The plants don’t survive winter in Zone 6, but in warmer climes oxalis can quickly become a weed. Purple oxalis as well as red-and-green iron cross strains are hardy only to Zone 7, but several species can survive much colder winters. Species that do not make tubers (for example, O. vulcanicola) are especially bad about throwing seeds where they are not wanted.
http://www.barbarapleasant.com/oxalis.html
House Plants. Purple shamrock (Oxalis triangularis) is a houseplant in cold winter areas. In USDA zones 6 through 10, it can grow outdoors in borders or edgings. Purple-leaved plants do best in light shade and moist soil. White or pinkish flowers contrast well with the dark leaves. Volcanic sorrel (Oxalis vulcanicola), hardy in zones 9 through 11, has several colorful-leaved cultivars.
http://homeguides.sfgate.com/oxalis-annuals-perennials-64642.html
It grows in U.S. Department of Agriculture plant hardiness zones 7 through 9. Violet wood sorrel (Oxalis violacea) comes from bulbs in USDA zones 5 through 9. White, pink, lavender or purple flowers bloom in spring, with repeat bloom possible in fall.
http://homeguides.sfgate.com/oxalis-annuals-perennials-64642.html
This woodsorrel is typically grown as a houseplant but can be grown outside in USDA climate zones 8a–11, preferably in light shade. The subspecies O. triangularis subsp. papilionacea, in particular its cultivar 'Triangularis', is highly popular as a pot plant and known as love plant and purple shamrock.
https://en.wikipedia.org/wiki/Oxalis_triangularis
They will also grow in light shade, but will produce more flowers and leaf color will be more brilliant in stronger light. Consider potting a few bulbs for indoor enjoyment; perfect in a sunny windowsill! 3. Dig little holes and plant the bulbs 1”-1.5” deep from the top of the bulb and 3”-4” apart.
http://growingguides.com/PlantGuides/oxalispurpleshamrock.pdf
Oxalis triangularis, commonly called false shamrock, is a species of edible perennial plant in the Oxalidaceae family. It is endemic to Brazil.
https://en.wikipedia.org/wiki/Oxalis_triangularis
San Antonio, Texas. This plant does well planted where it receives morning sun and afternoon shade or filtered shade in my area. Compared to the pink oxalis I have planted, it withstands the summer heat better and is bloomimg profusely after 108 degree weather.
http://davesgarden.com/guides/pf/go/1241/
Have had plant and it's babies about 15 years, gift from grandaughter for St Patrick's Day. Have under trees and does well even in the dry Texas heat, if given ample water. Have one in container outside that gets a lot of attention from neighbors. It is such a lovely compact ball with its pink accents of blossoms.
http://davesgarden.com/guides/pf/go/1241/
Barbara Pleasant: Indoor-Outdoor Oxalis. If you want an easy houseplant that produces plenty of pretty flowers and lots of drama, oxalis, commonly called shamrock plant, should be on your list. Oxalis in any color can't wait to start blooming in late winter. Purple shamrocks have pinkish flowers, with white flowers more common on green shamrocks.
http://www.barbarapleasant.com/oxalis.html
They are thriving very well. About 3 years ago I added the green Shamrock to the bed & last year I added a new one I had never seen before. It has green leaves with the deep burgundy in the center. It puts out the palest of pale pink flowers, a definite difference to the white & dark pink of the other two.
http://davesgarden.com/guides/pf/go/1241/
what zone does purple shamrock grow
The purple shamrock grows in USDA zones 6 through 10. Purple Shamrock grows in the United States Department of Agriculture zones 6 through 10.