Sunday, June 23, 2024

The freedom of the press still furnishes that check upon government which no constitution has ever been able to provide – Chicago Tribune.

HomeIssue 20Gardening: Geoff Miers vs Jack Frost

Gardening: Geoff Miers vs Jack Frost


On average June has 10 frosts, July has 12 and August eight with one frost in September. These are averages and in some years the number of frosts can be 50% more than the average, equally it can be less.

To date we have had approximately six to eight frosts with three frosts forecast over the three days.

Over the past four decades a series of wet years have been followed by exceptionally cold winters. This hasn’t eventuated to date after a relative wet summer, but there is still plenty of time.

When the drought broke in 1974 we had several wet years with some great cold winters in the late 1970s and following the wet years of 1999 to 2001 the following winter in 2002 saw black frosts with ground temperatures of minus 10 to 12 degrees that wiped out mature trees up to five or six metres tall and large old shrubs, cutting them down to ground level.

So what can the home gardener do to protect their gardens and lessen frost damage?

Aside from totally insulating individual plants or providing central heating for shade / glass houses and patio gardens little will protect plants from black frosts, we simply need to pray that we don’t experience any this winter.

Shade houses and nurseries can be wrapped in plastic to protect prized plants. The plastic will keep out cold winds, ensure warm day time temperatures and to an extent limit frost damage, however, more is required for the coldest nights as frost can move through plastic.

Back in the 1980s I used to light a series of kero lanterns nightly and these would create a warm blanket of air at ceiling height, keeping off the frosts. Murray Neck used the same method by placing a kero lantern at the base of his exotic fruit trees to provide frost protection. While a little time consuming it is a relatively cheap method of heating.

For the really prized plants creating a protective frost cover is well worth the investment. On newly established citrus or tropical species like the mango there are several options.

Building a frame and covering with plastic works well with a single kero lantern placed inside nightly. The heating is required if using plastic. Alternatively using canvas, a blanket or some other insulating material will provide good protection.

Hessian covers work well for temperatures of 0 to minus three degrees while the double insulated box is a great economical option providing protection well below minus two to three degrees.

Obtain two large cardboard boxes with one slightly smaller than the other so as one can fit inside the other. Between both boxes pack newspaper, underfelt, clothes or some other insulating material. This insulated box should be placed over the prized plant nightly and removed in the morning as temperatures rise.

The Japanese and Chinese make up thatched tepees and place these over their plants nightly, they also work extremely well.

All the above frost protection methods require the gardener daily to remove the frost protector cover in the morning and put it back in the evening.

Frost protector sheets provide a great alternative. These frost protector sheets can be put on nightly and removed during the day however as they allow 50% light though they can be left on 24 hours a day until the frosts are over.

Frost protector sheets provide a good alternative. These sheets can be placed permanently over select plants or particular garden beds. They provide frost protection while allowing 50% sun penetration during the day.

With the frost protector sheets I personally prefer to place them over frost sensitive plants at night removing them in the morning once temperatures have risen. I have trialed them both in the garden and in the nursery with great success.

For frost tender plants in containers these should be moved to warm protected locations away from particularly easterly aspects.

Place them in a northerly location or under the protective canopy of trees or physical structures. I’ve been bringing my chillies, whitewood and bean trees (both particularly sensitive to cold weather) actually inside when a frost is protected.

It’s most important to check the weather forecast nightly and take the necessary actions to provide the best protection for your frost sensitive plants.

Tomatoes in containers placed right up against a warm northerly wall of the house with a small over-hanging eve will provide enough protection to see your tomatoes continue to flourish over the winter months.

Likewise frost tender tropical plants even indoors should be moved away from windows as they can still be frosted through the glass.

In the vegetable garden a protective cover over the garden will give some protection, although most winter crops should be unaffected by frost. It is the out of season crops like tomatoes, basil and capsicums that will suffer. These definitely need some protection. 

On Thursday June 10 we experienced minus 2.2 degrees and many gardens coped a hammering. Tomatoes, egg plants and basil were three plants in the vegie patch that literally collapsed over-night where they were exposed while in some gardens they are still growing unaffected by frost, it’s all to do with location.

A light continuous spray of water over the vegetable garden just prior to and as the sun hits the vegetables will save them from frost damage. Don’t simply give them a light spray before the sun hits as the water you apply is likely to freeze and maybe cause more damage as the frosts thaw out when the sun hits the garden.

Remember it is not the freezing of the plants that does the damage, it is during the thawing out process that the damage occurs and the cell structure of the plants are ruptured.

In my nursery the automatic watering systems come on early morning around 7.30am just prior to the sun hitting the plants.

Moving air is another way of discouraging frosts from settling. Leave the outside patio fan on overnight or even place a revolving fan in the vegetable garden. It sounds crazy however it does work.

Frosts actually flow like water and will roll down and away from an elevated position settling at the lowest point or where they are blocked by a solid object.  

PHOTO: Bird bath? Bird ice rink!


Please enter your comment!
Please enter your name here

error: Content is protected !!