I have this strange succulent something that appeared early last spring (it must have hitched a ride in annuals the year before) that is evergreen and has lacy white flowers. It is kind of invasive, but it DEFINITELY keeps the weeds down and my perennials don't seem to have any trouble pushing up through it. If you're anywhere in the north Seattle area you're welcome to swing by and pick up a few shovelfuls of it.

You can avoid extra work by planting shrubs instead of non-woody plants. A carpeting shrub could form the ground floor and then so on up from there. There are also herbaceous perennials that produce mats of evergreen leaves, you can easily see many of these adorning old Seattle rockeries during spring flowering times. Now is a good time to look for these in smaller, cheaper sizes at local independent garden centers.

Also important to get the structure of the terrace right before doing planting. The front edge of each terrace level needs to be a very well-anchored, solid substance like wood or cement (steppers or edging pieces). The terrace partitions should stick up an inch or two above the soil behind them.

Trying to do it with bare dirt or a mosaic of small pieces will eventually break down and erode to the original slope. Planting shrubbery with strong root systems will tend to push the partition pieces forward, past vertical.

How much does this 8-foot long section slope?

There are numerous perennials & woody plants that have evergreen foliage & even bloom in winter whether in sun or shade, so it won't have to be bare in the winter.

If you post a photo of your site & determine the lighting (how many hours of direct sun & what times of the day) as well as soil condition (clay, sand, etc.) you could get specific suggestions on this forum. The slope is important, too as suggested above.

All groundcovers spread to overtake an area which is why they're called groundcovers. They will help stabilze the soil once established. You can plant pockets of colorful annuals or perennials that fit your idea, but will have to fight back the groundcover around them.

Depending on the site a colorful 18" or wider pot of mixed perennials & annuals might be the burst of color you're looking for & much easier to just leave the area planted with an evergreen groundcover that needs no fussing.

If I had a choice I wouldn't create an annual planting bed on a slope. Our experience with a sloped garden at a family member's home has been too much work!

We've been helping a parent get a long sloped garden area established after it became unsafe for him to continue to mow on the slope and he decided to start planting things in the grass there instead. After the grass was taller than his plants and we weren't sure how to mow around the starts, we dug out all the plants out & built a garden bed over the grass lasagna style. It's now a mixed perennial (very few herbaceous) & shrub garden on the top with mostly evergreen groundcovers on the most sloped area at the bottom that once established will only need some light trimming in early spring or fall clean up. Weed pulling, planting, mulch spreading... bending over, leaning, keeping your balance, getting up & down, etc. adds up to too much work taking the fun out of gardening.

I am so glad we don't have sloped gardens here & won't do it again anywhere again.

Well, I had some of the same wishes when I was putting in/redoing our garden out front. We had vinca out back and it seemed to do lovely. Hadn't really spread much, so I put it in the yard about 3 years ago. BIG mistake. The vinca I bought went CRAZY, sent suckers EVERYWHERE, actually was inhibiting the growth of several bulbs I'd planted over the years. I believe it was the soil I put it in, a lot more light and with more nutrients than what we had out back. I just ripped it out last weekend, in the rain, it was lovely, but I will NEVER make that mistake again. You need to be able to weed through and around it, and with the amount of suckers it puts down, it makes it impossible. So, keep that in mind when you think of groundcover. Have you thought about maybe putting in some evergreen flowers or shrubs to help take up some of the slack? Here are the names of some of the stuff I have in my yard that seemed to stay evergreen this last season. Papaver (poppy) Manhattan and Beauty of Livermere, a peach colored poppy, any variety of thyme (though, it will spread too, but it's easy to pull some out, or divide). Hellebores could also be lovely, dependant upon the amount of sun you get. Morning sun works fine for them, and they stay green and can grow quite big, they can also hold their flowers for almost a year, so, there's that too. They usually flower right around January or February, usually right around Lent (which is why their other name is Lenten Rose), and are wonderful. You could also do some evergreen blueberries, as long as they'll get enough sun - sunshine blue is a good variety for here. You could also plant some crocus blulbs in the fall to come up in early spring. You could also do something with some lovely winter interest such as the yellow or red twig dogwood shrubs. I have a red one and it is amazing in the winter, especially when there's not much else to look at, the red twigs are really pretty. If you're wanting an easier go of it, these are my recommendations. I could not believe the incredible mess that my groundcover made! Good luck!

I should have also said, if you are thinking about putting in terracing, these plants could be quite nice. That is what we did in our yard last year. Corrine was right about the slope, do you know what the grade is?

How about some ferns? They are evergreen, hardy, and they don't need any care other than some cleaning up now and then.