How to protect tomatoes from fall frost
Q. My tomatoes are finally producing well, just when we are starting to get cold nights. Can you give me some tips for extending the growing season in my vegetable garden?
A. This is a question we often get in the fall, especially from gardeners who grew heirloom varieties of tomatoes that are indeterminate — meaning that they only set fruit when growing conditions are favorable.
There are several simple ways to extend the growing season for your garden:
1. Wrap tomato plants
Wrap your tomatoes plants in old sheets or trap on colder nights. Make sure that the sheet reaches the ground and that it’s removed during the day.
2. Drape plants with 'floating' fabric
Use floating row cover to wrap or drape over your beds on cold nights. It will even protect plants from a freeze. It’s more effective if it’s draped over a frame so that it’s not touching the plant. The row cover doesn’t need to be removed during the day as light is transmitted through the cloth but it should be removed if it gets saturated. You can buy row cover at most nurseries or order it online.
3. Use recycled materials to build cold frame
If you’re really ambitious, build a cold frame over your garden bed. A cold frame is typically a wooden box with a lid, such as a discarded window or sliding glass door. that you can prop open during the day and close at night. However, cold frames can be made from a variety of recycled materials and can also be used as a hot box for growing vegetables all winter long.
A hot box is a cold frame that is heated from the bottom either with composting materials or a heating mat.
Search the internet to find instructions and all sorts of ideas for building a cold frame or hot bed.
4. Go for a greenhouse
To further extend the garden season, build a greenhouse: Either a lean-to against a building or one that is free-standing.
Make sure it has plenty of ventilation during the day.
A bi-metal activated fan is perhaps most efficient to provide ventilation. It will open as the greenhouse warms up and close when it cools down.
5. Hang tomatoes upside down
When nights start getting cold enough for frost to form on plants, you can pull the entire tomato plant and hang it upside down in a cool/dark area with the green fruit still attached. This will allow the green tomatoes to continue to ripen slowly.
To even further extend the gardening season, consider planting a winter garden once your summer vegetables are spent. Most of the cool weather crops like kale, chard, broccoli, cabbage, lettuce, onions and sugar snap peas will make it through the winter here and give you a harvest in early spring. If you plant cool weather vegetables in a cloche, cold frame or greenhouse they’ll simply develop faster than they would in open ground.
To make a simple cloche for you smaller plants, try wrapping visquine — a translucent plastic — around tomato cages and place over plants or use staked gallon milk jugs with the bottoms cut out. These can also be used in the spring to protect newly planted summer vegetables.
The Shasta Master Gardeners Program can be reached by phone at 242-2219 or email firstname.lastname@example.org. The gardener office is staffed by volunteers trained by the University of California to answer gardeners' questions using information based on scientific research.