Frosty mornings are upon us. Sharply cold with gloriously blue skies. Slipped from those hot, hot days and nights to this? How does that happen and are you ready? Mostly we can be ready for winter in the garden by planting plants which are frost hardy. But, if you are like me, you occasionally just have to have that plant that is not quite as frost hardy as would be sensible….like the gorgeous white Crowea that I bought from Maria Hitchcock in Armidale. Obviously she also couldn’t resist it as her winters drop to -15 but you can bet that she, like me, has planted it in a spot in her garden where it is protected and perfectly happy. In my garden it is planted under the canopy of the olive tree and overwintered without a hitch last year so I’m expecting the same this winter. The other option of course is to plant such tender darlings in a pot and pop them on a warm north facing veranda.
Mature gardens will always have a variety of microclimates for such fussy plants but new gardens can be a little sparse on such positions. However Anigozanthos (Kangaroo Paws) are perfectly happy nestled up to a large rock which absorbs heat during the day and releases it slowly through the night or close to a fence which gives it protection. My Anigozanthos are just under the edge of the canopy of my stand of Exocarpos trees, facing north so that the sun shines on them all day but the frost can’t reach them at night.
At the nursery we do sell a few plants which are perfectly happy in the coldest nights as long as they have had time to mature a little. Like the Calothamnus quadrifidus green which I have just planted in an exposed spot. Yes I planted it two days before our first frost but I also made a little enclosure for it out of fencing wire with frost cloth over the top so it sits there warm as pie and will be ready for a massive growth spurt in spring. If it is anything like the Calothamnus quadrifidus grey leaf which I planted three years ago, and is now 1 ½ m high, it will have no need for frost cloth after the first winter. Grevillea curviloba subsp incurva is another plant which needs frost protection for the first winter but is then hardy. Such a worthwhile plant as it grows a meter a year. Mine is now 3 ½ meters wide.
Succulents can be extremely frost hardy. The native Carpobrotus is no exception. In the nursery we have Carpobrotus glaucescens with a green green leaf, bright pink flower and a vigorous habit and Carpobrotus rossii with a grey leaf, white flower and a quieter growth habit. However don’t water succulents over winter. They prefer to be less ‘succulent’ when it is frosty so that there is less water to freeze.
Winter is not a time to use fertilisers or prune plants either. Both promote growth and new growth is more liable to be damaged by frost. Save fertilising, if it is needed, for spring and pruning for after flowering and you will be safe.
Healthy, hydrated happy plants with good roots make plants hardier in adverse weather conditions. Spraying or watering with seaweed solution helps strengthen plant cell walls against both extreme cold and extreme heat but don’t water or spray plants after midday as the water on leaves or in the soil can freeze solid and damage the plants. In the past I have made the mistake of leaving plants to dry out in winter. The soil looks damp but most often is not and although plants need less water in winter because they use less in the cold they do still need to be hydrated if they are evergreen. So check down below the soil surface every couple of weeks (especially if the plant is young) and water if needed.
If you do find that a treasured plant has been damaged by frost try giving it a little extra protection for the remainder of the cold season and don’t cut off the damage till risk of frosts is over. The damaged leaves will help to protect the leaves further down the plant.
And no it’s not too late to plant new plants in your garden before winter sets in properly. The ground is still plenty warm enough to put young plant roots into. Notwithstanding that Iris and I both plant all the way through winter anyway. Of course we see what happens to the plants in the nursery on a good frosty morning so we know that what happens in the ground is not going to be near as severe as being in a frozen solid pot up on a bench.
So if you thought I was serious about hibernating by the fire through winter think again. I will be out in all weather tending various gardens round town and coaxing the roots on the cuttings in the nursery to grow, despite the cold, ready for you in spring.