QUESTION: Fabric or plastic is the best material to use as a cover to shield outside plants from the chilly air.
When the temperature drops low enough to cause the moisture on plant leaves and buds to freeze, the threat of frost typically materializes overnight. You must cover plants to prevent the moisture from freezing in order to protect them from cold. It’s crucial to utilize the proper materials, even though an unexpected cold can leave many gardeners racing to find something to cover their sensitive plants.
It is ideal to use a cotton covering because it will let moisture out while yet shielding your plants from cold. Fabric coverings will both capture the heat that is radiating from the ground and stop the freezing air from coming into direct contact with the wetness on the plant. Large plants and shrubs are best covered with bed linens or comforters. Newspaper can be used to low-growing vegetation, but it can frequently be challenging to make it stay put. I have recycled old towels, sheets, and even cardboard boxes as well as pillowcases. Whatever you choose to use to cover your plant, just make sure the canopy traps the warm air within and extends to the ground.
You can use plastic, but it’s crucial to remember that you shouldn’t let it touch your plants. Because it can hold moisture against plant tissues and worsen freezing damage, plastic that comes into contact with your plants is frequently much worse than no protection. For their frost-sensitive plants, many gardeners will frequently install high stakes or forms so they can cover them and secure them without worrying about the coverings blowing away at night or harming the branches. As long as the plastic won’t come in contact with the plant in any manner, it is acceptable to cover a structure like this with plastic.
And keep in mind that the more cover layers there are, the better the insulation is. So, feel free to cover priceless or delicate plants with more than one cover, especially during really cold temperatures. You may, for instance, cover the plant with a sheet of plastic and then an old blanket.
Whatever method you choose, it’s crucial to remove the covering as soon as the risk of frost has gone so that the plant can absorb light and to avoid heat buildup when the sun comes out.
What can I use to protect my outdoor plants?
Planting too early might result in a crisis if a cold snap is impending, whether it was because you were seduced by some striking hue at the garden center or simply wanted to start the gardening season early. It’s not difficult to help your seedlings survive the great frost, but it does take some planning.
When temperatures drop, you can usually rely on improvised protection for plants. The necessary tools must be prepared in advance to protect plants from frigid mornings for larger plantings, such as a food garden.
Knowing when prized vegetation starts to turn frost-burned brown will help you know what to do when freeze warnings are in effect. As a general rule, plants typically freeze when the temperature stays at 28°F for five hours.
There are, of course, exceptions to this rule. When temps drop to 32–33F, seedlings often die because of their delicate new leaves. There are many low-temperature thresholds for tropical plants. Some collapse at temperatures below 40°F, while others break down at 35°F. Other plants are naturally resistant and can endure temperatures as low as 18 to 20 degrees Fahrenheit. Do a search in gardening books and internet resources to discover the threshold for your plants.
Take it up
Moving plants away from potential danger is the simplest cold-protection strategy. Potted plants and seedlings in flats both benefit from this. Moving plants onto a porch with a roof, into a garage or shed, or under a deck frequently provides sufficient shelter.
Rely on Water
Just before sunset, water the soil to raise the temperature of the surrounding air overnight as the water evaporates. Water-filled buckets or gallon jugs should be left in the sun all day. Move them close to threatened plants at night. Air temperatures will be moderated by the water, and if it freezes, heat will be released. To boost midday heating, paint a few water-holding containers black for best results.
the air flowing
The biggest harm is done to plants by cold, motionless air. To prevent frost from accumulating on plants, you can use an electric fan all night to create a breeze. Never forget to keep electrical connections dry.
Plants Should Be CoveredPlants should be covered with sheets, towels, blankets, cardboard, or a tarp to protect them from everything but the harshest freezing (28F for five hours). Inverting baskets, coolers, or any other container with a firm bottom over plants is also an option. Before it gets dark, cover plants to keep warm air in. Coverings shouldn’t ideally contact the foliage. If windy conditions are anticipated, anchor cloth coverings.
When the temperature rises and the frost has melted in the morning, remove coverings. Under dense covers, heat from the sun can accumulate and cause plant death.
Blankets that collapse
Row covers, or gardening blankets, should always be accessible. These covers are created in various thicknesses from plastic or synthetic fibers. Lay row covers directly on the plants, or suspend them over a bed with pegs to form a tunnel.
Activate lights
An incandescent light bulb produces enough heat to raise the temperature of the air around it just enough to keep a plant from freezing. For this method to operate, bulbs must be close to plants (within a distance of 2-3 feet). (Fluorescent bulbs can’t produce enough heat to complete this task.)
Defend specific plants
Set up hot caps
At planting time, stiff plastic containers with venting holes are placed over the individual seedlings. Hot caps function similarly to cloches (small greenhouses), but the daily task of applying and removing the covering is eliminated by venting holes. Use plastic two-liter bottles or gallon jugs with the bottoms cut off and the lids removed to simulate a hot cap (but saved). In the evenings when the weather turns chilly, replace the lids.
A Wall O’Water tepee, which encircles individual plants with a sleeve of water-filled tubes, is a variation on the hot cap concept. During the day, the water absorbs the heat of the sun. The water gently freezes at night, releasing the sun’s stored radiant heat and preventing the air within the tepee from becoming frosty.
What should be placed above plants as protection?
You can cover plants with a variety of materials to protect them from frost.
You can use materials you can find around the house, but make sure they are light, breathable, and insulating. There are various permeable horticultural fleeces and frost protection goods available on the market.
Useful choices include:
- Straw
- Bouncy tape
- towels, bed sheets, and blankets
- Newspaper
- or other organic things like leaves
Will Covering Plants With Plastic Protect From Frost?
