How To Use A Freeze Protection Themostat To Protect Plants

Keeping semi tropical plants like lime trees and orange trees alive during winter can be a challenge even in temperate climates such as the south.

One way to keep outside citrus trees or other non cold hardy plants from freezing is to place them in a temporary enclosure or makeshift greenhouse. This may be enough to raise the temperature around the tree and keep it from freezing but you may also want to place a weatherproof light bulb inside the enclosure.

How to make a shelter for a lime or orange tree.

You will need 12 two by four, pressure treated boards. Measure four of the boards and cut them at the halfway point. Use four of these equal length boards to make a bottom square frame and the other to make a top square frame.

Then depending on the height of your lime or orange tree cut the four long two by four boards you have left to just above the height of the citrus tree.

Using two and a half inch deck screws, attach the four legs to the bottom square frame you made and when you are done attach the top square frame which will be the roof.

Your square frame should look like a rectangular box. You can now attach some 6 mil clear plastic with a staple gun. Leave a side open for a door. You can close this by stapling it shut or make a more permanent door using a one by two and a couple of hooks to close it with.

Now you will need to place some kind of heat lamp inside. For most climates a one hundred watt light bulb is enough. Use a weather proof shop light and hang it from a wire or bungee cord stretched across the top of the enclosure.

You can use an automatic freeze protection thermostat or switch such as the Easyheat 38. This device will turn the light bulb on when temperatures dip below 38 degrees and turn it off automatically when temperatures get over 50 degrees Fahrenheit. Another model that works well for turning on lights to keep plants warm is the TC-3 Thermocube, which turns things on at 35 degrees or colder and off when it warms up to over 45 degrees.

Freeze protection thermostats are made primarily for use with pipe heating cables but will work fine with a light bulb and will help keep your plants from freezing by automatically coming on when freezing weather comes.

Just make sure the bulb does not touch the outside plastic and this will keep your citrus tree or other plants from freezing.

Freeze protection thermostats are generally not waterproof. Keep them in a covered area but exposed to outside air so that they will still activate when it is cold.