Turbans usually have 5-7 very large fat cloves that form something of a circle around a center that may or may not have a scape. There are few or no tiny interior cloves.
Turban garlic's bulb wrappers are usually very colorful with lots of purple splotches and stripes. Some cultivars are very white but vividly striped with red/purple vertical lines.
Most of the Turbans I have grown have had stalks (called scapes) that form an upside-down U before straightening up. All cultivars of a given variety of garlic generally have the same scape pattern before they straighten up; all Rocambole scapes form a double loop while Purple Stripe garlics form 3/4 of a loop. Asiatics have a smaller seedhead (properly called an umbel) while Turbans have a larger umbel that resembles a turban. The umbel is covered with a membrane called a spathe and the pointed end of the spathe is called a beak. Turban garlics usually have a beak in the range of 6 to 9 inches or so and have the second-longest beaks of all garlic varities. Not all have scapes but most usually do. Turbans have 30 to 100 small rice-size bulbils in their bulbil capsule.
Some cultivars are instantly hot to the taste while others may be remarkably mild for up to half a minute before you get a very hot taste that spreads from the back of the mouth forward. They can be very pungent and have a musky aftertaste.
Not all Turbans are hot although some are but there are also some rich garlicky ones that don't overpower with pungency.
Asiatic and Turban Varietal similarities
Asiatic and Turban garlics were originally classified as a separate group that was part of the Artichoke garlics but recent DNA research done independently by a couple of Garlic is Life colleagues of mine, Dr. Gayle Volk of the USDA in Fort Collins, Colorado and Dr. Joachim Keller of the Institute for plant Research in Gaterslaben, Germany, shows them both to be weakly-bolting hardnecks that are distinct from each other as well as the other groups of garlics.
Asiatics and Turban garlics have as many similarities as differences. Asiatics have 8-12 fat cloves, Turbans have about 6 really big cloves. Asiatics have a few pea-size purple bulbils whereas Turbans have 30 to 100 pinkish rice-size bulbils.
They are the very earliest harvesting of all garlics and if you can grow them you'll have garlic before anyone else is anywhere near ready to harvest. They are short storing garlics as most don't last more than 5 months at room temperature before sprouting. They are always the first garlics to sprout in the fall.
They are also unusual in that they don't mature gradually like all the other garlics; when they are ready, their tops start to fall over, like onions. That's too late. The time to check their bulb size and get ready to start harvesting them is in mid-spring before their leaves fall over and they lose all their bulb wrappers, as they will if they stay in the ground for very long after they are ready to be harvested.
If they lose their bulb wrappers, their storage time will be reduced even more than usual. The secret to success in growing great Asiatic and Turban is to dig down and watch the bulbs develop and when they get big enough to suit you, go ahead and dig them up, don't wait for them to fall over. You simply have to harvest them before they fall over.
They do seem to grow exceptionally well in dry climates like the southwestern USA, if properly irrigated.
Asiatics and Turbans should be a part of every garlic lover's garden along with long storing ones so you can have fresh garlic all year around.