Lathyrus azureus - King Tut Grass Pea
This rare blue sweet pea is extraordinary. Luminous blue flowers tinged with pink grow on bushy vines. They're scramblers, not climbers, and make a nifty ground cover between other plants. In a well-prepared bed they'll come up as a thick mass, smothering out weeds. The vibrant flowers are eye-popping.
Lathyrus azureus is native to India. It thrives in summer heat long after your spring sweet peas have faded. An annual, it will grow in any zone. It's been around for thousands of years. Seeds were found in King Tut's tomb. Really. They're extremely rare.
Plant them in a shallow pot or let them spread on the ground. They'll reseed themselves and you'll have more every year.