They can grow up to 2 feet (60 cm) tall. They are best harvested, though, at any height before they reach 8 to 10 inches (20 to 25 cm) tall. When cut at that height, they may be sold in markets as “garlic scallions.” Beyond that height, they can start to get papery.
Particularly, you want to harvest the tips of the leaves.
Some varieties of garlic will focus energy more than others on producing green tops rather than on producing underground bulbs.
Garlic Greens have a very subtle garlic taste: stronger than chives, milder than cloves of garlic.
To grow your own, separate cloves in a garlic bulb, and plant the cloves 2 to 3 inches (5 to 7 1/ 2 cm) deep, upright in a pot. There is no need to peel the cloves. The cloves should produce sprouts in 4 to 8 weeks. Harvest a few leaves at a time to allow for continued production. After harvesting, you will get up to 2 additional batches. To keep a continuous supply, you may need to plant new cloves every 3 weeks or so.
Garlic Greens are not the same thing as garlic scapes or garlic chives.
Chop up and use as you would green onion or chives. Snip into salads, mix into cream cheese, garnish soups, add to fresh vegetable juices that you are blending.
Green onion and peeled garlic cloves, both chopped, in the quantity you deem appropriate.