Ewen's garden

A collection of columns, paintings and photographs about gardening on an offshore island in New Zealand.

Monday, February 20, 2006


In my last column I wrote asking for the identity of a plant from my garden. I am pleased to report some one responded and have now come up at least with a genus to which the plant belongs. Thanks to Marion Robertson of Palm Beach Lodge, we believe the plant in question is an Oxalis sp. Unfortunately I am unable to clearly identify the exact species, my RHS dictionary of gardening only lists 52 of the 800 odd species belonging to this genus! Even using the botanical key, an accurate identification wasn’t possible, the closest being a species native to Chile and Peru. The genus is widespread geographically, being largely found in South Africa, tropical and subtropical South America, but there are species belonging to almost every region on the planet! A successful plant if ever there was. At this point I imagine many are now throwing their arms up in the air with horror at the mere thought of oxalis being mentioned as anything but a weed. I have to admit there are some of the genus which do have a bad reputation. To name two: Oxalis
latifolia and O.corniculata. O.latifolia a native from Bermuda, Mexico and south to Peru, is the dreaded weed proliferating via the plentiful little bulbs which form around the top of the rhizomatous root. Any part of these if left behind in the soil will grow making it almost impossible to eradicate once ensconced in the garden, I know I have it growing here in my own garden. The other O.corniculata, native of Japan, is a creeping plant, similar in habit to clover, though the flowers are distinctly different, yellow and the foliage red. I have spent many hours in the past, weeding this character from a thyme lawn in the music department of the Auckland University!

It is a pity the whole genus gets tarred with the same brush, as certainly only a small portion of this genus are truly weeds. The specimen I have is tolerant of drought has attractive foliage, and hasn’t showed any signs of spreading wildly. Another ornamental species is the candy stick oxalis O.versicolor. This species has small white flowers that when in bud have a red stripe curling around them giving the appearance of a candy cane. The whole plant is diminutive in stature only growing to about 20cm in height. I recall with fondness this wee plant from the rock garden on the farm.

Should I comment on the ARC plans for adding such plants as Agapanthus to the banned for sale list? Well it would seem the horse has already left the stable! I would have to ask whether the dwarf cultivars are really noxious weeds? I do agree, it is probably not necessary to sell the common blue and white forms as they do seed every where and if you are desperate to have some, it is not usually a problem to get some from other people’s properties. As for the Bangalow palm, Archontophoenix cunninghamiana native of Northern New South Wales and southern Queensland, I would like to know where it has become naturalised? I have seen it growing profically in Alberon Park, Parnel, but never in bush. Maybe council should look more closely at controls of existing weeds. At least be more specific about exactly which species of a genus is to be banned, and whether it is to include cultivars and hybrids of the same genus.

Happy weeding.


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