Not sure but sounds like Aphids to me. They will be almost like a mushy mass on the leaves and the rolling up of the leaves seems like a classic sign of them. I get them on my Evening Primrose.

Aphids can cause a leaf at the tip of a plant or shrub to be distorted and curled, but not rolled. They also do not eat holes in anything, they have the wrong mouthparts for that. They pierce the plant and suck out plant juices. The description sounds like a leaf roller, although even certain types of spiders (a beneficial) can roll up a leaf for protection. But, I suspect you have canna leaf rollers, and here is a link to a page describing them.

http://creatures.ifas.ufl.edu/orn/L_canna_leaf_roller.htm

Could be aphids. Might be spider mites if you notice some webbing used to curl the leaf to provide shelter for eggs. You're in zone 7? It also could be greenhouse white flies. They like fruit and veggie plants. Look for little yellow eggs on the underside of leaves. Adults cut and suck the juice out of leaves leaving them limp and susceptible to disease. It's hard to say with symptoms crossing many possible culprits. Inspect with a magnifying glass if you got one.
I'd spray leaves with a fine blast of water in the morning and mix a mild batch of soapy insecticide and hit 'em with that. If you have a serious infestation hit 'em with pyrethrum or rotenone. There's a recipe for soapy insecticide here. Scroll down till you see "make your own..." Love to hear how this turns out for you.

Here is a link that might be useful: The Little Green Apple-Pest Control Pages

To re-emphasize -- aphids don't make holes. Nor do mites. Nor do whiteflies.

But caterpillars do.

Mite damage doesn't create mush. Nor does aphid damage. Nor do whiteflies.

Instead of spraying to get rid of the caterpillars, squish when the leaf is rolled. Sprays won't reach them because they are protected by the leaves.

Or ignore the holes because they will be a very minor blemish in a few leaves.

As for "The leaf is a brownish color at the base of the leaf, with virtually no strength, and it seems soggy. The brownish color does not take over the leaf...just a three inch area at the base."

That's due to something else entirely. (But what I don't know.) None of the above mentioned critters had a hand in it.

Can you post a picture?

Leaf Rollers, the larva of one of several insects. The most effective control is to squeeze the leaf and squish the wee bugger in the rolled up leaf. The very broad spectrum poison Malathion, something that should only be used as a very last resort (if ever) was not effective because it did not get to the problem. Since these larva are layed as eggs on the leaf surface putting down somebodies slug control was inappropriate also.
Good, effective pest control starts with knowing your pest and then using the appropriate control, but starting with the least toxic means there is.