I am dividing my chrysanthemums and on all of them the lower leaves are black and narly.
It sounds like an infection! This can happen when conditions are too wet for the plant, and just right for infections.
At this point, I would treat with a fungicide before replanting.
Here is an article that will help:
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
This article will help you with the care of the plant:
https://www.gardeningknowhow.com/ornamental/flowers/chrysanthemum/growing-chrysanthemum-flowers.htm
A guy drove his tractor over my mums. Most are broken. Can they be saved?
If your plants are perennial, or "hardy" mums, they should come back. If you aren't sure, the only thing you can do is trim them back and see if they begin sprouting up again.
Here's an article for you:
https://www.gardeningknowhow.com/ornamental/flowers/chrysanthemum/annual-vs-perennial-mums.htm
on one plant all the leaves wilted - although still green. on the other leaves are still green but it's not growing at all.
They appear to have life to them, still. They are very heavily infected, so you may want fresh soil, but by the time that you change the soil they will be close to the end of their lifespan.
I would recommend starting with fresh soil next time around, and watching the water. Those cloth containers can be difficult to work with for most novice gardeners, and I would recommend using a hard container for picky Annuals.
Here is an article that will help you to grow these plants:
https://www.gardeningknowhow.com/ornamental/flowers/chrysanthemum/growing-mums-in-containers.htm
They, likely, won't be happy in the same container. I would plant them in a separate container, so that you do not have to lift the bulbs.
Here is an article that will help:
https://www.gardeningknowhow.com/ornamental/flowers/chrysanthemum/growing-chrysanthemum-flowers.htm
I bought some hardy mums to plant. When do I apply straw to cover the plant for winter?
You shouldn't have to cover them in zone 6 if you plant them in the ground and water them during dry spells. But if they are in a container or you just want to be sure they come back, you can cover them with straw or just mulch really well after a freeze or two.
https://www.gardeningknowhow.com/garden-how-to/mulch/mulching-plants-in-winter.htm
My daughter got this for me for my birthday in May and it had flowers..then they died and I cut the plant back and it got small but then I gave it miracle grow and took care of it good and it came back huge and then got buds but it’s been a couple weeks and they still haven’t bloomed
Garden mums often will bloom twice if cut back like you did. Some people cut the early buds off. They will still bloom if a freeze doesn't kill them first, though mums can take a light frost.
https://www.gardeningknowhow.com/ornamental/flowers/chrysanthemum/chrysanthemum-bloom-season.htm
supposed to freeze this weekend (like last year). Again, no blooms. So disappointed. What am I doing wrong? I'm considering just pulling these up and planting something else.
The first things that I could recommend checking will be soil pH and nutrient content. There could be a lack of phosphorus and potassium, or too much nitrogen in the soil to promote flowering.
Once you can rule those factors out, then you can begin to diagnose other issues.
Here are some articles that will help:
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soil-ph-plants.htm
https://www.gardeningknowhow.com/ornamental/flowers/chrysanthemum/growing-chrysanthemum-flowers.htm