But if you missed the window, you can plant Allium stipitatum this month for a pink summer display. ‘These ornamental onions give a tremendous display and are easy to care for,’ says Nicky.

pink, red, white, and yellow and can be successfully grown in USDA hardiness zones 4 through 9. The flowers are globe-like and appear on tall stems and can reach a height of around 3 feet. Allium ...