To know when to cover your plants, you need to know when the plants you have are susceptible to frost damage. Some frost-tender plants need to be covered as soon as the temperature hits 32°F, while others can handle lower temperatures and/or longer freezing periods.
A fabric covering is best because it will allow moisture to escape while still protecting your plants from frost. Fabric coverings will prevent the freezing air from coming into direct contact with the moisture on the plant while also capturing the heat that is radiating from the ground.
Use stakes or another support to keep the covering from directly touching the plants. Covering plants helps protect them from a freeze because it helps retain heat radiating from the soil and keeps them warm overnight.
Once temperatures drop below 40°F, you may want to start covering your plants with a frost blanket depending on what you're growing, which we'll get into in just a bit. Freeze – A freeze is when the air temperature is 32°F or below.
Bed sheets or comforters work best for covering large plants and shrubs. Newspaper can be used on low-growing foliage, but it can often be difficult to get it to stay in place. You can also use old pillowcases, sheets, towels and even cardboard boxes.
For added protection when you protect plants in a freeze, you can place plastic over the sheets or blankets to help keep warmth in. Never cover a plant with just plastic, however, as the plastic will damage the plant. Make sure that a cloth barrier is between the plastic and the plant.
When Should You Cover Plants? Cover your plants at night and remove them during the day when the temperatures rise above 32 degrees F, so that the soil can warm up again. Some outdoor plants won't survive the harsh conditions of winter, bring them inside and use these tips for caring for them through winter.
When should I wrap my plants for winter? This Old House landscape contractor Roger Cook suggests to start wrapping your plants in November. If your plants are new, be sure to cover them for the first two years. The older your plants get, the sturdier they become in surviving winters.
From that experience, I've found the best frost protection for your outdoor plants is either free or cheap. Cardboard boxes and brown grocery sacks make perfect frost cover and at the end of the season can be recycled. I keep various boxes on the patio and when frost is forecast simply put one over the plant.
'Using bed sheets in the garden to prevent plants from frost is a great way to protect your plants from the cold temperatures and keep them healthy,' explains Zeeshan Haider, the CEO of Greenery Enthusiast.
Plants to move inside: Tomatoes, peppers, eggplant and others that will not survive frost. Plants to cover: Potatoes, radishes, spinach, leaf lettuce, beets, mustard. Plants that do not need to be covered: Onions, cabbage, broccoli, cauliflower, carrots, turnips, kale.
Plastic can be used to protect plants from frost, but it's not the best or most effective material. In fact, the horticultural experts here at Green Impressions actually recommend against it. Plastic materials such as vinyl and traditional camping tarps aren't breathable, causing moisture to get trapped inside.
A covered porch usually provides protection from light frost, but the garage or sun room is better for freezing temperatures. A couple days in darkness won't hurt the plant. Or move them out during the day and back in at night, if cold temperatures persist.
Semi-hardy cool-season crops (beets, carrots, Swiss chard, lettuce, cauliflower, potatoes, parsley) grow in minimum daytime temperatures of 40 degrees and higher. They cannot withstand hard frost without some kind of covering or protection.
Some Hardy Perennials Need Winter Protection in the North and Midwest, and Tender Perennials Require Special Protection Methods. Many perennials hardy for your zone make it through winter just fine with no special attention.
Plants may need covering if there's a long period of 25-degree weather, but they probably can survive a very short-lived cold snap during the night, Reeves said. Calm nights are actually harder on plants than nights with light winds.
Frost Advisory - This is when the temperature is expected to fall to 36 degrees to 32 degrees Fahrenheit. Freeze Warning - This is issued when there is at least an 80% chance that the temperature will hit 32 degrees Fahrenheit or lower. Light freeze - 29° to 32° Fahrenheit will kill tender plants.
If it stays cold for more than one night, can I keep my plants covered, or should I remove the coverings at some point? A. Our recommendation would be to remove the cold protection covering once temperatures are above 32 degrees.
Hardy plants can be hardened off when the outside temperature is consistently above 40° F. Half-Hardy plants may be hardened off at 45° F.
Usually, covering plants with any plastic material isn't safe. However, you can cover your plants with garbage bags to protect them from pests and pest-carried diseases and sometimes excess moisture from too much rainfall.
Covering Plants with Plastic Bags
If the bush is small enough to cover, you can fit a clean plastic garbage bag over or around it and possibly save the buds. For larger shrubs, you can even cover with a sheet or a plastic tarp. You may also use a dark colored bag if that's all you have.
Plastic bags are an essential tool for today's indoor gardeners. They are not only terrific plant sitters when you skip off for a winter weekend, they also help when your plant is not doing well. You can keep houseplants without water for several weeks in a polyethylene plastic bag.
Cover Plants – Protect plants from all but the hardest freeze (28°F for five hours) by covering them with sheets, towels, blankets, cardboard or a tarp. You can also invert baskets, coolers or any container with a solid bottom over plants. Cover plants before dark to trap warmer air.
In fact, you can leave plants covered with blankets or sheets for several days without harming them if freezes are likely for several nights in a row. But eventually the covers must be removed so the plants can get light.