Does placing an empty 1 liter milk carton (with both ends removed) around the celery help it to grow straight and intact?
Yes, it will. It will also help to blanch it and make it more mild flavored (which is often desired). Milk carton covers are a common thing for celery growers.
I planted celery in my elevated garden. Someone told me you have to put something around it so it grows straight. What do I put around it to grow properly?
Here is an article or two that you may find helpful: https://www.gardeningknowhow.com/edible/vegetables/celery/tips-on-how-to-grow-celery.htm
https://www.gardeningknowhow.com/edible/vegetables/vgen/raised-vegetable-gardens.htm
I am growing celery, and it is doing well. Do I need to do anything to get it to bunch up, like tie it or something?
With celery, all you really need to do is blanch it to prevent it from becoming too bitter. These articles should help: https://www.gardeningknowhow.com/edible/vegetables/celery/tips-on-how-to-grow-celery.htm
https://www.gardeningknowhow.com/edible/vegetables/celery/learn-about-blanching-celery-in-the-garden.htm
I know certain vegetables can be grown in a container pot, but can celery be grown in a container as well? (I was given several celery plants). Thanks for any info you can help me with!
You can try, but celery is temperamental in the first place. Make sure you keeps its roots cool as best you can and keep it well watered.
I have grown some really nice looking celery, but when I cut some off, it was bitter and some of the stalks were not solid. Can you help?
This may be of help to you:
https://www.gardeningknowhow.com/edible/vegetables/celery/tips-on-how-to-grow-celery.htm
We have celery in this year, it's about 100 days in. What do you suggest for keeping the bunch vertical and compacted?
Cardboard milk cartons (top and bottom cut off) work great for this. And they blanch the plant as well. You can also use hair bands, like the kind that a person would use to put their hair up in a pony tail.
In what part of the celery plant does it store food?