Where are you located? Is the planter box mostly sunny/partly sunny? Width and Depth?

What state are you in? What climate zone? What direction does this face- north, south, east or west?

Does it have a sprinkler in it or will you be watering?

What is going on with that big patch with no grass?

Will put grass this week. i live in canada - zone 6a. house is facing north. I will be watering it. No automatic sprinkler

The box is mostly sunny

Size Approximately 19’x2’ I think

I'll take Canada zone 6a to be the same as merica's 6a. I have not heard otherwise.

Fill the bed with two kind plants - Cephalotaxus harringtonia 'Prostrata' and a short to medium height selection of Joe Pye Weed, Eutrochium purpureum. Done.

I agree with loobab. I would not only put perennials because for 7 months of the year it will be empty, or old dead stems anyway. I’m in 6b, NW Ohio, so I’m very familiar with your zone. I‘m a native landscape designer with a master’s degree in Wildlife Biology, so I obviously strongly recommend native plants. They are much easier to care for once established, and much better for the wildlife and environment. I would recommend an Inkbox Holly, which is a native evergreen with a similar look to boxwood. For another evergreen I would recommend a small juniper (I have a Grey Owl Juniper that I’m in love with that only gets about 20” tall). Then I’d put in some perennials that vary in bloom time so you have color all growing season. I’ll list some recommendations below. My last suggestion would be a Red Osier Dogwood bush. Generally they are probably a little big for that space, however you can trim them back easily to keep it the size you want. It has white spring small flowers, and then pretty white berries in the fall and winter, which contrast beautifully with it’s most striking feature, it’s deep bright red branches that just pop all winter long, especially in a zone that has common snow fall.

perennials:

* creeping or Moss phlox - lie grow mat with many flowers in early spring

* wild geraniums - early spring bloomers that will bloom again if you deadhead them before the seeds ripen

* Coreopsis - many size and color options that have a very long blooming period

* coneflowers - again many size and color options available

* Blue-Eyed Grass or Bluestar - late spring early summer bloom

* Coral Bells - beautiful array of leaf color options, flowers pretty but subtle as well, many are evergreen as well

* small Wild Smooth Hydrangea (Invincibal is the nursery name I believe) - I have a beautiful white one that stays very small (about 15” high) and it’s flowers are just show stoppers (pic below)

* Joe Pye - there is a short small cultivar available, late blooming through November if now early deep freezes

* Aster - same as Joe Pye, late blooms many of them, and there are a few small cultivars available.

Those would give you a variety of colors and something always in bloom. I’d also try to stick in a fern or two if you can. maybe behind other perennials that would somewhat shade it. Many ferns will grow in sun, but they need a lot more water that way. There are a few that are evergreen in our zone, Male Fern, Christmas Fern, and another I cannot remember at this moment.

That is my little hydrangea with 2 of my evergreen Coral Bells to the back right.