The first and only thing that came to mind is a Alternanthera. It is an annual. I used in when I first started my garden for splashes of color. It is a beautiful foliage plant that everyone always asked about. Not sure if youre interested in an annual, but I don't know of any other plants this color other than maybe coleus. Although they may be hard to find....nurseries are more apt to carry them.

Here is a pic, not sure if this is the color you are seeking....

How about sedum Xenox? I don't grow it, but it looks perfect for your needs.

(I actually grow "Purple Emperor" and it is too tall for you. Mine doesn't normally splay in the middle and I've had it for years. It does tend to travel around a bit though.)

Here is a link that might be useful: sedum Xenox

How about Husker Red Penstemon? A bit taller than you asked for but not too tall.

Ohhh Debbie those look perfect. Would be a beautiful accent!

I appreciate all your ideas and will look into them further. I'm intrigued with the annual "Alternonthera". Thanks all!

Been looking for Alternonthera. So far, can't find it locally.

Been looking for Alternonthera. So far, can't find it locally.

I think you should consider the purple heucheras. There are quite a few purple ones and they'd make an excellent edging. My favorite is 'Midnight Rose' - this is not a very good picture, but this is one in my garden:
{{gwi:240236}}

I like the lime green heucheras too but I've never got one to survive the winter! None of my purple ones have ever had a problem with winter survival or frost heave.

I have some of the purple heucheras, but they are in more shade than sun. I didn't think they'd do well in full sun. What is your experience?

All my Midnight Rose and other purple ones (Chocolate Ruffles, Crimson Curls Rachel and others whose names I don't know - gift from a neighbour) are in the full sun front garden and are thriving there. I do have Palace Purple in the backyard in shade. There is a green one in the front in full sun (companion to a Silver Mound artemesia!) that also does fine. Heritage Perennials site lists Midnight Rose and others as 'Full sun or partial shade. They probably like more shade in hot zones but full sun seems to suit them fine in zone 5.

Here is a link that might be useful: Heritage perennials - Midnight Rose heuchera

Thanks, I'll look into it. I do like my coral bells!

It's interesting that heucheras are so closely associated with shade. I just used the Advanced Search function on the Heritage Perennials site to search for heucheras for full sun in zone 5 - it listed 61! Some of the ones I grow in sun aren't on that list but still do fine. Clearly these plants are more versatile that most of us assume and some further experiments with them are in order! I have often thought lately that it would be nice if heuchera breeders spent some effort to breed for larger sized leaves/clumps in the ones that will grow in sun. Wouldn't you love to have a plant with the ground/weed smothering big-leafed density of a hosta, but with the color range of heucheras and able to grow in full sun?! I'd certainly buy a bunch of those!

Here is a link that might be useful: Heucheras for sun - per Heritage Perennials

Thanks all. Heucheras it is! Now to figure out which variety.....

I've been looking at the varieties suggested by woodyoak. My question is, which of the ones which are purple/reddish and do well in sun will not fade badly when in the sun? There is mention of Palace Purples fading in the sun. Your experience?

I have a few Midnight Rose heucheras in about half sun / half shade. The sun, even though it is morning sun, is surprisingly hot. The heucheras do fade, even in the half day sun. They fade to a speckled, very pale, purplish green. Nowhere near the nice deep purple they start out as.

As a matter of fact, from a design standpoint I needed another Midnight Rose - or, at least, another purple plant - to fill an empty spot, and after much hesitation, I just bought another MR today. I hesitated because I know it will fade and not be the purple I need. But I broke down and got one today, because a) I'm not sure what else to use and b) it's just so darn pretty (when it's purple!)

Dee

Interesting - I don't find that my Midnight Rose fade at all in full sun. This is not the greatest picture but you can see a couple of them here in the 'moat bed' along the ditch by the road. {{gwi:240237}} One of the things I like about them is that as the clumps get bigger over the summer it makes the ground look rich and dark. In this picture (pardon the messy dying tulip foliage!) you can see how well the purple ones (different - unknown - variety) stand out against green. You can also see one of the green Bressingham ones in the moat bed strip (there's a matching one just out of the picture on the right - they partner with the clipped Silver Mound artemesia and pinks.):
{{gwi:240238}}

The only purple one that has failed me is 'Obsidian' - and it was at the back of the front bed, where it got shaded by the garage in the afternoon. It just sort of faded away.... I think it, and some of the other purples, actually NEED sun. I bought a Midnight Ruffles today - it will be going in a full sun location too.

Palace Purple heuchera does fine in full sun 8 hours in Summer here two zones higher for years now - as long as it isn't allowed to go dry. Find it keeps its color without fading till the cold sets in, when it becomes burgundy. The leaves brown out during mid-late Winter some years, dissolve on their own by early Spring & grow back lushly. Needs good drainage in the Winter wet here & fairly rich woodland-type soil.

Another you might consider is Salvia lyrata. That does keep its purplely leaves here all year round, can take moderate drought & grow in any soil, sun or shade. Bought it as a native years ago & planted it in a previously hopeless spot next to the driveway. Did so well & looked so fetching, started trying it elsewhere. Originally concerned it would reseed with abandon, have not found that in the last 12 years. Foxgloves reseed more gleefully here. Pleased with a few trialed as an edging, moving volunteers to form one now.

The flower stalks give a similar impression as the heucheras, but are less showy, a bit more substantial & more enduring. Bees, butterflies & hummingbirds like them. If you want no reseeding, clip the flower stalks before they dry. Even left to dry & fall or be eaten by finches, reseeding not a problem here. Seedlings easily relocated or pulled, as are mature plants. I've become very fond of them. Well behaved & don't crowd out companions.

Mine looks most like Purple Volcano due to its closed flowers, rather than Purple Knockout. The foliage has a velvety appearance.

Here is a link that might be useful: Salvia lyrata

This post was edited by vasue on Mon, Jun 9, 14 at 12:33

Googling Salvia lyrata purple over lunch, seems mine may be Purple Knockout, as the flowers look just like this example.

Here is a link that might be useful: Salvia lyrata Purple Knockout

And just to clarify (not) the hardiness range, this source says 5-8...

Here is a link that might be useful: Purple Knockout