e. parsnip, leeks and onions lose germination quickly after a year in storage.)
(You can read a previous post about isolation distances and population sizes.)
HOW MUCH SEED DO YOU NEED?
Consider all the ways you sell or use seed, and estimate the needs for each use. This includes
- Seed you use on-farm. This is calculated from your crop plan – basically the rowfoot you plan to grow multiplied by a seeding rate. (The crop planning for organic vegetable growers handbook covers this.)
- Seed sold through a seed catalog (in packets or in bulk). This is projected from the previous year’s sales records.
- Seed sold to other seed companies. This is based on how much seed they need.
Then make a chart to summarize this information. Here are two examples loosely based on our farm.
EXAMPLE 1 – TATSOI SEED NEEDS
Tatsoi is a leafy green from the Brassica rapa species.
At Tourne-Sol farm, we seed a lot of Tatsoi to sell bunching or as part of our salad mixes. We also sell Tatsoi seed as packets to gardeners and in bulk quantities to other farmers. And our seed company clients purchase regular amounts of our Tatsoi seed.
|Packet Sales||100g(50pkts x 2g)||120g(60pkts x 2g)||140g(70pkts x 2g)||
|For Other Seed Companies||1kg||1kg||1kg||
We’ll need to harvest about 7 kg of Tatsoi seed to meet our projections for the next 3 years.
EXAMPLE 2 – JAUNE FLAMMÉE TOMATO SEED NEEDS
We need significantly less tomato seeds than Tatsoi seeds. Since we transplant tomatoes, our on-farm needs are low and we only sell packets through our seed catalog. Our seed company clients purchase a significant volume but they usually buy enough seed for multiple years at once.
|Packet Sales||5g(50pkts x 0.1g)||6g(60pkts x 0.1g)||7g(70pkts x 0.1g)||
|For Other Seed Companies||300g||
We’ll need to harvest 321 g of Jaune Flammée tomato seed to meet our projections.
In our next seed production planning installment we’ll figure out how many plants to grow to meet these seed needs.
6 thoughts on “Seed Production Planning Part 2 – Calculating Seed Needs”
This has some useful info on small-scale organic seed production – http://goo.gl/V6NYt
Patrick Steiner’s small scale organic seed production is a great reference.
I’ll actually be referencing in my next post when I talk about seed yields.
Do you have any other favorite seed books?
Norman Denoâ€™s self-published Seed Germination & Practice available at http://search.nal.usda.gov/nalsearch/result-list/fullRecord:deno/#ResultList=0|0|_|RANK|2%2C0
Plant Propagation by Alan Toogood – http://www.amazon.com/American-Horticultural-Society-Propagation-Plant/dp/0789441160/ref=cm_cr_pr_product_top/183-3604330-7369437
A lot of those books are on my favorites list too.
I am curious to read Norman Deno’s Seed Germination and Practice.
Thanks for the suggestions.