Fight against frost
THERE is something ethereal about walking out into the overwhelming stillness of a frosty morning. The landscape seems suspended; it is like entering a picture.
Although that may seem all very romantic and in reality it is sharp and bracing. Some mornings it can make it very diffi cult to get out from under the covers and the air can literally take your breath away.
Frost is one of those environmental factors which can be devastating to both the garden and the gardener.
Many Tasmanians live in areas that receive frost and will have dealt with losses somewhere along the line and in certain years no matter how well you know your garden we can still get caught out.
Frost happens when solid objects, like the ground, get colder than the freezing point of water and the moisture in the air turns to ice crystals and settle.
When this happens to tender plant tissue, the water inside the cell structure swells and then ruptures as it melts, turning your plant to black mush.
Water holds its temperature extremely well and will actually release heat as it freezes, so watering the night before a big frost is due can help prevent the frost
There are a few ways you can go about protecting your plants from the harmful effects of frost and, like with everything in gardening, you might need to use a combination of techniques to get the best outcome.
The cheapest and most basic form of frost protection is to design your garden in a way that uses hardy plants to shield those that are more vulnerable. A hedge row of frost hardy evergreens like camellia sasanqua can create a micro- climate within your garden where you will have more success growing frost- tender plants.
You can also use the thermal mass of large rocks, brick walls and bodies of water that will heat up during the day and slowly radiate it out at night.
Water holds its temperature extremely well and will actually release heat as it freezes, so watering the night before a big frost is due can help prevent the frost from settling on that area.
You could also use a glass cloche, which is like a big wine bottle with the bottom removed, that fi ts over your plants.
Glass is a good insulator which means cloches are very effective and give the plant good protection but, they can be extremely expensive.
A plastic bottle with the bottom cut off certainly doesn’t have the same insulating or aesthetic qualities but does offer some level of protection.
For larger plants or for groups of plants, simple structures of bamboo poles and hessian are very effective, although something as basic as sheets of newspaper or an old shirt thrown over the plant will work in an emergency.
Potassium thickens the cell walls of plants, allowing them to withstand greater fluctuations in temperature, so a handful of sulphate of potash can help harden up your plant making it more resistant to frosts.
If you do have a plant that has been damaged by frost, resist the urge to clean up the burnt outer leaves, although they can look pretty awful.
It is best to leave them so they can protect the inner, unaffected growth and any new shoots that appear. Wait until the danger is over to cut back the plant if needed.
Frost is usually thought of as a destructive force but it defi nitely has a lot of positive effects in the garden.
Kale is always best harvested after a frost as the leaves are more tender and the fl avour is intensifi ed.
The frosty weather is also one of the reasons why we grow such good berries and fruit in this state as many of these crops need periods of winter chill to produce well next season. Hopefully the thought of next season’s delicious blueberries keeps you a little warmer the next time you are out in the cold.