Space plants about 18 inches apart. When the flowers begin to fade, cut them all off at the base of the plant if you want to prevent them from self-sowing. Some flowers may appear sporadically through the summer, so keep your eye out for them - they make excellent cut flowers. In late summer, you can dig up a plant or two and put them in large pots to keep in a cool windowsill or light garden for winter harvests. Leave the pots outdoors until after a few frosts for best indoor leaf production.
Chives are easy to start from seed.
Start seeds indoors 6 weeks before the last spring frost. Set them out when the weather is mild. Or transplant a self-sown seedling that's emerged in your garden, or divide a mature plant. Renew older plants by dividing every 5 years or so. Use the fresh foliage with eggs, cream cheese, salads, soups, butters, and burgers.