How to Prepare Your Garden for the First Frost
The first frosty night of autumn can be disastrous for your garden. While some plants do well in cold temperatures, many others die with the simple kiss of frost. Don’t get caught in the cold – here’s how to prepare for the first frost of the season.
Predict when it will happen
Before you can seriously start preparing for freezing, it’s helpful to know when to expect your first overnight freeze. It’s as easy as inserting your zip code into a frost date calculator like this one from the Old Farmer’s Almanac (OFA). Frost calculators extract temperature data from national databases and use it to estimate the average dates of the first and last frost for a given region. (The OFA tool uses data from the National Oceanic and Atmospheric Administration (NOAA) Environmental Information Centers .) Remember that these dates are averages based on historical data, so the actual first frost may or may not match the predictions of the calculator. …
This is where your local weather forecast comes in handy. During the growing season, meteorologists will issue cold weather alerts so farmers can plan accordingly. Here are three commonly used terms and their definitions from the National Weather Service (NWS) glossary (all temperatures are in Fahrenheit):
- Frost Advisory: Extensive frost formation is expected, with surface temperatures usually in the mid 30s.
- Frost warning : Surface temperature is expected to be 32º or below, over a large area and for a long period of time.
- Freeze monitoring: Subzero surface temperatures are possible in the next 24-26 hours.
Neither frost calculators nor forecasts provide enough information when used alone, so it is best to use both. First, get the approximate timeframe using the calculator and then follow the forecast so you don’t miss any alerts.
Classify your plants by hardiness
Cold temperatures affect different plants in different ways. To better protect yours, you need to know which of your plants will survive mild frost and which will not. “Delicate” plants – any plants with delicate leaves, flowers and / or fruits – do not fare well in freezing temperatures than “hardy” plants. Some hardy vegetables, including broccoli, most root vegetables, and Brussels sprouts, do taste better when frozen. (According to OFA’s frost protection blog post , “Roots produce more sugars when the soil temperature is below 40 ° F,” which is pretty good.)
The best way to find out if a plant is hardy, tender, or average is to Google its frost damage threshold or frost damage temperature. This will tell you how cold it must be during the night for the plant to die, and tell you how to properly protect yourself.
Collect delicate plants (or bring them inside)
Your top priority should be delicate plants that won’t survive even the smallest frost. Before the first frosts, be sure to harvest the last spring crops such as tomatoes, squash, corn, and tender herbs such as parsley or cilantro. Houseplants also fall into this category, even if they do not contain the typical “delicate” plants — they lack the volume of soil to retain heat. Be sure to bring your indoor plants to a location with adequate lighting to keep them safe and warm throughout the winter.
Protect everything else
Hardy plants can survive short-term frost, but they still need a little help. Here are some simple methods approved by the old farmer in the Almanac to protect your plants and soil:
- Water thoroughly : Wet soil retains more heat than dry soil, so water abundantly a few days before the first frost.
- Mulch, mulch, mulch: Covering bare soil and short plants with mulch adds another layer of insulation and fertilizes the soil as it decomposes.
- Cover Plants and Garden Beds: Loosely cover any exposed plants with polyester sheeting , sheets or fabrics and secure them with something heavy.
If you think these are all pretty standard winter preparation methods, you are right. When it comes to preparing for freezing, what you do is less important than when you do it. Get your schedule in order and always follow the forecast; everything else will follow from there.