They say 5-7 years until a ramp plant reaches full maturity. You can sustainably harvest small amounts well before then, though. Only the leaves, though. Ramp greens are my favorite part of the plant, and many are of the same opinion, so it's not that difficult for me to get to the point where I can harvest sustainably. I mayb already be there, actually. I did harvest about one serving's worth of greens this year! This was just before the plants went to flowering and they let their leaves die. At that point, you're actually doing the plant a favor by ending the leaves' lives in an instant. I have like 3 "mother plants" right now that are spreading via rhizome, and they are technically ready to have their roots/shoots harvested, albeit partialy for each plant. You take some of the roots/shoots, and replant the rest. Mother plants are hardy enough to take that kind of damage and then bounce back before winter. It can prevent a plant from flowering, though, so you have to be careful. If you're not gonna be somewhere long enough to reap all the benefits of a ramp-labor-effort, it can still be well worth it. Why you aks? Because you can TAKE ALL OF THEM WITH YOU wherever you go, lol! Seriously, though, you can do that. People fill up full pickup truck beds with their prized ramp stock when they move from one house to another, and then drive to the new house and transplant everything or nearly everything (the latter for if you are a nice person and you think the new owners will have a chance at keeping them going). Ramps are hands-down my favorite ingredient. Miso is also in the top 25. Same with morels. Asparagus, top 50. Cheers!
PS - I got some baby back ribs that I am smoking on the Weber today. I am gonna send you some pictures later.