Plants tell us a lot with their leaves. In the case of garlic, they tell us when the bulb is ready for harvest. Or do they?

Scanning some of the literature written by expert growers, we saw differing opinions on what harvest signs we should be looking for:

Garlic is mature when the tops fall over (mid July to early August).
-Eliot Coleman, Author of the Four Season Harvest

When half to three-quarters of the leaves turn yellow-brown, it's harvest time.
-Organic Gardening Magazine

Each green leaf above ground represents a papery sheath around the cloves. Once the leaf tips begin to yellow and die back, its time to dig the garlic. The lower six to eight leaves still being fully green indicate optimal harvest timing: This allots 5 to 7 protective wrappers around the bulb after curing. Our harvest here in northern New Hampshire begins the latter part of July and gets completed by the first week of August.
-Michael Phillips, Heartsong Farm

It's time to harvest garlic in the late summer when the bottom two or three leaves have turned yellow or the tops fall over.
-Ed Smith, author of the Vegetable Gardener's Bible

Harvest in summer when the bottom leaves are beginning to yellow and before more than one or two leaves turn brown (July through August).
-University of Wisconsin Cooperative Extension

Fully green, yellow, or brown: so who's right? Well, in a way, you could say that all of them are. It depends on what your garlic goal is. The longer you wait, the larger the bulb. The danger in waiting too long is that the bulb will start to split apart into individual cloves. If Michael Phillips urges an earlier harvest when the plant is still upright and showing a lot of green, it's because he has a different goal: long term storage. An earlier harvest helps insure that the garlic cloves are "well-wrapped" for fall and winter feasts.

One surefire way of knowing whether your garlic is ready is to dig up a test bulb. If it's a decent size and seems well formed, then you can harvest the rest of your crop with confidence.