Some frost protection can be provided by covering plants with plastic, but the plastic must not touch the plants or the foliage. Use stakes or canes to create a structure over the plant to support the plastic in order to protect your plant from cold. To keep your plants warm, you are essentially building a tiny greenhouse or polytunnel!
At What Temperature Should I Cover My Plants?
If you want your plant cover to rescue your garden, timing is essential! Use your plant cover if it appears that the temperature will drop below freezing. It is recommended to err on the side of caution in this situation because the forecast is not always reliable.
Temperatures of 32 degrees and lower severely harm even the most delicate plants, such as tomatoes. While certain hardier plants, like spinach and chard, may withstand a light frost, temperatures below 28 degrees will cause them to die.
What Can I Cover My Plants With Safely?
Cloth, frost sheets, and light blankets are all effective. It may be a good idea to cover your plants overnight if you are concerned about the possibility of frost damage. The best cover material will increase the surrounding air temperature by several degrees, thus increasing the plants’ chances of survival.
The good news is that you might be able to use things you already have around the house or repurpose something meant for another use to cover your plants.
Can You Use Garbage Bags to Cover Plants?
Yes, provided you securely secure the plant. Garbage bags can be used to cover plants and shield them from frost, but they must not touch the surface of the plants. Create a tent-like structure over the plant using poles and supports to trap warm air. Make sure the trash bag reaches the ground completely.
During the day, remove the bags. Quick removal avoids humidity buildup and enables the plant to absorb heat from the sun.
How are outside potted plants covered?
You might need to give your pots additional protection depending on where you reside. The following are a few choices for overwintering containers:
- Put many pots next to the house or wall on the ground. Put the cold-hardiest plants outside the grouping, and the weaker ones in the middle. Place straw bales around the outside. Putting them together improves the insulation’s mass and volume, shielding them from chilly breezes that could cause freezing and desiccation.
- Mulch pots with straw, mulch, or chopped leaves for further insulation. Snow is a wonderful insulator as well. Grouping pots in a premade pond liner and filling it with mulch is an intriguing concept for insulating containers.
- The only insulation for roots is the wall of the pot itself because the majority of roots usually tend to be on the exterior of the rootball. To insulate roots, place foam along the walls of square pots that is at least an inch thick before planting. Fill the internal walls of rounded pots with foam peanuts.
- Fill the container up with soil and bury the pots there.
- Plant the rootball in the ground after removing it from the container. Clean the container, then keep it inside. Next year, remove the root ball and repot it in the same or a bigger container.
- Burlap, bubble wrap, old blankets, or geotextile blankets can all be used to wrap pots. Since the roots require protection, the entire plant doesn’t need to be covered. The root zone will retain heat thanks to the support of these protective covers.
- Cover plants at night with cloth, burlap, or plastic if low temperatures are anticipated. If you use plastic, make sure to take it off during the day because the heat can hasten the growth of the buds. Additionally, when covering, take care not to harm the plants’ tops. Plant damage from the cold and pests is facilitated by injury.
- To offer further security, place your pot inside of a larger pot. The bigger pot should have extra insulation or sturdy walls for this to work optimally.
Hard freezes may be unusual to nonexistent in USDA Zones 7 through 11, therefore it may not be essential to add insulation or move pots indoors for the winter. There are several tasks, nevertheless, that you should still be mindful of. Plant development will stall in the winter because of the lower temperatures, and watering may become less regular. However, salt can accumulate in the soil and increase toxicity levels. Leach the salts out with water. As required, fertilize plants as well.
Will cardboard boxes guard against frost on plants?
In high school, I worked at a supermarket shop. To my mother’s dismay, one lesson that stuck with me was about brown bags’ thermal characteristics. We transformed brown grocery bags into beer refrigerators. They could hold ice for up to 24 hours when opened up inside of one another and were disposable. The greatest frost protection for your outside plants is either free or inexpensive, in my experience. When the season is through, cardboard boxes and brown shopping bags may be repurposed and make the ideal frost cover.
When a frost is predicted, I just place one of the boxes I keep on the patio over the plant. If you want a quick supply, packing boxes from Home Depot cost about a dollar; alternatively, you can buy empty ones from shops. Many upright plants just require protection for the growing tip. Slip over columnar cacti, Madagascar palms, etc. by opening three to four large brown grocery bags inside of one another. For reuse and storage, fold them.
These straightforward, affordable, and efficient frost shields also respect the environment.
Around my home, both in the ground and in pots, there are many agave plants. I have over 30 different species; it has become a habit! I have a good understanding of agave snout weevils. My issue right now is not that.
I’ve noticed over the past few months that many specific plants appear to be “sick.” With some white powder or flakes scattered throughout, the hue of the core spike turns off-white and yellowish. Eventually, the white powder or flakes and the base both turn yellow.
It appears that mealybugs have attacked your agave plants. Some treatments include removing the sickest plants from the others, spraying the plants with insecticidal soap or water, or cleaning them with a jet of water (follow label instructions). Because of the intense monsoon wetness, we are observing more mealybug evidence this year. The Starr Urbatsch agave collections manager advises, “Keep air circulation around your plants.”
I read you every week, reader remark. Help! The Valley is experiencing a dilemma with our unskilled landscapers and tree trimmers.
Everywhere we look, these men are “penciling” our palms. How can we prevent the catastrophe from growing worse?
My heart broke when I read your article from December 6 in The Republic about a Spanish Colonial home in the F.Q. Story area that included an image of a palm tree. This lovely old house has a tree that has been killed and is now badly damaged.
If you drive to Mesa, you will see a history of the horror of penciling one mile long of palms penciled throughout the years between the 5000 and 4000 block of East University (south side). There are rows of dead, topless “hour glass” trees as reminders of what this method accomplishes.