I taught a class in late August on Planting for a Fall Harvest where I showed the students you don’t have to have a Greenhouse to extend the season. You can also have a cold frame or even simpler is what I call a low tunnel. Now with the cold nights, you definitely need something over your new fall transplants.
I like to make my low tunnels out of 2″ x 4″ fencing or even concrete reinforcement wire. I just open up the fence roll, cut off enough so it will be curved above my plants and turn it upside down on the soil.
Cover it with winter weight row cover (1.0 ml). I put rocks on mine to keep it from blowing away. Now you have a secure low tunnel that will protect your plants during the shoulder season that is closing in on us quickly. What is a shoulder season? It is the time of year when the temperatures can drop quickly at night near freezing and then heat up in the day. The temperature shifts can swing wildly during the shoulder season. We have a shoulder season in spring and fall. By making a low tunnel, you can extend the season and grow vegetables like spinach, arugula, kale, lettuce, bok choy, mustard, mesclun, radicchio and other cool season crops much later. Fall is a great time to plant cool season crops and it’s not too late if you get transplants now. It might be too late if you start from seed unless it’s lettuce. Try to pick varieties that are cold tolerant.