Most of them are already growing in my garden or are waiting permanent homes in pots. The problem isn't going to be trying to figure out what to plant, but figuring out what to leave out.
Since I probably won't check on this new garden every day, the plants need to be tough guys who can survive and thrive without a lot of babying. Most of my garden is like that. I have only a few beds and borders, near the house, where I put my "pets" and plants that need special care.
I'll also want plants that spread and cover ground. If I don't cover the ground with plants of my choice, Mother Nature will do her best to cover it with something. And her choices are generally real thugs.
Just about any reasonably tough plant that spreads by roots, rhizomes or seed can be considered a groundcover. Groundcovers don't have to be low creepers. Some plants cover ground at an amazing rate and are best used in relatively rough areas. Some plants are very difficult to eradicate once you let them in, if the conditions suit them. If you put them in less than ideal conditions they are better behaved. Nevertheless, you need to think seriously about introducing them in the first place so that you don't have to spend years cursing yourself while you try to get rid of them. Campanula rapunculoides, Polygonum cuspidatum,Houttuynia cordata 'Chameleon', Mentha (Mint), and Aegopodium podagraria 'Variegatum' (Variegated Bishops Weed) all fall into this category because they spread by underground roots. To my mind, this makes them more difficult to remove than plants that spread by seed. Still, invasiveness is relative. One person's bane is another's pride and joy. Just make sure you research new plants before planting them in your borders so that you will know what they are capable of under ideal conditions.
Pachysandra
For shady areas, probably the first groundcover that comes to mind is Pachysandra terminalis (Japanese Spurge), rated hardy from USDA zone 5 south. I have quite a bit of it and it does its job very well. It demands shade; is not picky about soil; tolerates dry shade and root competition and stays neat and tidy all year around. It even has a white flower in early spring. You can't ask much more of a plant. On the other hand, too much of it can be a bit boring. It has already gotten a toehold at the end of the West Border and I think I will leave it at that and keep an eye on it so it doesn't take over too much space. There is another variety of Pachysandra, actually two -- one is a form of P. terminalis -- P. 'Variegata', with leaves variegated in white, that is not quite as rampantly robust. I lost the one plant of this that I had by letting it get swamped by other plants. I thought it would be as tough as the species. I may try it again in this new garden. The other is Pachysandra procumbens (Alleghany Spurge), rated hardy to USDA zone 4. This one, a native of the southeastern states, is not evergreen in the north. I haven't grown it yet, but it sounds interesting. Its flowers can range from whitish to purplish and appear before the leaves in spring. The leaves are a slightly different shape than P. terminalis and it is more clump forming.
