Coreopsis 'Moonbeam' is slightly taller than 6-8" but would suit your 'pale yellow flowers' & other conditions--foliage is lacy/delicate and feathery + it's drought-hardy. Also, 'Helen von Stein' (aka 'Big Ears') lambs' ear is a non-flowering, non-spreading cultivar I've enjoyed the past few years that has year-round appeal with minimal maintenance. I don't water much of anything other than astilbe & hydrangea since it isn't practical so I try to plant things that thrive on neglect but which attract bees, butterlies & hummingbirds.

Thanks for the suggestion of "Big Ears", Gardenweed. I had seen this plant at a couple of garden walks last summer and wondered what it was. It looked so much better than my lamb's ear plants, which I plan on taking out this year. Maybe I can find one of the Big Ears at a garden center this year.

Thanks Gardenweed, I have C.Moonbeam in a driveway Daylily bed and it works well. I even looked to see if I could find seeds to spread this workhorse a little faster and cheaper. no luck so far. I have Helen Von Stein in the large back garden. I am slowly replacing the Lambs Ears with Helen as she increases and I can have devisions. She is a bit too wide and stout for the problem in the raised beds.There are some pretty redish Coreopsis that would be nice but there is a hardiness problem. The hunt continues. In the end if I can't find a new choice I will work on getting some more C. Moonbeam.

Wren - C. Moonbeams spreads with division quite well, and if there are any plant exchanges in your area, you might get some there. I often see it fairly inexpensively at some of the nurseries near me.

Another suggestion that I have found has done well for me in droughty conditions, but doesn't seem to mind some moisture in winter is Penstemon pinifolius, pineleaf Penstemon. I have tried a couple different varieties from High Country Gardens and they have survived well so far in an area that's on a steep SW facing slope that gets no extra moisture other than what mother nature provides. I mulch them with gravel. Different selections have different heights and they seem to be red or yellow. Mine have retained foliage all winter.

You could also look at some of the western Agastaches, which come in various shades of pink, apricot, red, and purplish. Don't cut them back until spring, and mulch them with gravel also since they don't like water sitting around their crowns in winter. Gorgeous in summer, but not too ornamental in winter.

HCG, which carries all of these, is currently getting reorganized after having to close their brick and mortar nurseries, but you can get on their email list for when they have their online catalog up and running. You may get other ideas from their catalog since they specialize in plants with low water needs.

Here is a link that might be useful: High Country Gardens

Thanks NHBabs, I have ordered from High Country Gardens in the past. Good to know that they will stay in business. I grew Penstemon Mystica in that bed before. It was too tall and overpowering. I moved them to the back garden. Love them but they were too happy in that bed,lol. I will look at the Pinitolius varieties you mentioned and the Agastaches too. I may, in the end, Have to thin the Daylilies and make it more of a mixed bed,ouch.