Heaving - is that what they call it?

Five crunchy frosts in a row.  On the morning of the first of them I was forced outside to see what I could do to get some hot water out of the frozen (brand new) hot water service, and while out there, went to check out the crystalline flower heads on the miscanthus, and the white caps on the sedum.

The gravel underfoot was crazily crunchy.  Walking on it was like dancing on bubble-wrap.  It’s texture was entirely altered, with sweeps of it appearing curiously raised.  Looking up close, each particle of gravel was held aloft on clusters of fine threads of ice, like glass enoki mushrooms.  I can’t even begin to imagine by what mechanism or action such ice crystals form.

As the sun rose, individual pieces of gravel just dropped, quite suddenly, back into place.

Addendum – after publication, found this ref, should you want to know more about ‘needle ice, as it’s known.  Should have looked from the start…


  1. Hi Michael,

    I am only too familiar with this phenomenon! I used to wonder what on earth had created a whole new landscape across my winter bulb beds. It looked like some tiny creatures had come out under cover of darkness and “re-worked” the surface creating little dales and hillocks where before there had been none. So it wasn’t fairies at the bottom of the garden after all!

  2. We think it’s cold here on Mt Gibraltar but we haven’t had a frost yet. We’re on the warm side of the hill, but even Bowral hasn’t suffered from the cold – only ridiculous amounts of rain. I loved your description of the crunchy crust but don’t envy your freezing conditions! Keep warm.

    1. Actually Meg, the freeze is the best of the cold. I’m coming to understand that as long as I can take some measures to minimise the frost damage, or can organise a good spot to store plants over the winter, then I could really love the crystalline carpet and milky, desaturated colours of the background trees on these mornings. Much rather that than leaden skies and chilly winds.

  3. Hi, I am a newcomer to your lovely website! I am so jealous of your recent frosts. We have only had a few this year and seem to be getting an unusual amount of cloudy ‘Melbourne weather’. And it is lovely seeing such a celebration of cool climate gardens and plants. Most of the info that is generally circulated is for temperate climates (eg so much talk about lilly pillies and murrayas, which we can’t grow here! Give me a viburnum any day).
    Re your hot water tank, I am hoping you haven’t installed a heat pump hot water tank! Here in Canberra I had one installed a few years ago (a Dux Airoheat) but it just didn’t work – the top portion was continually frozen (literally iced over) and the unit spent all day trying to defrost itself instead of actually heating water. We never got more than tepid water from the thing, and it still ended up being more expensive to run than our old off-peak tank. It appears that these heat pump hot water units are not suitable for frosty climes as the air is never warm enough for them to work optimally. If you do have one of these, I suggest exchanging it ASAP whilst under warranty.

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