The stalks are green at top and still white at base.
I have some bad news for you. You can not ever harvest celery seed from a lovage plant. Celery plants produce celery seeds and lovage plants produce lovage seeds.
Yes, celery can regrow after harvest if the base of the plant is left intact and placed in water or soil to encourage new growth.
Vegetable crops such as broccoli, asparagus, celery, lettuce, and cabbage are still harvested largely by hand.
When celery is ready to harvest, the stalks are typically firm, crisp, and have a vibrant green color. The individual stalks should be thick and about 8 to 12 inches tall, with a robust base. Additionally, the leaves at the top will be lush and healthy. Harvesting can be done by cutting the entire plant at the base or by selectively picking the outer stalks.
Celery is a noun. A sentence with celery in it is: The celery was mushy. A noun is a person place or thing. Celery is a thing which makes it a noun.
Lots of pictures of celery via the Related Link.
Celery is grown in the ground; the celery sprouts above the soil.
celery ! celery ! celery !
a celery stalk is one long big strip of celery
Celery does have roots.
Celery
Yes, you can substitute celery seed for celery in a recipe, but keep in mind that celery seed has a more concentrated flavor, so you may need to use less of it compared to fresh celery.