Chives usually grow up to about a foot tall. You can start cuttin a few of the leaves, but not all from each plant. If you cut off al the leaves to he soil level that will stop them from growing further. Chives grow well in the summer, while the type I grow here are a winter variety (actually a wild onion). Mine die out in the heat of summer, but send up a small round ball of tiny bulbs once the leaves die out I crumble and spread into the nearby soil. In mid fall, the greens start to sprout again, and I harvest just a few greens each time I need some. The taller the greens, the bigger they get in diameter. Mine are about an 1/8 inch in diameter and a few can reach up to 3/16 inches if the are really big. Giving them only three weeks of growing isn't enough time. I would wait about 2-3 months before harvesting any.

Rule of thumb is to start harvesting at any time you have enough to use, plus leaving 2/3 of the plant remaining.

My chives thrive in the blast of summer, and die down to almost nothing in our subtropical winter.

THank you both for the advice! I guess I'll hold off on trimming the chives.

I regularly trim young chive plants back to only a couple of inches from the top of the pot (three fingers). I direct sow seeds in 2 1/2 inch pots, about 30 or so per pot. Once they get so tall that they begin to droop under their own weight, out come the scissors and the whole plant gets cut back as described. Assuming that your plants are otherwise healthy, you should be able to harvest at least a half inch off of them now. No need to pick individual leaves either. I do the same thing with lettuce, parsely, dill, and cilantro. I loosely adhere to the 2/3 rule for woody herbs like rosemary.

I am doing my first garden and i was wondering if you are supposed to harvest chives before they flower and if they had already flowered if they are still good? They were here from the old owner, so i don't know what kind they are.

I use my chives before and after flowering. Before the frost, I chop 'em down and cut 'em and freeze 'em. It's all good.

Chives that are fresh have the most flavor. Freezing and drying them, you loose a lot of the flavor. Store bought ones i8n jars are usually freeze dried and seem to have a bit more taste.

You can eat the flowers too! Makes for a beautiful salad :)