Protecting plants from spring freezes

How To Protect Your Garden

  • Water the soil thoroughly – wet soils hold heat better than dry soils.
  • Move containers or unplanted plants indoors or in an attached garage that will not reach as low of nighttime temperatures.
  • Insulate sensitive outdoor plants with leaves, mulch, straw, etc. to protect plants leaves/crown.
  • Use blankets, tarps, drop cloths, or plastic sheets to trap ground heat around plants. Keep coverings from touching foliage whenever possible.
  • Anchor coverings to the ground to protect them from blowing in the wind, allowing heat to escape.
  • Uncover plants & return plants outdoors when temperatures rise the following day.
  • Plan to provide more care this spring and summer to damaged plants in order to help them recover.

What To Expect:

  • Plant damage will vary based on many factors, including the type of plant, how low the temperature drops, the duration of that low temperature, moisture, and how gradually or quickly the drop in temperature occurs.
  • In general, flowers are more easily damaged than leaves, especially for flowering trees.
  • At 30-32 Degrees F, the impacts of freeze damage should be minimal to most plants.
  • Most cold damage occurs at temperatures of 28 Degrees F and below.

How Cold Affects Different Plants:

  • Cool season plants (pansies, daffodils, crocus) or cool season vegetables crops (leafy greens, root vegetables) should be fine with this weather.
  • Cold sensitive plants, such as summer annuals (geraniums, marigolds, etc.) and summer vegetable crops (tomatoes, peppers, etc.), will need significant protection.
  • Perennial plants (hosta, lilies, bleeding hearts, etc.) may experience damaged foliage, but their roots & crowns should be mostly unharmed.
  • Most perennials and trees & shrubs should be able to send up a second flush of growth in a few weeks if leaves are damaged by cold.
  • Fruit Trees vary by stage of development & temperature: www.canr.msu.edu/uploads/396/36740/PictureTableofFruitFreezeDamageThresholds.pdf

After The Cold Has Passed:

  • Uncover plants & return plants outdoors when temperatures rise the following day.
  • If foliage is green, leave it.
  • Brown, tan, mushy, or water-soaked leaves can be removed.
  • When in doubt, wait to see if regrowth occurs, and prune damaged plants back to where regrowth occurs.
  • Provided supplemental water when needed in order to prevent additional moisture stress on the plants.
  • Do not fertilize until new growth starts so plants can maximize fertilizer use. Be sure not to over fertilize.