Keeping plants warm during cold weather can be challenging, but is crucial for protecting sensitive plants and extending the growing season With the right techniques and strategies, you can create a warm microclimate that will allow your plants to thrive even when temperatures drop In this comprehensive guide, we’ll explore the best methods for protecting outdoor plants and indoor plants from the cold.
Why Do Plants Need Protection from the Cold?
Most plants are adapted to the seasonal temperatures of their native climate. However, extremes of cold can damage or even kill plants by:
- Freezing the water within plant tissues, causing cells to rupture
- Slowing or stopping photosynthesis
- Allowing frost to penetrate roots and damage vascular tissues
Tender tropicals, summer annuals, and young seedlings are especially vulnerable. Even hardy plants can suffer when temperatures plummet well below their comfort zone. Providing warmth helps reduce cold injury and keeps plants actively growing longer into the fall and earlier in spring.
Protecting Outdoor Container Plants
Outdoor plants in containers are more exposed than in-ground plantings. Their roots are completely surrounded by cold air instead of insulating soil. Here are some ways to keep container plants warm:
Move Containers Together
Group pots and planters close together to protect them from wind chill. The mass of plants will create a warmer more stable microclimate.
Insulate Pots
Wrap insulation around the sides of pots to keep roots warmer. Slip pots into insulated plant sleeves, or wrap them with bubble wrap, burlap, straw, foam pipe insulation, etc.
Add Heat Sources
Place heat-generating items like outdoor patio heaters, incandescent lights or electric heating mats near plants. Use heating cables designed for plant containers.
Use Protective Covers
Shield plants with cloches, cold frames, fabric row covers, and other protective structures. Water-filled plastic gallon jugs can hold heat overnight.
Choose Protected Locations
Site containers next to heat-retaining walls or in a greenhouse to block wind. Move small pots to a sunny windowsill or unheated garage or porch.
Protecting In-ground Plantings
Although better insulated, in-ground plantings can still benefit from extra protection:
Apply Organic Mulch
A thick layer of bark chips, leaves, straw, or other mulch insulates the soil and plant roots from cold.
Wrap Shrubs and Trees
Burlap or breathable fabric wraps protect branches and trunks while allowing sunlight to reach leaves.
Make Temporary Cold Frames
Surround beds with cloches, hoop tunnels, and cold frames covered in plastic sheeting or greenhouse film. Ventilate on sunny days.
Add Row Covers
Lightweight floating row covers trap heat but allow air, light, and moisture to penetrate. Avoid direct contact with foliage.
Install Permanent Structures
Greenhouses, cold frames, tunnel houses, and other permanent structures offer options for keeping large plantings warmer in winter.
Creating Warm Conditions for Indoor Plants
Indoor plants need protection from cold drafts and low humidity in winter. Here are some tips:
Monitor Temperatures
Use a thermometer to identify the warmest and coldest spots. Maintain minimum temperatures as required by each plant.
Humidify the Air
Keep humidity above 50% to prevent dessication. Use humidifiers or set plants on trays filled with pebbles and water.
Insulate Near Windows
Close curtains and blinds at night. Move plants away from cold window glass. Apply insulating window film or acrylic panels.
Avoid Drafts
Block air leaks under doors and windows. Close vents and chimneys when not in use. Don’t place plants in drafty areas.
Grow Under Lights
Supplemental lighting adds warmth while allowing growth to continue when sunlight is limited.
Emergency Measures for Cold Snaps
When faced with an unexpected freeze, cold front, or snowstorm, emergency action may be needed to prevent plant damage.
Cover Plants Outdoors
Drape plants with bed sheets, drop cloths, garden fabric, or nursery coverings. Remove coverings during the day to avoid overheating.
Move Potted Plants
Relocate containers to warmer microclimates like greenhouses or indoor spaces. Even a garage or enclosed porch is better than leaving them exposed.
Insulate Above-ground Stems
Wrap papery tree bark and exposed herbaceous stems with insulation. Avoid damaging branches with heavy coverings.
Wrap Pipes and Faucets
Outdoor plumbing may freeze, preventing watering. Insulate and wrap pipes and spigots, or drain irrigation systems for winter.
Check for Damage
Once temperatures warm again, assess plants for injury. Prune dead sections but avoid major pruning of stressed plants. Water thoroughly if soils are dry.
Choosing Cold-tolerant Plants
The easiest way to avoid winter damage is selecting plants with good cold hardiness for your climate zone. Some options include:
- Ornamental kale and cabbage
- Hardy sedums like Autumn Joy
- Evergreen trees like pine, fir, spruce
- Shrubs like lilac, rose, and potentilla
- Perennials like iris, peony, ornamental grasses
- Cool-weather vegetables like kale, carrots, and onions
Check plant tags for the lowest recommended temperature range and other indicators of winter hardiness.
