This week I was asked this question. I think it's a good question so I'm answering it here on the website.
I love what you do and love the fresh produce. Love the salad in the spring and have totally converted to Kale and Mustard greens and all the greens. I'm wondering though if in the fall you can go back to some of those cold vegetables? ...Can you grow zuchinni?"
Yes, it is possible to grow your favorite greens again later in the fall in a greenhouse. Allow me to elaborate. To grow a fall crop of greens, it is necessary to delay planting further into the season when the hotter day-time temperatures are passed, so the young plantings won't automatically bolt. (Cold weather crops "bolt", or "go to seed" when the weather is too warm.) However, with cooler day-time temperatures comes much colder night-time temperatures, often freezing temperatures. Freezing temperatures can do much damage to crops, including stunt their growth, complicate harvesting efforts, and make the end product less desirable. Of course these problems could be easier to control if the crop was grown in a greenhouse.
Here lies the problem. Here at EverGreen Farm all of our greenhouse space is dedicated to growing an abundance of wonderful heat loving crops like cucumbers, green beans, tomatoes, basil, and peppers. There simply isn't enough space or a long enough season to start another indoor fall crop sufficient to supply our farm memberships. Another thing to consider is that Fall is when we are concentrating our efforts on planting garlic and harvesting our crops of sweet carrots, beets, leeks, onions, potatoes, etc.
Now about zucchini. It is very sensitive to the cold. We start the seeds inside and as early as possible. The seedlings are then planted outside and protected with insulating row covers. As quickly as it grows, we pick the fruit and will continue to harvest until the very latest date possible. Once it freezes, we have to throw all the frozen squash and zucchini to the pigs. The only way to extend the zucchini/squash season is to grow them in a greenhouse. However, these plants are so big and take up so much room that this option would not be cost effective.
The more years we farm, we have come to find value in the saying "Everything in it's own season".
note - this answer is completely specific to the growing conditions at
EverGreen farm, and also based on our gardening experiences over the