Last week we started work on a new greenhouse for our transplant “starts.” About half of the crops we grow we plant out into the field from starts that have spent their first 6-8 weeks in the temperate conditions inside our greenhouse (properly called a cold frame, because it is unheated). There are many advantages to using this technique. Because organic growers do not use the pre and post emergence herbicides that most conventional growers use when direct seeding, competition from weeds can be severe. By using transplants, we give our crops a real jump on the weeds that can make all of the difference. We also use fewer seeds when we transplant because we can plant starts out at the desired spacing in the field. Germination rates vary and a farmer needs to plant the seeds closer together in order to ensure a good stand when seeding directly into the field. When we direct seed, we generally need to go through the field and thin the seedlings once they emerge. (Greenhouse seeding doesn’t work for all crops, though. Carrots and other root vegetables don’t do well with transplanting because the roots get twisted or damaged. And things that are planted at high densities, like arugula and spinach, are simply too time consuming to transplant. These crops are always direct seeded into the field.)
These days it seems that most farms have moved to buying transplants in from large commercial greenhouses. But for us, growing all our own starts gives us the flexibility to do small frequent plantings, to try unusual varieties, and to experiment by doing small lots of different things. We also like to maintain as much control as possible over the growing process from the very beginning.
We set up our first greenhouse when we first started farming over 15 years ago, and added a second cold frame with a shadecloth covering as a hardening off area a few years later. Lately, we’ve been finding the greenhouse getting overcrowded at the busiest times of year, and have sometimes had to hold off on seeding until we were able to move things out into the field. The additional greenhouse we’re putting up now will nearly double our interior space, which will allow us to grow closer successions and larger plantings of many of our crops. It removes one more obstacle to better management of our planting schedule!
(yes, there is a cat on the ladder with Steve in the top picture)
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