A gallon pot for the Rosemary should be fine. Unless it is AARP you will need to bring it in over the winter to keep it alive, so you don't want too large a pot if you have limited space to do that.

Depending on the kind of mint, you could easily use a pot two feet wide. Most mints will overwinter outside (you will need to look up your particular type), so you will not have to carry its large pot inside for the winter.

Dill is tall and will reseed, and parsley is a biennial, so planting in the ground might be better for them unless you have a very large container for them, such as a whiskey barrel.

The soil and other filling you use in your pots will determine how heavy they are, even if you use the new lightweight ones.

I usually throw some pebblelike material on the bottom (actually, sometimes, bark mulch pellets, which have at times failed me as far as drainage goes) and then some partially composted, or even freshly gathered, fallen leaves, sticks, etc. to half fill a very large container--that way you are also composting while you are potting, but this does not give the best results--If you purchase your potting soil, a large pot can use quite a bit of it.

I have sometimes used bagged topsoil when my other gardening activities have not generated enough soil from my own property. It is no good for tiny plants, though, due to possible soil funguses.

Sometimes you will see pots that are very wide but short. Those can be good for a mixed planting of the smaller perennial herbs like thyme and rosemary, but would frustrate most mints.

Parsley has a long tap root that must be accommodated and so needs a deep pot.

WHen it comes to herbs there is no pot too big.

Thanks for the info!

Eibren, what if I were to put mint in a shallow container all by itself? Would it still have a hard time?

I can't wait to start harvesting and cooking!

Like fish, herbs will only grow as big as the container they are grown in will allow. Except mint will grow out of the bottom if the width becomes to small. I found this out when I sowed parsley and the seedlings in the small pots never got bigger than a couple of inches but the seedlings transplanted into the garden grew large. Same thing for the dill. But if the pot is too big, I wouldn't pot any of the above in anything larger than a one gallon or 6-8" across pot, you are just going to be watering alot more. Remember if you find the plant is out growing the pot you can always repot into a pot 1-2" larger anytime.

Hi GC, I agree with everything Karen said--I'm not certain what you meant by shallow, though--if you are placing the pot in the ground and it is too shallow, the mint will just grow through the hole in the bottom and you will have perennial mint. If you have it up on something, you could try it just for interests sake.

One possible exception as far as escaping goes might be chocolate mint; I have found that to be rather delicate in my zone, in the locations I've tried it in so far.

Anyway, a typically-formed pot would probably be better for mint.

I had a thyme do fairly well in a shallow container for several winters, though.