Last Thursday (9/25/14), our friends at Turtle Tree Seed led a field day of their seed-production farm and seed company based at Camphill Village-Copake. About 30 individuals contribute to the management of the gardens, the harvesting and processing of mature plants to extract seed, the cleaning and sorting of seed, and the marketing and packaging of the final product. Many of these individuals are residents of Camphill Village who have developmental disabilities, who have meaningful and fulfilling work thanks to the connection between Biodynamic Agriculture and the Camphill Village philosophy. The growers explained that to grow biodynamic seed, one simply grows the plants biodynamically (and organic seed comes from certified organic farms and plants). Because of the length of time in the field (seed crops are generally harvested well beyond eating ripeness), any plant grown for seed will face much more disease and pest pressure; this is why organic and biodynamic seed production is so important for environmental health, and why all growers should consider supporting only organic and biodynamic seeds; conventionally-produced seeds have a heavy impact on the environment before they are even planted by a farmer or gardener because pests, disease, weeds and soil fertility can all be managed through chemical methods. No matter the production philosophy or certification, one needs to isolate plant varieties in time and space if they are a crop that is likely to cross-pollinate (and therefore change the genetics of the seed produced). Additionally, plants that are grown for seed also need much more room because they will grow much larger.
The group learned three different seed extraction methods: dry harvest, wet harvest, and fermentation/wet harvest. Each technique involves taking the plant with fully mature seeds and separating the seeds from the rest of the plant, and cleaning out any immature seeds, making use of seed weight and seed size to help in the separation. For dry-harvested seeds (where the plant has flowered and created a pod that dries out), one uses significant pressure to crush and break down the pod and plant parts, then winnows with air to separate off lighter-weight plant parts and debris, and finally passes the seed through a set of screens to filter out larger particles and long bits of stem.
For wet-harvested seeds (where the plant’s fleshy parts contain the mature seed), one has to open the fruit and remove the flesh and seeds. In the case of cucumbers and tomatoes, the seeds are left to ferment for several days to break down a protective membrane around the seeds. The seed saver uses a water winnowing technique for wet-harvested seeds. Seeds and flesh are placed in a jar or bowl, and water runs on top. Then water is poured off, and with it goes the non-useable part of the mixture, which floats to the top, and the heavy, mature seeds stay at the bottom. After water winnowing, the seeds are spread on paper to dry.
We learned how variety selection works in root crops, which take two seasons to set seed. At Turtle Tree, the growers harvest mature (eating-stage) onions, carrots, etc. and sort them based on the varieties’ written descriptions. The 25% that most exemplify healthy, true-to-type specimens will be grown for seed that becomes the future seed stock on the farm. This helps ensure a purity in the variety for the long-term. The middle 50% of the crop will be replanted in the second season, and its seed will become what is harvested for sale through the Turtle Tree Seed Company. This is still a high-quality and true-to-type seed! The bottom 25% of the crop (they do not exemplify the variety characteristics as well as the top 75%) is used as food in the community dining hall. To account for differences in growing conditions, plants are harvested in very small batches and compared within their batch (then added to the graded piles). That way, the grower can control for the fact that poor soil in that few feet of the garden bed impacted the shape and size of the carrots, for example.
While not every one of us will become seed farmers, it’s important to support the work of the companies who are preserving the range of plants and subtly-different varieties. It takes more land and plenty of extra vigilance on the part of the grower, especially if the plants are being grown organically! Here are a few other seed companies we know and love (and who have taught us about seed farming in the past):
- Organic Seed Alliance
- NOVIC: Northern Organic Vegetable Improvement Collaborative
- Breeding Organic Vegetables: A Step-by-Step Guide for Organic Growers by NOFA-NY ($15 on Amazon, or free to download
- The Organic Seed Grower
- Pollination and plant genetics basics from Native Seeds/SEARCH
- Biodynamic Association