The ornamental oxalis

The white form of Oxalis purpurea – the best of them all

Back in our nursery days, we had a large range of ornamental oxalis. I see in our old mailorder catalogues that we offered over 20 different varieties that we had in production at the time and I wrote extolling their autumn merits for several publications.

Twenty years on and the oxalis collection has refined itself down. It is the difference between gardening in containers and gardening in the soil. Some of those varieties were so delicate and touchy that we have lost them. Others needed to be kept confined because of their invasive proclivities. Some flowered prettily enough but their season was so short that it was hard to justify their place in the garden. I decided years ago that I was not going to fluff around with plants in containers. We have quite enough garden with many different micro-climates. If plants couldn’t perform in the garden, I didn’t have the time or inclination to nurture them in controlled conditions in containers.

These days, the oxalis we still have are the stand-out performers (and a few of the nasty weed ones that most of us battle – particularly the creeping weed which I think is Oxalis corniculata). The star has always been and still is the beautiful, well-behaved Oxalis purpurea alba. Large white flowers in abundance over a long period of time and not invasive. At this time of the year, I am more than happy to use it as ground cover in sunny positions. Oxalis flowers don’t open without the sun so they need to be in open conditions.

Oxalis purpurea nigrescens

O. purpurea is a variable species. The striking red-leafed form (O. purpurea nigrescens) with pink flowers comes a bit later and is invasive so needs to be kept confined. We also have a strong-growing (somewhat invasive) green-leafed form with very large pink flowers which is worth keeping and also has a long flowering season. Back in the days, I recall more than one person telling me that there was a red leafed form with the large white flowers but I have never seen it so I rather doubt its existence.

Oxalis luteola as runner-up in my best garden oxalis list

The standout yellow is Oxalis luteola. It, too, is well behaved and forms a gentle, non-invasive mat that flowers for a long time in mid- autumn, combining well without competing with other bulbs like the dwarf narcissi that are in growth but won’t flower until late winter and early spring. It leaves the rabbit-ear Oxalis fabaefolia in the dust for length of flowering time. Both have large, showy yellow flowers but the latter’s flowering time can be measured in days rather than weeks.

Oxalis massoniana

I am very fond of little Oxalis massoniana with its dainty apricot and yellow blooms but it needs a bit of nurturing to keep it going. The popular old candy-stripe O. versicolour is happy left to its own devices in the rockery but will not come into its season for a few weeks yet. It is the only one I know that looks more interesting when its flowers aren’t open because the striped buds disappear into a fairly ordinary white flower on sunny days.

I have hung onto the strong-growing O.eckloniana for its large lilac blooms but I keep it confined to a shallow pot sunk into the rockery. I could rustle up a few of the others from around the garden, like O.hirta in both lavender and pink, O. bowiei, O, lobata, the unusual double form of O. peduncularis  and O.polyphylla but they are not the star performers that luteola  and purpurea alba both are.

If you are into container gardening, a collection of different ornamental oxalis species give interest on a sunny terrace or door step from autumn to mid-winter. I saw somebody listing a whole range of different oxalis on Trade Me at one stage. In fact, it looked like somebody had bought our full collection all those years ago and kept it going so they are still around. If somebody offers you O. purpurea alba or O. luteola, don’t reject them just because they are oxalis. They are worth having.

Oh look! Here is a little display board I prepared earlier of under half of the oxalis that we used to grow

10 thoughts on “The ornamental oxalis

  1. SusanO

    I was lucky enough to acquire some oxalis from you – and beautiful they are too. – the candy stripe versicolour is my favourite. I love its long flowering season and the stripe on the furled up flowers – so dainty.

  2. Maureen Sudlow

    Oxalis has long been thought of as the gardeners curse. I spent months clearing them from a flower garden when we moved into this house, but we loved seeing them on the wild hillside where we came from – used to call them four-oclockers because the little flowers closed as the sun started to go down. And of course I love yams that come from the same family

  3. Kiyel Candy-Boland

    Hi Abby,
    I have a huge collection of Oxalis around 70 species and varieties. I was wondering if you had copies of your old Plant list , just to see if there are any that you had that have been lost.
    I will add a link to my on line photo album, and the Oxalis albums. I have a small nursery, and grow other weird and wonderful plants. I have been in Horticulture for 50 odd years . I did
    my apprenticeship with Napier Parks and reserves, Back when they’re apprenticeships. Spent most of my time in the nursery learning propagation. Love your blog and wait for it to come each time.
    Well dinner time, heres the links.

    1. Abbie Jury Post author

      Goodness! At 70 different species and cultivars, you must be line for claiming a national collection. What is the blue one you have photographed? Is the image colour accurate? Never seen a blue one. Our oxalis list never went on line and I don’t think I have the original files on computer – just the hard copy archive.

  4. Kiyel Candy-Boland

    Hi Abbie, i think it could be “Mathew Forrest” a hybrid between O. lacinata and O. enneaphylla, One of the South American Alpine species. Has long gone out of my collection. Not the easiest to grow. There used to be a few of these in NZ. Ione Heckler was one. I know of one collection bigger than mine.There used to be quite a few Oxalis, when i started collecting in the late 60’s But all the little specialist nursery have gone. we still find an odd one in old gardens now and then :)

  5. susurrus

    I never realised how varied they are. The leaves, for example! Even the ‘weedy’ ones brighten up a lawn in my eyes.

  6. tonytomeo

    Oh, I know they are pretty, but this group reminds me to much of their wickedly invasive counterparts. You know, I can tolerate and actually like most eucalyptus, despite the bad reputation of the blue gum. Yet, oxalis still worries me.

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