ALLIUM TUBEROSA is a very sturdy herb and very easy to grow with very little care, once established. They taste great....like garlic cooked in cream. They are very popular in Asian cuisine, as much a vegetable as an herb. They grow in expanding perennial clumps and readily reseed themselves. In warmer growing zones, they're evergreen. Mine rarely freeze back, and I've seen them covered in ice. In colder zones the tops die off, and they resprout in the spring.....and come up from seed they've dropped the previous season. If space becomes an issue, keeping the flower stems "dead headed" just after the blooms drop and before they fully develop their seeds, will drastically limit their reseeding and help to keep them in check.