We wake to a cracking frost this morning. We have had a few good ones these last few weeks. It’s neither good nor bad, it’s just what it is. The frost has killed off every soft and vulnerable plant in the garden that were struggling on through the cold weather and short days. Plants like basil, just turn up their toes at the slightest hint of cold, quite early on in the season. The first really cool shift in the weather makes them lose a lot of their leaves. The next cold snap, especially if there is a cold wind with it and they are gone till we replant them in the spring.
Tomatoes hang on a lot longer, but the first light frost or near frost makes them lose their leaves. Funnily the lingering un-ripe fruit isn’t affected and can be brought into the kitchen and ripened on the window sill over the next few weeks.
Nasturtiums and capsicums seem to be able to tolerate a light frost and remain intact, although not exactly thriving. However, this mornings beauty has put an end to everything that was gamely battling on. This spells the end of the lingering autumn stragglers.
What is great about a period of good solid frosts, is that they benefit the plants that have excellent frost tolerance and even rely on the freezing to establish the ‘chill-factor’ chemicals in the new growth that will emerge as fruiting buds in the spring. Some varieties of fruit trees need a good chill to become fertile. All the older varieties of plants like apples, pears, the stone fruits and particularly hazel nuts, need to get a hundred or more hours of below 4oC temperatures. If they don’t, the flowers cannot become fertile in the next growing season. A few years ago, we had a winter here without frost and didn’t get any fruit set on any of the apples or pears.
Hazels and filberts have slightly different origins, with one being rounder and the other more ovoid. Filberts have a longer skirt on the outer shell. They both seem to have originated in Asia minor/Turkey, but have been developed into stronger and more prolific bearers of larger nuts over the long period of domestication.
Hazel/filbert nuts are reliant on a high number of cold nights to establish their chill factor chemistry. A lot of work has been done on breeding local varieties of low chill factor nuts here in Australian in the post war period. In Australia, we just don’t get the sort of winters that are common in north America and Europe. However, we just happen to have a hazelnut farm research station near us here in the Southern Highlands.
We have been able to buy grafted varieties of local hazels that have been bred to fruit in warmer low chill areas like here. We have these low-chill fruiting hazel/filbert nut trees inter-planted in the nut grove with others that are inoculated with French black Perigord truffle fungus. We are hoping that the spores will spread to all of the other hazel/filbert trees at some time in the future.
A good bit of cold weather really helps to colour up the citrus and sweetens the Brussel sprouts. In the mean time the frost looks great on the surviving plants until the sun comes up and melts it away.
The sun shines and the days are glorious, as long as there is no wind.
When the weather changes and the wind blows off the snow. There is no frost but the days can be bleak. When we came here, the locals described it as a lazy wind. It doesn’t blow around you, but rather, straight through you.