Some years the first fall frost comes a little early, and other years we don’t see a cold front until late in the fall. Anytime though that temperatures dip near or below 32, there’s potential for damage in the garden.
Frost in the Garden
Cold, windy weather can be a death sentence for tender perennials and many annuals.
Additionally, sudden temperature changes like we often see in North Texas – warmer weather followed by several below average, cold nights – don’t allow plants time to acclimate slowly, making frost damage and death more likely.
We gardeners can be an intrepid group of hardy souls not wanting to let a little cold ruin our fun. We can choose to let the first winter freeze kill our tender perennials, seasonal color or summer vegetables, or we can fight the clock, try to beat back the frost and hope to garden for a few more weeks. But we would be wise to choose our battles!
Saving Plants or Letting Go
Bring your frost sensitive potted plants indoors – tender perennials like tropical hibiscus and tender herbs like lemongrass. Make sure to first water thoroughly to leach out any salts (and run off any ants that have taken residence in the soil!), and check for bugs before relocating indoors.
Our summer annuals are finished for the season; you can pull these and add them to your compost bin. Cool season annuals like pansies, violas, and flowering kale will survive through the winter and won’t die back until the weather gets too warm. If however you have only recently planted your cool-season annuals, you may want to cover them with frost cloth during the colder nights predicted to be 28 degrees or lower.
Many summer veggies can be protected from a light frost but can not survive a hard frost or especially several freezing nights, so get out there and harvest any last of your summer crop before the cold weather claims them! Any remaining green tomatoes on the vine can be picked and left on a window sill to ripen.
Harvest and preserve warm-season herbs. Many herbs can be frozen with minimal loss of flavor. Make a large batch of basil pesto to freeze for a taste of summer throughout the winter (or for a thoughtful hostess gift during the holidays).
Cool-season veggies should be fine, but young seedlings may need protection from frost until established. For more on vegetables and the various factors that affect plant survival, check out this informative article from Botanical Interests: Frost Tolerance of Vegetables.
Some perennials die back to the ground with the first hard freeze and lay dormant until spring. Last fall I covered my tender perennials like Texas Lantana, and a stretch of warm weather following the frost allowed me to enjoy their beautiful colors over Thanksgiving. But this year, with several frosty nights lined up and no warm spell on the horizon, this effort may be futile. Sometimes it is best to let nature take its course! Your tender perennials will be back with renewed vigor come spring to bloom once again.
Native plants have adapted to local weather conditions for thousands of years. They are acclimated to North Texas weather extremes and wild fluctuations like we will see this week, so generally, you don’t need to worry about any of your natives.
For all other plants in question, check hardiness ratings to find out the lowest temperatures they can withstand, and protect accordingly. This information is available on plant labels, so be sure to keep a detailed record of what you plant. With a little googling, you can also find the hardiness zone for any plants you are unsure about.
Hardiness ratings are just part of the equation for determining plant survival. Several other factors can be in play. For instance, keep in mind that young plants just recently in the ground have a harder time surviving temperature extremes than more mature, well-established plants.
Preparing Your Garden for a Freeze
Now that you have an idea of what will survive, what is worth saving, and what to let go (and harvest!), here are a few basic tips:
- Plants suffer less damage if the ground is moist, so give the ground around your plants a thorough watering (use a moisture meter to determine if the soil is dry).
- Cover tender plants and seedlings with frost cloth or old sheets when temperatures drop.
- Do not use plastic; it can burn plants if left on in full sun.
- Mulch bare ground and pots to hold moisture in and insulate roots from temperature fluctuations.
Keep in mind that you may see brown spots on leaves and flowers where the cold has burnt the plant tissues. Your plant should be fine, but you may remove unsightly brown foliage if they bother you. Just DO NOT do any heavy pruning that may encourage new growth during winter when plant energy should be directed to the roots.
For more on protecting your plants throughout the winter, see this post on winter garden tasks. Keep warm, and good luck! Are you making any special efforts to save anything in your garden?
Editor’s Note: This post was originally published in 2014.