Beware of Blue Morning Glory!
Rampant, smothering and hairy - if only blue morning glory was as ugly as it sounds. But unfortunately, as with many good plants turned bad, this is an attractive plant that escaped into the wild by first wooing its way into our gardens. Blue morning glory is a tropical perennial climber with three-lobed leaves (hairy underneath) and large, trumpet-shaped bright blue/purple flowers. It is banned from sale, distribution, propagation and display in New Zealand.
Why is it wicked?
Gardeners beware! Blue morning glory is a member of the Convolvulaceae family and is worse than the average convolvulus, bane of many a gardener. Blue morning glory grows higher and reproduces more quickly, particularly beyond the garden fence. It takes root from fragments and grows aggressively in scrub and bush where it smothers native trees and shrubs. It produces very little seed in New Zealand, so much of its spread has been from dumped garden waste.
What can you do?
Be very careful with the disposal of this plant because it will grow from broken pieces. It is best to take it to a green waste station for heat treatment. Smaller infestations can be pulled out by hand, but take care to remove all roots. Large infestations can be cut down but the re-growth must be sprayed with herbicide. Thick stems need to be cut and stump treated - click here for more information on control options.
Instead of blue morning glory, you could try growing the native clematis, puawanaga (Clematis paniculata) which has a mass of showy white flowers during spring. Alternatively, purple coral pea is a twining climber with purple pea-shaped flowers and will provide a great splash of colour.