As the nights draw in and the hedgerows are bright with the colours of autumn, the garden enters a new, slower phase of life. Plant growth becomes more gradual and we have time to reflect on the past year and make plans for 2019.
This year has been one of extremes – snow in spring followed by intense heat and drought. Not an easy year for growing vegetables and I know it’s led many UK growers to think more about climate change, extreme weather events, and what that means for their businesses.
Here at Trill, we address the problem by creating diversity in the garden. Diversity in the crops we grow, diversity in our fertility-building green manures and diversity in the seeds we sow. We grow more than 60 different vegetable crops over the course of the year, over 125 different varieties and have 8 different plant species in our green manures (most growers only use 1 or 2). All this means that we can offer a diversity of vegetables to feed our customers, a diversity of plants to feed our soil and what’s more, whatever the weather, something will grow well!
Our dedication to diversity also stretches to the seeds that we save and sow. The dry, warm summer was perfect for seed production and we harvested enormous seed crops of Golden chard and a parsnip called ‘Tender and True’ for The Real Seed Catalogue in Wales. Both these varieties are genetically diverse, open pollinated plants which ‘breed true’. This means that we can grow a number of plants of a variety, allow them to cross pollinate and we end up with offspring which are similar (but not identical) to the parent plants. Importantly, cross pollination maintains the genetic diversity in these varieties, ensuring that the crop has the means to adapt to future growing conditions. In the case of our Golden chard, this genetic variation is clear – the stems come in every shade of yellow from buttercup to mustard. With our ‘Tender and True’ parsnips, the differences are much more subtle, perhaps one is more resistant to canker, another might be more tolerant of drought.
Our chard and parsnip seed crops are just two of many crops we save seed from. All in all, we have around 40 varieties of 20 different crops in our seed stock which we have grown ourselves.
Before we save seed from a particular crop, we always choose the best examples of that variety to use for seed production. That way, each year we save seed, we’re choosing the plants that are best adapted to our growing conditions, our soil and our micro-climate. Eventually, we’ll end up with plants that are specifically adapted to our site. This process can take a little patience – biennial crops take 2 seasons before they flower and set seed - but experience shows that the quality of our homegrown seed outperforms the seed that we buy in, and so we continue.
(Senior Grower and Seed Production Coordinator, Trill Farm Garden)
Select strong healthy plants with characteristics that you are looking for. If it is an heirloom variety that you are saving, it is best to select the variety that best fits the description of the variety. If you want to select varieties that fruit earliest, then select the earliest fruiting each year.
Clearly label the plants that you have selected. Tomato plants generally do not cross with one another (they are in-breeders) so you can grow and save seed from more than one variety in one polytunnel.
Harvest and processing
Once the fruit is over-ripe for eating it will be ready for harvesting for seed. At this stage take all the ripe fruit off the plants, then slice them along their equator (use a bread knife for this as it is less likely to damage the seed). Then squeeze out the pulp into a container.
This can then be left for 3-4 days to ferment (this breaks down the germination-inhibitor that surrounds the seed). Do not leave for longer than for days as premature germination can occur. You may notice a mould appearing at the top of the pulp – this is fine and all part of the fermenting process.
Once fermentation is completed then poor the pulp/seed into a long necked container – something like a milk bottle works well. Fill it up to ¾ full and shake the bottle vigorously (with a lid on…). This helps to separate the seed from the pulp. As the seed starts to settle back down to the bottom of the bottle you can start to decant the pulp and water. A few small, light seeds may also come out. Decant until most of the water has left the bottle then repeat this process 5 or 6 times, or until the seed looks clean.
Fill up the bottle, now with clean seeds in, one last time and empty into a sieve. Blot the bottom of the sieve with kitchen towel to dry excess moisture and then turn out the seeds ideally onto a non-stick surface such as a plastic chopping board. Using the bottom of the sieve, spread out the seeds evenly to form one layer of seeds. As you are doing this you can have a bit of kitchen towel inside the sieve which will take away some of the moisture without the seeds sticking to the towel.
Label the seeds and put somewhere dry and airy to dry further. Once the seeds have dried they will peel off the chopping board in one piece. They can then be crumbled up into a paper seed packet and dried further using silica gel. To do this put the seed packet inside an airtight container and put the same amount of silica gel in the bottom of the container. Put a humidity reader into the container and close the lid. Leave until the relative humidity is around 50%. Then remove the silica gel and store the seeds in the airtight container somewhere cool and dry, and they should keep for up to 5 years. Don’t forget to clearly label the seed packet with the variety and the date.