I'm a newbie with container gardening, so please bare with me.

I'm getting mixed signals from recommendations with what size containers to use with planting vegetables and how many plants to plant in each container. Also with where I live they don't specify the gallon size of the window boxes. All they give is the diameter of the rim of the window box in inches. This unfortunately fails to tell me how many gallons of soil the container can hold.

I do have the size in inches of the rim of the diameter of the window boxes that are available where are they live.

They are:

18" window box

30" window box

Can somebody please tell me how many gallons of soil these window boxes can hold? If you're asking how to provide this information to me, there is only one suggestion I can make. Based upon the rim of the diameter of the pot in inches, figure out how much soil the container can hold based upon how big the rim of the diameter of the pot is in inches. If this isn't feasible then can somebody give me a formula of some kind of how to figure out how many gallons of soil the container can hold using the size of the rim of the diameter of the pot in inches as a guideline? I've tried to figure this out, but to no avail.

The resources I have are a gardening pamphlet a pdf file from a website, and a website. I'm getting different suggestions and recommendations as to what size containers to use with each source.

With the pamphlet there are couple of problems, and they are:

With many of the recommended sizes it recommends the use of a 5-gallon window box. However it doesn't specify how many plants can be grown in a container of this size. On top of this it fails to specify whether only one plant can be grown in a container of the size they recommend.

The pamphlet recommends this:

Vegetable, Beans, Snap:

Container size-5 gallon window box (it doesn't specify how many plants can be planted in this container either, which just makes things MORE confusing)

Vegetable, Broccoli:

1 plant, 5 gallon container; 3 plants, 15 gallon tub

Vegetable, Cucumber:

1 plant, 1 gallon container (specifically it recommends a 1 gallon pot; will it make any difference whether I use a 1 gallon pot or 1 gallon storage container, or does this not matter, provided I use the right size container)

Vegetable, Eggplant:

5 gallon container (again it fails to specify how many plants can be grown in the container)

Vegetable, Lettuce:

5 gallon window box (once again fails to specify how many plants can be grown in the container)

Vegetable, Onion

5 gallon window box (again fails to specify how many plants can be grown in this size container)

Vegetable, Peppers (doesn't matter whether you grow hot peppers, or sweet bell)

1 plant, 2 gallon pot; 5 plants 15 gallon tub

Vegetable, radishes

5 gallon window box (again doesn't specify how many plants can be grown in this size container)

The other sites seem to be more reliable. They specify the size container to use, and they specify how many plants can be grown in each container size they recommend.

http://urbanext.illinois.edu/containergardening/herbveggie_vegvarieties.cfm

http://www.extension.iastate.edu/Publications/PM870B.pdf

My question is this. What source is the more reliable one, and which one should I choose to use as a guideline for planting vegetables in containers? As said before, I'm very much a newbie with container gardening. As a result, I don't know which resource to go by, as I don't know which is the reliable source because I have very little experience with container gardening. The whole point of making this post is because I need advice and input from people who have experience with container gardening.

I was just planning on using storage containers to plant my veggies in. I can drill holes in the bottom of them for adequate drainage. Also although they don't specify the container size in gallons they do specify it in quarts; I just convert the quarts to gallons and based off of this, I know what size container I need to equal the size in gallons. Is this feasible for container gardening, or would you recommend against this?

I am very much debating getting the supplies needed to plant some vegetables tomorrow, so I need advice and suggestions as soon as possible please. Thank you to all who post here.......appreciate time taken out of your schedule to post here. Also appreciate any suggestions, advice, input, etc. given; thank you for any advice, suggestions, input, etc. given as well.