“I sure am glad that is over!” I’d say about vegetable gardening at this time of year. After dealing with diseases, insects, too much water, too little water, and lots of weeds, I was happy to remove any remaining vegetables, take soil samples for testing, sow a cover crop, and put my garden to bed.
Now I am pleased to pick and eat fresh greens from the garden into winter when temperatures drop below freezing! In the colder months in USDA plant hardiness Zones 6 and 7, you can grow arugula, collards, green onions, kale, leaf lettuce, mustard greens, pak choi, radishes, and spinach. The trick to extending the growing season is to protect your plants from cold. We’ll review two frost protection methods.
A cold frame is a box with a clear plastic or glass lid that acts as a miniature greenhouse. The use of a well-constructed cold frame can extend the growing season through the fall and into the winter. It is generally used away from the garden as it tends to be permanent once finished.
Uses. A cold frame is very versatile and can be used for hardening off plants, starting plants from seed, and for growing the cold tolerant plants.
Construction. Building a cold frame does not require an extensive knowledge of construction and is a fun activity for the whole family to participate in. The good thing about building one is that once you have accomplished it, with just a little yearly maintenance you don’t have to do it again. Most cold frames are constructed of wood and the top can be a repurposed window that has been removed from a house.
Cautions. Be sure to always have a way to open the cold frame’s top and keep it open, as temperatures inside the cold frame even during the winter can increase to the point where they will harm the plants.
Use temporary row covers directly in the garden to extend the growing season. Following installation, most row cover arrangements resemble long tunnels covering the plants. They require regular maintenance and attention in order to perform properly.
Structures for supporting the covers. Construct these from a variety of materials, including ½ inch PVC water pipe, metal fence posts, or repurposed wood. They must have some mechanism for opening, both as a means to facilitate harvesting the plants and to allow for air circulation in response to rising internal temperatures.
Cover materials. “Remay” or “Agribon” are examples of the material used to cover these structures These fabrics weigh 1.5 to 2.2 ounces per square yard, are designed to provide 70% light penetration, protect down to temperatures of 28 degrees (F), and allow rain and overhead irrigation to pass through. NOTE: These materials differ from floating row covers used to protect against insect infestations, which are lighter in weight (around 0.5 oz. per square yard), allow up to 95% light penetration, and do NOT provide protection below freezing.
No matter how you choose to extend your gardening season, I believe you will find it rewarding, educational, and a way to keep that good feeling that comes from getting your hands dirty well into the fall and winter.
Article written by Bob Wardwell, Extension Master GardenerSM Volunteer.
For more information
How to Construct a Cold Frame or Hotbed
by Cynthia Haynes and Richard Jauron
Iowa State University
Floating Row Cover
by Jon Traunfeld
University of Maryland Extension Specialist
Western North Carolina Planting Calendar for Annual Vegetables, Fruits, and Herbs
by NC State Extension Publications