If you want container plantings that hold up year round without any fuss, go for this green-on-green medley of sturdy, easy care plants. This trio even tolerates quite a bit of shade. The textural interest lasts all year, even though the Japanese forest grass (Hakonechloa macra 'All Gold') dies down for a few months in winter. Although as you can see in these photos taken today, the grass is still going strong in mid-November.
What makes three green plants look so good? It's all in the interplay of texture; the mahonia is tall & rigid, with sharply toothed leaves. Then in winter, when the forest grass dies down, the mahonia stars with a burst of fragrant yellow flowers (in bud in the photos) that attract our native hummingbirds. It's quite a site to see a shimmery little hummer sipping nectar from that yellow topknot of flowers on a frosty morning.
The autumn fern (Dryopteris erythrosora) is evergreen, with a crisp texture to its splayed leaves. Just cut away the old foliage in March or April and watch the new coppery leaves unfurl. The Japanese forest grass flows over the side of the pot, shiny and nearly liquid in its sheen and shape. The bottom photo gives you a close up look at the textural contrast. I can't imagine any combination of plants that looks as good for so long, with such little care.....you could always tuck some bulbs in the pot for spring bloom and annuals for summer color, but you don't need too - these three stalwarts can carry the scene just fine on their own.