It may seem as though gardening season is nearing its end but with a little extra planning it is possible to keep growing some hearty greens and root crops growing into December. Cold season greens are packed with vitamins and can help you stay healthy through the dark Winter months. Not to mention, many Fall crops will sweeten as the weather turns cold! Farmers extend their growing seasons with high tunnels, low tunnels, and heated greenhouses but even in your own garden you can enjoy a long harvest. Here are a couple ways:
Row cover
Row cover is a fabric, usually made of lightweight polyester or polypropylene, that allows sunlight, water, and airflow in but keeps unwanted factors like insects, excessive sunlight, or frost out. It’s easy to find and not too much harder to work with. You can order it online from most garden/seed suppliers. You can also find metal “hoops” online or fashion some yourself to act as a frame to drape the fabric over without damaging delicate plants. Fabric edges should be secured with staples or rocks to the ground to keep the fabric from blowing away or letting in unwanted bugs or cold temperatures.
Different weights of fabric are used differently.
The lightest weight fabrics will let in up to 85% of sunlight and are mostly used to keep pests out of veggie beds.
Mid-weight row cover will let in about 75% of sunlight making them a good shade cover for early season greens that you want to grow into the Summer. This weight will also offer some frost protection, but heavier weights can protect crops down to 25 degrees!
Heavy weight row cover is ideal for extending the growing season into late Fall and early Spring, as well as providing extra protection for overwintering crops and perennials. This weight provides the most protection against the cold but may limit sunlight to 60% or less.
To use row cover as a season extender in the Fall it’s best to set it up before the first frost to trap as much warmth in the soil as possible. Once temperature lows are consistently below 25 degrees, the row cover has done its job and it may finally be time to call it quits, although row cover can also be used on early Spring seeds and seedlings to give them a few weeks head start!
Row cover at our St. Paul’s School garden, used here to prevent cabbage loopers
Pest free Brassicas!
Cold Frames
Cold frames are a great, more permanent option for extending your growing season. Cold frames are structures, usually made from a frame with a transparent top and sides, that act as miniature greenhouses. They can be placed over existing beds and can also be used to store plants in containers or to start seedlings in trays.
Here at Edible Eden we build large cold frames out of treated lumber and polycarbonate. We are currently developing a lighter more economical model that will fit securely over our raised beds.
Some pros and cons:
Cost - cold frames are a substantial investment and prices for generic frames usually begin at $200 a bed. Meanwhile row covers can be purchased online for around $50.
Maintenance - While cold frames and row covers both trap heat, cold frames will not allow the same level of airflow as row covers. For this reason, it’s important to monitor the temperature and humidity levels within the frame. Most standard cold frames, including our custom designs, allow for the tops of the frame to open to varying degrees to help control these factors.
Permanence - While a little more effort may be required to monitor your cold frame, its sturdy structure will last much longer than fabric row covers. Row covers, though reusable, usually have to be replaced every two years or so due to wear and tear.
Effectiveness - Row covers will only be effective down to 25 degrees adding about an extra month to your growing season. Cold frames provide more protection from the elements and make it possible to grow all year round.
A custom cold frame built by Edible Eden
Top slides open for access and humidity/temperature control