What are you growing? If you're sure that species needs to be pulled, you would pull them and place them in a shady DRY place with air flow to dry. Make sure the individual bulbs have enough air flow to dry evenly. Scapes on cloving alliums isn't a problem. You just tend to get smaller cloves... Onion types are a different matter, from what I learned from experience. If the plant grew a scape early in the year and continued growing leaves, the scape tends to get pushed out to the side and the bulb will still cure ok... If the plant grew the scape late in the year, close to harvesting time, the bulb wont store well and will have a hollow scape hole down the middle. I usually don't harvest bunch onion bulbs or walking onion bulbs, since I only use them for greens. The young scapes are good for cooking though. I usually leave a couple though if I want seeds or bulbils...

If you're referring to the ornamental alliums, there is no need to dig them up unless you want to move them to a new area.

Rodney

Zone 10 takes a bit different management from those of us in colder climates. Best to see your local arboretum or extension agent or find a local master gardener in your area to ask about this. If you are growing types that need cooling to flower you will probably have to lift them and do the cooling prior to planting.

A lot also depends on which alliums you are growing, too.

Depends where you are and exactly what kind of alium you were growing. There are a thousand different species of aliums, and a million cultivars. If the alium you grow isn't hardy in your climate (can't take the cold) then you would have to dig them up. There are also Mediterranean bulbs that get confused and rot if they aren't in a place with dry winters, and bulbs that need to be chilled in the winter to bloom. Personally, I don't dig up aliums, I leave them in the ground. Generally I figure anything that can't overwinter in my area is too much trouble to grow...but I'm in Zone 6. I think aliums can generally overwinter from Zone 3 to 9. I'd think you would want to leave them in at least for the summer so they can soak up energy with their leaves.