oxalis crassipes ‘rosea’ - Pink Wood Sorrel USDA Zone: 6-9 Plants form a low mound of bright-green clover-like leaves, bearing a display of small, bright pink star-shaped flowers for months on end, especially in cool summer regions. Excellent in containers, rock gardens, or as an edging. Where not hardy, plants may be easily wintered indoors in a container. Clumps may be divided in early spring. Prune back hard in midsummer if the mound becomes untidy.