AS I write this, suddenly autumn has arrived with blustery, bitterly cold winds.
Until the second week in April, autumn was magic with unseasonably warm days and nights. It simply could not last forever and this is the very beauty of Canberra with our four seasons. Although on occasions we do get the four seasons in one day!
Discussing this with folk who recently moved here from North Queensland their comment went like this: “At least when it is cold you can put on extra clothes, but with the sticky tropical heat there is only one way to get cool, sit in front of an air conditioner. In tropical gardens, one sees the same old evergreen plants year round, whereas every season in Canberra provides a refreshing change”. A good reason to live here.
Many perennial plants are continuing to flower. One of the most interesting illustrated here is Sedum “Herbstfreude” or more commonly known as Sedum spectabile “Autumn Joy”. This is an unusually tall succulent, which grows to 100cm tall with numerous interesting aspects.
Firstly, the pale green, almost white flowers appear in late summer on thick, tall stems. Then, as autumn approaches, the flowers turn to a pale pink, gradually changing to a bronze and finally a deep burgundy colour.
They remain like this until the first frosts, which will kill the top growth. This is the time to cut the plant to ground level. Now, the amazing part of the story is those new, little shoots will start growing almost immediately in winter and are not affected by frost. By spring, the leaves will be almost 30cm tall and together with the flower stems will attain their full height by late summer, by which time the process starts all over again.
After a couple of years they can be divided into a dozen or more new plants. Plant in full sun and this will grow in the poorest of soils, even gravelly soils. The white variety is a little harder to find, although in my opinion this is not as spectacular as S. “Autumn Joy”.
IT is spring-bulb planting time, but what about the autumn-flowering bulbs such as Nerines? If planted now they will not flower until next autumn, 2011. However, I noticed Heritage Nursery in Yarralumla have potted these up early in the season to enable you to enjoy the flowers over the next few weeks. When they have finished flowering, simply plant in a sunny spot in the garden where they will rapidly multiply over the coming years.
A REMINDER that autumn time is feeding time and one important plant nutrient to apply to all plants now is seaweed liquid plant nutrient. Besides all the benefits of more than 60 trace elements and, more importantly, promoting root growth, it builds the plant’s resistance to frost by lowering the temperature at which plant cells freeze. I recommend giving all your plants an application of seaweed without delay before the frosts start in earnest.
I ALSO recommend that pruning of evergreen shrubs is completed before Easter, which is late this year (normally no pruning after the middle of March). After pruning, the soft foliage underneath will be exposed plus if we have a bout of warm weather after pruning, new shoots will rapidly start to grow. A few snap frosts and this young growth will be badly effected.