Cold Protection for the Winter Garden

While most of Florida does not have to worry about freezing winter weather, the Florida Panhandle is certainly an exception. North Florida experiences a few hard freezes – temperatures less than 28°F for over five hours – every year. Although most of our cold weather occurs in January and February, we can expect our first frost around the second week of November. Therefore, it is important for gardeners to be prepared.

Most of the Panhandle is in zone 8b, which means average minimum temperatures are between 15 and 20°F. Nights – especially consecutive nights – that get this cold can “burn” the tips of even the toughest vegetables, such as collards and kale. It is also important to remember that if you live in a more rural area, temperatures will be slightly cooler, relative to the city. Frost is also more likely to occur on clear nights, as heat that radiated down from the sun during the day will escape the atmosphere at night, if clouds are not present. Also, if you were late getting your fall garden started, it is even more important to protect your vegetable plants, as young plants are more susceptible to cold weather.

One strategy home gardeners can use to protect their plants during cold weather is to use frost cloth. Frost cloth is a breathable polyester fabric that is light weight and heat-retentive. It can moderate temperatures about six to eight degrees Fahrenheit. Use it on all of your garden plants if there is a hard freeze, but do not cover cold hardy vegetables in mild frosts, as their flavor can actually become sweeter in cool weather, and the plants will become more tolerant to the cold.

Frost cloth can be found at most plant nurseries, and it can last multiple years if you take care of it. Use wire hoops to keep the cloth off smaller crops, as ideally the cloth should not touch the plant. Most importantly, the cloth must touch the ground at all points to be effective, as it works by trapping heat that radiates from the soil and increases the humidity around the plant.

In the morning, do not remove frost cloth too early, as quick thawing can actually cause the most severe damage. Wait until the outside air temperature is about 50 to 60°F. Since frost cloth is breathable, if temperatures do not reach 50 to 60°F during the day, you can leave it on multiple days.

Sheets or blankets (not plastic) can be a frost cloth substitute, but there are disadvantages, such as not allowing proper air circulation or not being large enough to reach the ground.
Another strategy that can help keep your garden safe from cold weather is to keep your plants well watered, as frost damage is actually dehydration. When ice crystals form on the leaf surface, it draws moisture from the leaf tissue. Damage will therefore be less severe if the plant is not already drought-stressed. You can also mulch around the base of your plants with wood chips or straw to help moderate soil temperature and retain moisture.

Being prepared for cold weather will help keep your vegetable garden going strong all the way into the spring. Remember that healthy plants will be more resistant to cold weather than unhealthy plants, and investing in a few sheets of frost cloth can go a long way to ensure your veggies survive our chilly North Florida winters.