Protecting your plants from cold doesn’t need to be difficult or expensive. With a combination of insulation, protection from wind, maintenance of ideal temperatures and humidity, and proper plant selection, you can help your plants not just survive, but thrive through the colder months. Pay close attention to forecasts so you can proactively prevent damage before it occurs.
#7 Adjust Your Watering Routine
Of course your plants need water, but they probably won’t need as much as you think they do. During the winter months, some plants enter a dormancy period to essentially wait out the cold weather. Because of this, they don’t require as much water as they normally do. In fact, you should only give your plants approximately a third of their normal water ration. Reducing the amount of water will keep your soil drier and warmer. When you do water them, be sure to use warm tap water instead of cold.
#2 Use a Space Heater
An ideal temperature for most plants is between 60 and 75 degrees. A space heater is a convenient way to keep both you and your plants warm. Adding a space heater to a room is a simple way to maintain a consistent temperature during the day (never run a space heater overnight or leave an unattended space heater running). When using a space heater, be sure to keep your plants out of the direct path of the heater to avoid heat damage.
3 Thrifty Ways To Keep Plants Cozy This Winter!
FAQ
What can I use to keep my plants warm?
The best way to mitigate frost is to bring them in a greenhouse or indoors. Alternatively, cover your plants with bubble wraps, plastic tarps, mulches, old blankets, and burlap nets.
What temperature is too cold for plants?
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General Guidelines:
- 50°F (10°C) or below: Many plants, especially those not native to cold climates, can experience cold shock or damage at temperatures below 50°F.
- 32°F (0°C) or below: Temperatures at or below freezing can cause ice crystals to form within plant cells, leading to irreversible damage and potentially death.
- 50°F (10°C) or below: Many plants, especially those not native to cold climates, can experience cold shock or damage at temperatures below 50°F.
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Plant-Specific Considerations:
- Tropical Plants: These are highly sensitive to cold and should be brought indoors or protected from temperatures below 50°F.
- Subtropical Plants: These are more cold-tolerant than tropical plants but can still be damaged by temperatures below 40°F.
- Hardy Plants: Some plants, like certain cool-season annuals (pansies, violas, etc.), can tolerate temperatures as low as 30°F (or even lower).
- Tropical Plants: These are highly sensitive to cold and should be brought indoors or protected from temperatures below 50°F.
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Factors Affecting Cold Tolerance:
- Plant Type: As mentioned, some plants are naturally more cold-tolerant than others.
- Root Exposure: Plants in containers are more vulnerable to cold damage than those planted in the ground because their roots are more exposed to the cold.
- Duration of Cold Exposure: Short periods of cold may not be as damaging as prolonged exposure.
- Wind: Wind can exacerbate the effects of cold temperatures, so it’s important to protect plants from the wind, especially if they are in containers.
- Plant Type: As mentioned, some plants are naturally more cold-tolerant than others.
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Protecting Plants from Cold:
- Bring Plants Indoors: If possible, bring sensitive plants indoors when temperatures are expected to drop below 50°F.
- Cover Plants: Use blankets, burlap, or frost cloth to protect plants from frost.
- Mulch: Add a thick layer of mulch around the base of plants to insulate the roots.
- Water Plants: Water plants the evening before a frost is expected to help them retain moisture and protect them from cold damage.
- Research Your Plants: Before planting, research the cold hardiness of your plants to ensure they are suitable for your climate.
- Bring Plants Indoors: If possible, bring sensitive plants indoors when temperatures are expected to drop below 50°F.
How do I keep my plants from getting too hot?
A layer of mulch over the roots of your plants helps in two ways: It insulates the soil against extremes of temperature, and it prevents moisture from …Aug 23, 2023
How to make a room warmer for plants?
Add a layer of plastic/glass, with an inch air separation from the existing layer. Add thermal mass inside. Build or buy a retractable insulated cover for nighttime. If you are in a northern latitude, insulate the north side.
How do you keep plants warm in winter?
It keeps the roots cool and moist in summer; warm in winter. Cover your beds with a layer of mulch to protect your plants from harsh winter conditions. Spreading mulch in your garden helps protect the soil from damage caused by wind, cold, frost or heavy rains. Organic mulch options include:
How to warm indoor plants in winter?
There are a few ways that you can warm indoor plants during the chilly winters. One way is to add a space heater to your room. Just be careful not to place the plants too close to the space heater as this can burn them. Houseplants in general do not like drafts of any sort, especially very cold or very hot drafts.
Why is it important to keep plants warm outside?
As fall shoulders in, it is important to keep plants warm outside, especially those that are not frost hardy or cold tolerant. Our fruit and vegetable crops are classic examples of those that will need extra steps to keep them alive and producing.