In nature plants are typically in groups, so that's not going to make it look formal. Perhaps just plant the groups irregularly, instead of in a pattern, and allow the plants to spread and take their place more freely. Of course, more variety in plants could also help with a natural look.

I'm in awe of your stonework, jugglerguy. And envious that you have easy access to suitable stone ... and the strength to move them!

I recommend you make random groupings of the different groundcovers. Three ferns here (odd numbers are always better than even), a wedge of geranium there, etc. The areas for each groundcover should not be the same size or shape, and it would be best to avoid straight borders.

The area extends over such a large area that you could have more than three groundcovers, particularly if some are similar: for instance, you could have different small ferns, not simply the Japanese painted fern, and count all the different ferns as a single groundcover. You could have different tiarella cultivars with different coloration -- but the same basic leaf type, flower spike, and growth pattern -- and count all the tiarellas as one groundcover.

But please re-think the vinca! It will take over -- probably send runners through the joints in your wall, too. First you'll have vinca growing over and through the other plants, then it will overwhelm them. At least that's my experience with vinca here in 7a. Even if it doesn't completely choke out the other groundcovers, I don't think it will be the look you're after.

I have a ton of vinca here, but mostly used alone as a groundcover under shrubs, sort of a living mulch. It does grow into neighboring gardens, but not real fast. I chose it because it's free, it's dark green, which contrasts with the other two plants, it will cascade over the wall, and if a bench gets backed into it or someone steps on it, it's pretty tough. I want something below the wall that won't grow high enough to completely cover it. The geranium will cover about a foot below the wall.

On the other hand, I might have to pull out more vinca if it's mixed in with other plants. I'll think about it.

The other problem with vinca is that it's ugly, though I would reject it just on the basis of its spreading; you're quite right that this is a matter of respecting the space of other plants, but it is also about your rocks. If you or a future owner ever want to remove the vinca (which most people who grow it eventually do), it will require demolishing your wall. I suppose I'm just paraphrasing MTO above here, but for me the bottom line is, why spoil gorgeous rock walls with such an undistinguished plant? Not only is it ugly, but also, it is capable of hiding them completely.

If you're determined though, then I think the trick would be not to mix the vinca with anything else; make masses of each plant alone, and try to keep the vinca away from the rock. Especially, though, I wouldn't try to get the Japanese painted to compete with the vinca. What you'd need is something like the Robust Male fern or Dryopteris cristata to absolutely bust out of the mat of vinca. The poor little JPF wouldn't have a chance.

But if you were open to other ideas? First, I'd just mulch, because any groundcover is going to take a while to grow in, and mulch will limit the weed problem until then. Second, I'd look into creeping shrubs: Juniper MotherLode, Salix yezo-alpina, Picea... it think it's glauca St. Mary's Broom and many more as an alternative to the creepers - the conifers forum can fill up the list.

But then, among the creepers, even for this big an area I'd go for the polite ones - just divide up your pots so you have several patches growing to start with. Aubrieta (I've got a white flowering and a variegated one that are very well-behaved, and just two years after planting are really filling in nicely), saxifrages (strawberry geranium for instance), dianthus (there's a great little one with cerise flowers). I mean, I'd look at it this way: it's a big area and you'll really notice what's there. It might as well be nice.

There are some stachys; even the common silver one is really a pretty good plant. In fact, if you want one that is capable of the kind of coverage you'll get from vinca, then I think stachys would be one of my choices.

Nice to see you're still working on your rocks and enjoying them; I haven't been in the stone forum for a while.

KarinL

I don't think vinca is ugly, I guess it's subjective. But yeah it's not the best companion plant.

Lamium may be another option for a couple of reasons, the silver on the plant will grab the light and it tends to flower a couple of times per season. It would contrast well with the ferns. By the way very nice area you have created. You should enjoy this for many years to come.

Wow, lots of opinions! Thanks.

Karin, you really have some strong feelings about vinca, don't you? I'm listening to the opinions here, but I have to defend vinca a little. First, I like how it looks. It's certainly not the star of the show, but it's a good filler around shrubs. I like shiny leaves. I'm really not worried about it destroying my wall. I killed a whole big area of it once with Round Up because I couldn't control the horse tails (Equisetum arvense). It wasn't hard to kill.

{{gwi:44313}}

I like how once you get in established, it's pretty carefree. As you said, it does crowd out other plants. When I first planted it, I incorrectly thought it would choke out existing plants. I worked for years trying to pull grass out of it. In other spots, I pulled out weeds and grass several times during the first season and it was very little work. I've never intentionally planted vinca with other perennials, only with shrubs, so I could be making a huge mistake. I'm definitely reconsidering.

I forgot to mention another big advantage of vinca. I grows in sun or shade. My new garden ranges from full sun to full shade, so it would be something that would unify the area. I'm not familiar with all the plants Karin mentioned (I'll look them up as soon as I'm done writing this). Would any of them do well in shade? Storm, I do have several types of lamium that I could move to that area that would do okay in shade, but they haven't been quite as reliable as vinca has been for me.

Another plant that I've considered is Canadian wild ginger, but the deer sometimes eat it and it doesn't spread very fast. When I asked my wife's opinion (she's not the gardener) she pointed to a tiarella and said she liked it (as missingtheobvious suggested) so I'll use some of that. The reason that I was keeping my plant pallet small was to keep maintenance to a minimum. I have other gardens with much more variety, but they seem to take more work to keep up. I don't want to overdo it and regret having so many gardens.

{{gwi:49900}}

Thanks for all the comments. I know I stuck up for vinca, but I am listening and definitely reconsidering it.

Oops, Karin, I forgot to ask you if you have any pictures of how you used the plants you mentioned in your gardens. If so, could you post a couple that might be helpful for my situation? Thanks.

Juggler, I realize photos would be a logical accompaniment to what I wrote, and I'll try... but I will say my gardening scenario is way different from yours - my whole lot is about the size of your firepit, house included (OK I'm exaggerating but you get the point). So stuff is crowded, hence my areas don't tend to photograph well. I'm also a little pressed for time...

My main intent in posting, as with others I think, was to make sure you didn't naively plant vinca but know its true nature. I admit I never thought of roundup to kill it if it gets out of hand; that might help. And if you like it, more power to you!

And what ground covers I like may not match what you have available. So my advice is, basically, shop and try other things. Ginger is another good choice, and I would think the odd deer grazing might help keep it in check - once it grows in, it is pretty feisty. It is surprisingly tenacious and may also grow through your rocks. Anything stoloniferous will. That's why plants that form mats on top of the ground would appeal to me more in your shoes (ps I also picked up a little Juniper called Pancake yesterday - that would be an idea too). Lamium, for my taste, would not work here; too rangy. At least Vinca forms a mat.

To go back to your actual question, arrangement, I'd agree with your basic idea. Your area is not symmetrical, really, so you don't need symmetry, but maybe think about balance and keeping the eye moving around the area, so you want repeating patches. Your shrubs have a bit of the formal in their placement, so your ground covers can de-formalize a little bit by crossing boundaries from one shrub to the other.

KarinL

Only one shrub is actually in the ground, so I'm still playing around with the placement. I try to plan for their full grown size, and some are pretty big, so it limits how close I can plant them to the retaining wall.

I got some bad news the other day. The flag stone that I'm planning to use on the patio was supposed to be available this fall. I just found out that it's not going to be available until spring. I've been working on this thing all summer and was really hoping to get it done by fall. Bummer.