Crepe myrtles are street trees in my neighbourhood and right now our streets look dressed for a five-year old’s birthday party. The flowers are as frilly as a tulle tutu and come in a complete collection of princess pinks. That they manage to wear this exuberant frou frou and still look elegant is just one reason crepe myrtles are Sydney’s favourite small flowering tree. There are other reasons: in autumn they colour up nicely, bare branches in winter let the sunshine in; and the sinewy trunks develop fabulous silver, copper and bronze tones as they mature.
Selective breeding over the 200 years since the crepe myrtle, specifically Lagerstroemia indica, arrived in gardens from China has resulted in some outstanding varieties. But things really took off in the 1950s when Donald Egolf at United States National Arboretum began hybrising Lagerstroemia indica with the Japanese crepe myrtle, Lagerstroemia fauriei. The Chinese species tends to be badly affected by powdery mildew in humid weather. The Japanese doesn’t, but only comes in white with an occasional pink-blushed individual.
Putting the two together resulted in the Indian Summer series, more than 25 mildew-resistant varieties named for North American Indian tribes. ‘Natchez,’ for instance, is white to 8m; ‘Yuma’ is a pinky-lavender to 4m; and ‘Sioux’ is hot-pink to 4m. More recently dwarf varieties also became available (‘Chisam Fire’ is a showy dark pink to 1m) so that there are now some 120 crepe myrtle options to suit any garden need, from small shrubs to large trees.
Care questions revolve around pruning. Crepe myrtles flower on new wood, so pruning, which encourages new growth, results in lots of flowers. Unpruned trees will still flower, but with fewer frills. Some gardeners, and council maintenance teams, favour the hack rather than the prune, and simply blunt-cut the tree in what looks like one sweep of the chainsaw. This produces ugly thickets of thin upright growth.
A more pleasing approach is to selectively prune the tree to maintain a natural, elegant shape. Get the pruning tools out in late winter. If the tree has been grown on a single trunk, clear off any suckers or twiggy branches beneath the canopy. If it is a bit of a thicket, allow three or five main trunks to grow, cutting others out at ground level. Remove crossing branches from the centre of the canopy, clear out dead branches, then cut back anything narrower than a pencil. Make all these cuts flush with another branch or the main stem, so that after you have finished the tree looks like it has lost weight rather than had a bad hair cut.
The dwarf varieties are exceptions, some of which can get a bit leggy at their mature height. If that’s the case, give them a hearty chop to around 30cm above ground level in late winter, and they’ll shoot up in spring, ready to join the party in summer.
It’s time to
Keep a watch for signs of rust on frangipani, which shows up as powdery orange spots on the undersides of leaves. Spray with Ecofungicide before the infection sets in.
Tame Chinese jasmine
The long tendrils of new growth can be trimmed to keep a neat profile.
Still time for a harvest before winter if you act now.
Watch for lily caterpillars
These beasts will destroy a crinum or clivea clump with eye-watering speed. Squash individuals, spray hoards with Dipel or Yates Success Ultra.
The perennial borders at Sarah Ryan’s flower-filled country garden are at their best through late summer. The garden is open on 27-28 February and 26-27 March, at Yeltholme, which is just this side of Bathurst. Details: www.myopengarden.com.au