Materials to Protect Plants from Frost

December, 2006 - I was once a Boy Scout, so you would think that "Be Prepared" would be the foundation for my approach to gardening. Not quite. I have, instead, developed the lazy man's approach to being prepared - set up the garden so you don't have to run around like crazy when disaster strikes. The approach works - most of the time. For example, the majority of my plantings in the old house were under a heavy oak canopy, which acts as an insulator in cold weather. For those plants that were more susceptible to frost, I kept them close to the house or the pool, which are good sources of retained heat. So when a frost threatened, I did nothing - I was already prepared.

Then there would be the occasional frosts that defied my meager preparations. I would hear the weatherman announce in the morning that a severe killing frost was expected for the Tampa Bay area that night and that residents should make preparations to protect their plants. Reacting in fear, I would first consider how I could move the more fragile plants inside. That was a waste of time, since there was no way I could move four 8' tall ficus trees into the house. Ok, go to Plan B. All the gardening sources recommend wrapping fragile plants in old blankets, sheets or towels. That just means finding enough fabric to cover 300 to 400 square feet of impatiens, ficus, herbs and other sensitive plants. But try telling your spouse that you want to empty the linen closet to save a few plants with the likely result that all the linen, at least the linen that survives being laid on the ground or wrapped around trees, will need to be washed, dried and folded. Ok, Plan C. Rush down to Home Depot and buy a roll of burlap to protect the plants. The only problem is that when you arrive at Home Depot you find that the Boy Scouts have come and gone - and in the process bought up every roll of burlap or frost protection fabric in the store. Finally, Plan D. Go over to the landscape supply section and look for Weedblock Landscape Fabric. It costs the same as burlap (per square foot) and works far better. It's light in weight, the black surface attracts and holds heat, and the fabric has small holes that allow for some air movement if you have to leave the fabric on the plants for several days.

By the way, avoid Plan E - plastic. While plastic is cheap and light, it does not allow for air circulation and is a poor insulator. If you do use plastic, try using wood or PVC pipe to suspend the plastic and keep it away from direct contact with the plant.

January, 2008 - A couple of things to keep in mind:

  1. If you do opt for Weedblock Landscape Fabric, make sure you buy it in 6' (not the 3' and 4' widths).
  2. Cold Protection Bags (such as Plankets or Frost Protek) are becoming popular and are carried by stores such as Home Depot. They are pricey, but if you have a prized plant, the bags may be a good option.
  3. If you are looking for additional sheets and your closet is bare, you might try the local thrift store as a source.
  4. Some people suggest using the outdoor Christmas lights as a source of warmth under the protective blankets.
  5. For an idea of the steps I took during the hard freeze in January, 2008, click here.