The frost are about to descend upon Robertson, I predict.
How do I know?
Simple - my Tree Dahlia has started to flower.Regular readers may recall two similar posts, from two years ago (OK only dedicated readers will remember these posts). I link to them, for more recently joined-up readers.
The first was entitled "The optimistic nature of Tree Dahlias", published on 7 June 2006.
The second was "The Nature of Frost (and an update on Tree Dahlias)" published on 13 June 2006.
The message is clear. Tree Dahlias take so long to grow to their full height, before they flower, that, inevitably, frosts are just around the corner. This year's flowers are about 2.5 metres above the ground. The plant grows this tall every year, before it flowers. Then the frost kills all the soft tissue material of the plant, leaving only the root stock. As with normal Dahlias, the plant has a set of tubers in the ground which are the perennial part of the plant. The difference for the Tree Dahlias is just how far they have to grow before the plant is mature enough to carry flowers.
In truth we have already had a very light touch of frost - but only once, and only very, very light. I do not know the temperature, but it was not enough to count as a real frost. Just a few signs of ice crystals glinting on the roof of the car.
But real frosts cannot be far away. Get your "Winter Woollies" out of the cupboard (if you have not done so already).
Tree Dahlia growing in front of native Sassafras and Pittosporum trees. The Sassafras (taller tree on right) is about 15 metres high. The low shrubs to the left of the Tree Dahlia are all well over head height.
Cultivation note: Tree Dahlias are easily cultivated by taking a stick of the stem with two growth points (nodes). (A stick about 15 inches long, usually). This will resemble a piece of fresh sugar cane, if you have ever seen that. Lie the stem down on a shallow angle, (bottom end first) so its head is just above the potting mix, in a Styrofoam box filled to the top with potting mix. Water it, and leave it alone for about 3 months in a protected position, and when you look at it (next spring), it will have formed roots on the bottom, and new shoots at the top. Plant it out and wait for a year. My plant came as "cuttings" from a friend in Canberra. I did exactly what I have described above, and my new plant has flowered every year since. Even though it is a silly plant to grow in a cold climate, I love it for its dogged determination to prove it can survive and flower each year.