Shading plants against frost and cold weather is vital to plants getting through and is even more important with plants which are not naturally hardy in colder conditions or when unexpected/sudden early/late frosts occur. The trick is to make them not go below the freezing point and cold winds.
This is all you need to know in order to preserve your exterior plants:
1. Know your plants and know your climate
To know which of your plants should come indoors before a cold snap arrives, find out which ones are “tender” (those that are easily damaged in a frost) and which ones are “hardy” (those that can be left out in freezing temperatures). Know, also, your normal frost dates in spring and fall.
- Tender Plants: Annuals such as petunias, or impatiens, most vegetables (tomatoes, peppers, basil), tropical plants (hibiscus, cannas) and recently planted perennials or shrubs. These must be singled out to have the utmost protection.
- Moderately Hardy Plants: There are tendencies of some evergreens, perennials and shrubs that can withstand light frost as long as it is guarded against strong freeze conditions or a lengthy cold.
- Hardy Plants: A number of mature perennial, tree and shrub plants that are native to cold weather. They have the habits of going into dormancy and they can survive freezing temperatures without assistance.
2. Water Intelligently Pre-Freeze
This does seem counterintuitive, but it can be beneficial to water your plants deeply in the afternoon before a forecasted frost.
- Heat is retained in the soil more in a wet condition than in a dry state. It is a kind of insulator which will radiate warmth upwards at night.
- There is a release of latent heat of water freezing. The water in the soil will put out a little heat as it freezes and this can help maintain the air near the plant a bit warmer.
- Plant cells that are well hydrated are sturdier. The water-filled cells are plump, and this reduces the risk of being harmed by ice crystals which start to form inside the cells.
- Critical Point: Watering should be avoided when the ground is already extremely hard especially since it will do you no good but may cause problems. And, too, do not get water on the leaves just before a freeze (if possible) since that water can freeze on the leaves and injure the plant.
3. Take Potted Plants Indoors
Plants in containers work best and easiest by this means.
- Take them into a conservatory: Young plants in pots can be brought into a garage, shed, covered porch or unheated conservatory or even into the house.
- Group containers: One way to create a microclimate in this weather is to group container-grown plants together in a sheltered place (such as the warm side of a house), where they will form some of their own protection. The plants will provide some form of protection against wind and cold to some of the other plants.
- Wrap pots: With houseplants that will be kept out of doors, cover the sides of the pots with bubble wrap, thick burlap bags, old blankets, or even newspaper linings. This protects the roots that are more likely to freeze in pots compared to the earth. The insulation effect can also be achieved by burying the pots into the ground or what they call as plunging.
4. Plants of cover on ground
The next alternative defence in case the plants cannot be transferred is to cover them.
- Selecting the correct material:
- Frost cloth/Horticultural fleece: This made-to-protect cloth is breathable and made specially to cover plants. It will permit light, and air to enter and escape with a little moisture, and retains the heat. You are allowed to leave it on few days when necessary.
- Old sheets, blankets, burlap or even cardboard boxes: These will also be effective either to temporarily protect a plant, such as overnight frost.
- Anthony Hamilton The problem with plastic is that even though it traps the heat it also conducts cold rapidly. It may be much worse when plastic comes in contact with the leaves. When you have to use plastic, you should not allow it to come into contact with the plant.
- And how to cover:
- Loosely drape the cover over plants: It is important that the cover covers the plants right to the ground so that the heat generated in the earth is trapped inside the cover.
- Support with stakes: Use a series of stakes, tomato cages or some other support to make what looks like a mini tent above the plant when plants get large. This prevents covering things too hard and can make an air pocket, which aids in insulation.
- Secure the cover: Place rocks on the cover or bricks or garden tsaples that will keep the cover held down as not to get blown away by the wind.
- Lift covers during daytime: Take off a cover during the daytime, when the temperature warm up again, unless breathable frost cloth is used. This gives sunlight, air and avoids overheating. Apply again in the evening in case of continuing danger of frost.
5. Root Protective Mulch
A large amount of mulch is an absolute must to cover the soil base and to keep roots safe of plants, particularly, tender perennials, freshly planted trees, and shrubs.
- Lay it on thick: Cover the soil around your plants with 2-4 inches (5-10 cm) of organic mulch such as straw, wood chips, shredded leaves or pine needles.
- Insulation: It is a cover that can be said to be a blanket which helps to maintain a constant temperature in the soil thus the ground does not freeze too much.
- Frost Heave: Mulch can also prevent what is known as Frost Heave or the movement of the plant out of the ground as a result of soil experiencing freezing and thawing.
- Winter Protection: If it is low spreading plants or dormant perennials, even the whole plant can be covered with a layer of straw over full, then removed in the spring.
6. Microclimates and Windbreaks
When organizing the composition of the garden, consider the microclimates and windbreaks in the garden.
- Consider certain spots in your garden.
- Sheltering Places: And do not plant tender stuff where there is no protection such as up against a south-facing wall of your house which will help block the wind and take up the sun and reradiate it.
- Aid Frost Pockets: Cold air is denser, and it sinks. Areas that are low in your garden may form frost pockets. It is not wise to plant very tender plants there. Do you have a good fence or hedge that keeps the draining of the cold air out, then think of creating an opening or reduction in the hedge to allow free flow of the cold air.
- Windbreaks: Cold winds are extremely drying to the plants and this causes severe drying off of plants at best and killing eversgreens as well. Provide a windbreak around susceptible plants by using fences and walls or even temporary burlap screens.
7. No Crop Late Season Fertilising
You should not use nitrogen-rich fertilizers in late summer or early autumn.
- Growth is tender: Nitrogen promotes rich, soft new growth, that is extremely susceptible to frost.
- Let them Harden off: The cold itself does the above-advised slowing of the growth, and is useful in providing hardy vegetables or hardening off. This process is destroyed by late fertilizing.
8. Observe Forecasts and Take an Action
Be up to date on the local weather forecast. It is this random cold snap that is more harmful than the foreseeable, longer winter. Make sure that you are fast enough in taking action when frost warnings are declared.
When you add these proactive techniques, along with taking action in time, you have a great chance of saving your outdoor plants and even making them live whilst the cold weather and the frost persist.
