Growing your own plants from seed is less expensive than purchasing new seedlings each year. You can save even more money while ensuring you have your favorite vegetable seed available by saving your own seed from your garden plants. Celery is one vegetable that you can successfully save seed from if you plan ahead. Celery is a biennial, so it doesn't produce seed until the second year after planting. Celery usually sends up a flower stalk once temperatures drop below 40 degrees F in the second fall after planting, but occasionally it will send up flowers the first winter.
Leave some celery plants in the garden after harvest so they can produce seed. Watch the plants for when they bolt, or send up the flower stalk. The stalk reaches up to 3 feet high and has light green, feather-like flowers.
Pick the flower stalks once the petals have withered and when the stalk begins to dry. Spread the picked stalks out on newspaper in a warm, dry room so the seeds can finish maturing.
Hold the flower stalk over a shallow bowl. Break open each seed head with your fingers, releasing the small seeds into the bowl. The seed heads are located directly beneath where the petals were when it was flowering.
Store celery seed in a jar or an envelope. Label with the the seed type and the year harvested then store in a cool, dry place until you are ready to replant in spring.