Did the weather forecast predict the first cold snap of the season? This is the time to offer your plants an extra layer of protection from the cold weather. Frost protection is important not only for annual flowers and tomato plants (if you're lucky enough to still have some holding on), but even young evergreen plants, tender perennials, and hardy vegetable crops can be affected by a light freeze.
"Frost can be a challenge for both late-season and early-season garden beds, but with the right strategies, you can protect your plants and help them survive the non-ideal weather," shared Amy Enfield, Ph.D., Senior Horticulturist at ScottsMiracle-Gro. "Beyond using covers and mulch, factors like soil fertilization and watering play a role in helping vulnerable plants withstand cold temperatures." Enfield brings over 25 years of experience in the lawn and garden industry. To learn more about how to protect your plants from cold damage and winter frost, we tapped her for more expert advice.
Tend to the Baby Plants First
"Native and hardy perennial plants have adapted to withstand freezing conditions better than tender annuals, but even newly planted hardy plants can be sensitive to the cold until they have established a strong root system," notes Enfield. Pay attention to the tender plants in your landscape that are more susceptible to extreme damage. If you'd worry about them in a wind or hail storm, pay them extra attention before the frost, too.
Water Plants Before the Frost
At the first threat of frost, take it as a sign to water everything. "Well-hydrated, healthy plants are better equipped to handle frost," she notes. "Watering your garden plants in the morning prior to a frost helps the soil absorb as much heat as possible during the day. This is because moist soil retains heat better than dry soil; however, avoid overwatering, as waterlogged wet soil will cause unwanted plant stress."
Feed Your Plants
"Routine care throughout the year protects your plants from frost damage," shares Enfield. "Healthy plants are better able to survive harsh weather. Regular feedings with a plant food product like Miracle-Gro Shake ‘n Feed All Purpose Plant Food help plants build strong root systems and support their overall health–including tolerance to frost and other adverse conditions."
She adds, "Avoid fertilizing with organic matter late in the growing season, particularly with high-nitrogen fertilizers since this can encourage tender new growth that is very vulnerable to even light frost damage."
Use Mulch as Insulation
"A 3- to 6-inch layer of organic mulch, such as Miracle-Gro Organic™ All Natural Mulch, straw, wood chips, or shredded leaves, helps insulate the soil, trapping heat and protecting roots from sudden temperature drops," reminds Enfield. Be sure to keep the mulch several inches away from plant stems to avoid damaging the plant.
Use Covers or a Cold Frame
"For frost-sensitive plants, at dusk cover them with frost cloths, burlap, or even lightweight blankets and sheets whenever a frost or freeze is expected," suggests Enfield. "These materials trap warmth from the soil and prevent frost from settling directly on foliage."
This is a time when method matters. "Covers should be propped up so they aren’t laying on the plants — this promotes both air circulation and prevents the plants from being crushed," she notes. "Individual plants can be covered with cloches or by covering them with bowls or buckets." Don't forget to remove the covers during the day once air temperatures rise to let the plant soak in some sunlight.
Relocate Container Plants
"Container gardens can be temporarily relocated to a garage, shed, or basement to protect them from frost," reminds Enfield. "You want a spot that protects the potted plants from freezing temperatures but not so warm that it shocks them or stresses them out. If you can’t move your containers indoors, pack them close together and cover them with a sheet to help trap the heat."
Can frost blankets really protect plants from ice crystals?
Sure can. Horticultural fleece and plastic sheets act as physical barriers that shield plants from frost damage. While garden fleece is breathable and will trap heat without overheating plant cells, plastic sheets are better suited for short-term use. Also, remember to secure the plastic sheet with a heavy object, or it'll just blow away like a kite in the wind. Both options help keep your favorite plants alive during unexpected frost warnings.
How do I learn the average frost dates in my area?
Average frost dates vary based on your region, and checking these dates helps you plan protective measures. Check local agricultural resources for specific frost warnings and timing, and more importantly, monitor the weather day-to-day, especially the overnight temperatures. Many areas will put out a frost advisory to help residents plan protection for plants and other outdoor fixtures.
