The first hard freeze of the year is behind us, so you may not be thinking of extending the season because your vegetable garden has already turned from vibrant green to black. For example, I have friends who picked the last of their tomatoes to prepare for and now have wilted and withered plants in the wake of our recent freeze.
But, if your plants made it through the freezing temperatures, perhaps covered with frost blankets like mine, you could enjoy several more weeks to months of gardening with season extension techniques.
There are several ways to extend the growing season, and you do not need a greenhouse. By understanding your landscape, planting cool-season crops and learning techniques to modify the temperatures your plants experience, you can extend the season in your garden.
One of the most important things to understand before you can optimize season extension is the idea of microclimates. Your best information comes from observations of your own home and landscape. Within your landscape, you may notice warm pockets where your plants thrive. For instance, on the east side of your home, you have protection from cool winds with warm morning light. Plants here have a better chance of surviving longer into fall than plants on the southwest or north sides of your home.
Cool-season crops like kale, broccoli, lettuce, spinach, mustards and carrots prefer cooler areas where they receive at least six hours of sunlight. These crops fail quickly on the south side during summer months due to afternoon heat. Now that the beds have recently frozen, south-side gardens may be the perfect place to plant cool-season crops.
Most cool-season vegetables can tolerate a light frost and some snow, but keep a frost cloth or blanket handy for frigid days and hard freezes.
You can also create low tunnels over your garden beds by using PVC pipe anchored to the beds or into the ground with rebar. Once you have the structure, you can use different materials to cover the hoops to protect and insulate your plants.
Depending on the protection needed, garden fabric or frost blankets allow sunlight to penetrate but trap heat, keeping these areas five to ten degrees warmer.
If hard freezes are in the forecast, you can also place a frost blanket directly on top of the plants to trap more of the warm air next to the plant. Then, add additional insulation over the top of the hoops with blankets, burlap, Visqueen plastic sheeting or tarps.
Sun-blocking materials should be removed during the day to allow sunlight to shine through, warming the soil and allowing plants to photosynthesize.
Extending the season for your warm-season crops and planting cool-season vegetables will keep your table full of fresh produce for weeks to months, depending on our weather and your area. If you plant cool-season crops in a cold frame or hoop house, you could be harvesting until it is time to start planting again next year.
Wendy Hanson Mazet is the master gardener program coordinator for University of Nevada Cooperative Extension in Washoe County. For information on gardening, attend our Grow Your Own, Nevada! classes held 6 to 8 p.m., Tuesdays and Thursdays, Sept. 19 to Oct. 12. Have gardening questions? Ask a Master Gardener at firstname.lastname@example.org or visit growyourownnevada.com.
As Master Gardener Program Coordinator, Wendy leads many volunteer horticulture programs including the Northern Nevada Master Gardener Program, Advanced Master Gardener Training Program, Advanced Master Gardener Greenhouse Program and Annual Master Gardener Plant Faire Extravaganza.
She also offers basic and advanced horticulture classes to arborists, green industry professionals and the general public. One of her most well-known programs is the Gardening in Nevada: Bartley Ranch Series, which offers free gardening classes at Bartley Ranch Regional Park in Reno every February and March.
Wendy’s Contact information:
University of Nevada Cooperative Extension
Northern Area/Washoe County Office
4955 Energy Way
Reno, Nevada 89502
Ph: (775) 336-0246, direct line
Ph: (775) 784-4848, main line
Fax: (775) 784-4881