I am in Zone 4, and I do not know how drastic the change is where you are from z6 to z7, but is there a reason that you don't just mulch heavy and cover them up? When we have a plant out of our zone we generally just bury the sucker with lots of straw, leaves or soil. Is it necessary in your zone to bring them in? We do here if it is tropical (like zone 9 or 10) but otherwise no...curious if it is different where you are...cause that sounds like a pain in the neck...LOL...Helen.

If you want them to stay dormant, I would dig with as much soil as possible and leave it at that. If you shake off a lot of the soil, you're going to disturb if not kill some or a lot of the roots. Again, I'm talking about plants you want to just sit there, but survive the winter. If you're bringing plants indoors to grow through the winter then you would repot in new soil.

It might help to know which plants you're talking about. If you think you can get by with just a heavy mulch, that would probably be the best thing to do.

Kevin

Most are salvias and I worry that mulching will just make them more likely to rot when it's 60 degrees and rainy in January like it sometimes is here.
I was also thinking about digging up a couple lantanas, Cape Fuchsia, Cordyline, Illustris elephant ears, and another plant with dark leaves and glowing purple flowers that sort of look like penstemon or salvia blooms. It was in the annual section but I remember reading that it can be kept in the house over the winter. I can't for the life of me remember what it was called. It didn't bloom well in the heat but it looks awesome right now. Maybe someone will know what I'm talking about. The color is very distinctive. The flowers almost look like they have low-light bulbs in them. I planted mine in the shade so I assume it said shade on the tag when I bought it this spring.

I might try leaving one of my Illustris elephant ears in the ground and mulching heavily. I don't want to risk all of them though.

Plectranthus (Mona Lavender) was the other plant I was trying to think of.

You could take cuttings from the Plectranthus and grow indoors. These root easily and grow quickly. I've never had luck with letting the Illustris elephant ears go dormant. They just rot for me. Instead I dig them and repot in a much smaller pot. After that they go in a south window for the winter. The room is unheated in the winter, so the temps are often in the high 40's or 50's. When that happens, it's much better to keep the plant very dry otherwise the rot thing happens. I give it only enough water to keep it alive. Once warm weather arrives in the spring, these bounce back very quickly. I've also found you can grow new plants from pieces of the thick roots if they're in good shape. On more than one occasion come February, I realized some of my EE plants had succumbed to rot over the winter. I dug them up, found a few pieces of viable roots and salvaged those. Planted in a shallow tray and kept warm, they sprouted new plants.

Kevin

I had to look back at an old post to remember how I got Illustris through last winter. I let frost kill the tops, moved them into my garage until late February, then put the pots by a sunny window in my kitchen until it was warm enough to move them outside. I got a few sprouts but also a little bit of rot. Wish I had more windows on the south side of my house.

Hi, Christie
I live in east central Mississippi, probably about 200 to 250 miles south of you (which can, of course make a difference). I have an unheated basement. I bought a set of plastic rubbermaid shelves, and some cheap Lowe's shop lights. Hung the lights under the shelves using chains and S hooks, plugged them into a power strip and a timer. (Run the lights 16 hours a day.) Presto! A lighted plant stand for less than $125. (Get the shelves that are deep enough to slide the flats into sideways and you'll be able to light up 3-4 flats per level.)

In late summer, I take cuttings from my tender plants I want to save, get them rooted outside, and then overwinter them in the basement under the lights. I realize it may be too late in the season for you this year, but it's something to plan for next year, if you like this idea.

All that being said, here are some things to consider for right now. In my area, Illustris Elephant Ears are one of the most invasive plants I have ever grown. I used to dig them and try to overwinter them, and would lose half of them to rot. Three years ago, I told them to "Just Die Then!" and didn't dig them. By spring, I had them EVERYWHERE, and running through EVERYTHING. (Do you have whole ditches full of the plain green ones in your area? If so, my money's on the Illustris.) Since that winter, they have been relegated to big pots that stay outside all winter, and have to be taken out (a solid pot-shaped mass of roots, mind you), divided, and re-potted each spring. If you are in doubt, bring in a few, and leave a few in the ground. And remember, I warned you.

Lantana and Cape Fuchia are absolutely, positively hardy for me here, no matter how cold or wet it gets, as long as I don't cut them back until new growth emerges in the spring. I would think that you could mulch them heavily and get them through your winters, if you're not too far north of Memphis.

With Salvias, the problem is not usually how cold it gets, but how wet it is in the winter. If I were you, I would take one clump in for insurance, and leave the rest of them standing, but do NOT cut them back. The standing stems seem to give them insulation and keep them dry. Be sure your winter mulch is pulled a couple of inches away from the crowns, and if it gets really soggy, pull it back further this winter.

Plectranthus is as easy to root as coleus. Take some cuttings, strip off the lower leaves and put them into a glass of water. They'll root in a couple of weeks. Pot them up and put them in a reasonably warm, sunny window. They won't flourish, but they'll live. Then take them back outside when it warms up. Once they get growing, you can take more cuttings which will grow FAST throughout the summer. (In fairness, I have not grown the purple one you describe, but have grown several other varieties and all were equally easy to root.)

Hope this helps! Donna

Thanks for everyone's replies. Donna - Glad to hear the Plectranthus roots so easily. When I dug mine up a few days ago, there were a few pieces that broke off and I stuck them down in the pot in the soil. If they look wilty, I'll put them in water.
I don't see elephant ears growing wild in the ditches here. What a difference a zone makes. The plain greens have survived in the ground for me in the past, but they weren't the running type. Illustris is expensive here but getting a little easier to find than it used to be. You can send your extras north.
I have read that cape fuchsia may be able to survive in the ground here. I left one in the ground on the east side of my house to see how it does.
I intended to dig up a couple of my smaller lantanas, but I didn't and it got down in the low 20's last night. I may still dig them up and put them in the garage. They were ones I had winter sown so they weren't very big.
I still haven't decided whether my salvias would stand a better chance in the ground or in my garage.

christie, I have a salvia Black and Blue by the drive that is about 4 years old now. I just leave the tops on it and do nothing else except what leaves drift over it. It is about 4 foot across now. My salvia farinacias just self seed here and there so I never dig them up. I have a new red salvia this year and will just let it stay where it is. I also grow the really tall red salvia from Park's, spendens I believe. It also self-seeds.

How do I treat my Blackie sweet potato vine? I just pulled up the whole thing and cut it back and stuck it in water. Should I take cuttings or plant it or what? I do have grow lights on the back porch.

Sweet potato vine cuttings are easy to root in water and will root in soil too without treatment. I broke off several pieces and stuck them in a glass of water. I haven't had time to pot them up yet but will and then put them by a window. I kept a "potato" last year. It was several inches long. I just stuck it in my kitchen drawer and it kept all winter. I put it in a pan of potting soil and covered it about 3/4 and let it sprout this spring. I didn't look for potatoes this year though.
I planted three Black and Blues this year. They're still in the ground. I might dig one up just in case. I've had the species several years.