I just removed a dwarf alberta spruce and planted the flaming silver pieris that you see. Also planted some calla bulbs that you see but flowered poorly (not enough sun?) Beyond that not sure, I could just edge the bed with hydrangeas or perhaps grasses like hakone? The roots around the arbor vitae make it hard to plant there but there was a geranium and a rose that survived there (until this year). I would like a full lush look but not sure if thats even possible under the lilac? Should I avoid planting up to base of lilac?

For a nice texture contrast, you could edge with sedge (rhyme not intended...) or Liriope muscari, I like the effect of ferns against grass-like foliage. Or ferns or grass-like foliage with bergenia. Bergenia is a t-o-u-g-h plants, and I love the textural effect of the cabbage-like leaves, which are tinged with red in the fall. Fill in with some annuals in the summer.

Just a few of lots of possibilities...

As for how close to a lilac - I have plants under the drip line but not right up against the tree. I wish I could tell you what variety I have but unfortunately these came from my mother-in-law and she could not remember what they were.

Once you have 1-2 hydrangeas planted, you can fill in with others such as hostas and heucheras on the side where they do not get too much afternoon sun, and day lillies where they get afternoon sun. If you want to fill in quickly, get 1 or 2 big hostas (saw Hosta Winter Snow at our Home Depot today. These grow fast like their parent Sum and Substance). They also have some ones with fragrant flowers.

Vivian

Not a hosta lover and the ones I do have seem to be eaten by some critters. I have two pots of silver oats grass, I haven't planted yet. Might put these in with some hydrangeas as suggested. The variegated liriope might also be a great idea to edge the bed.

Its not too dry because there is a sprinkler in there somewhere. Never tried ferns, brunnera or bergenia so this might be a good time for it.

I don't think that I would want to introduce many other kinds of plants regardless, such as both hydrangeas and liriope. My preference would be for one kind of groundcover to tie things together, perhaps one of the short all green Leucothoes which would echo the pieris in leaf texture or Microbiota decussata which would sort of echo the foliage texture of the arborvitae but provide winter color contrast. Alternatively, a low-growing groundcover that will provide a background to your 3 featured plants might work, particularly if you could use it in other beds to provide some tie to the rest of the garden. I have Veronica 'Georgia Blue' growing in a mostly shade garden under a lilac. For most of the growing season it provides a delicately textured background, with a couple weeks in spring when it's a river of blue. It's shallow rooted and doesn't seem to bother any of the plants it wanders around and doesn't need deadheading or any other care.

The microbiota decussata is a fascinating plant. Never even heard of it before. I have lamium white nancy around the base of a JM in another maple and it makes for great contrast. Was also considering planting something in a row along the brick wall of patio along with current plan of planting mainly along outer edge of bed.

Also would like to use variegated plants if possible.

I have a combo of the Variegated Solomon's Seal, surrounded by Bergenia (Bressingham something or other), fronted by some purple heuchera and an almost totally silver pulmonaria and a painted fern in a similar spot to yours on the northeast corner of my house.

I like to tuck in a deep pink or red impatien here or there after I clean out the area in the spring for some summer color. The bergenia has lots of reddish color in both spring and fall (it gets smashed down by snow in winter in my climate, but always surprises me by popping its big leaves back up early each spring). The Variegated Solomon's Seal can take awhile to mature, but makes a very stately impressive planting in a few years.