I would go for a very lush jungle vibe. Where are you? In NYC? Philly? Zone and city really helps. How much sun do you get? I'm guessing not much.

Elephant ears are big, bold, do well with little sun and are cheap, I'd get 2 or three of them. You can get them in Black, and there are some with dramatic colors, like Waikiki (which is often not that cheap). You'd need to dig them up for the winter (assuming you are in the northeast) but if you got plain green ones, you could just toss them and replant the next year. I do know one that came up in the Boston area after wintering over, but I wouldn't expect that to happen on a regular basis.

Something like this design could work for you, I'd do coleus and impatiens for the two rows of plants. You can do it dramatic with black elephant ears, hot pink impatiens and dramatic coleus or a calmer design with colors of your choice green and white, say. This is an annual garden, but it's quite affordable for the size and plenty of plants don't winter over well in small planter boxes.

seasonal color · More Info

The drama (this picture is for the black elephant ears, but you could add the Japanese forest grass, too, it's a perennial and should do well in shade)

Summer Color with Perennials · More Info

My guess is this is New Guinea Impatiens, but I could be wrong. You can certainly get some impatiens that looks pretty similar, even if this isn't impatiens

Gardens, Perennials, Shrubs & Trees · More Info

Coleus comes in all sorts of colors from this red to purples and limes.

Flower Containers · More Info

This gives you a sense of the options, so they would work well in a green and yellow scheme.

These potted coleus love the ocean breezes · More Info

Would bamboo (clumping varieties) survive where you are? I love its height and its soft featheriness.

Some good ideas above. If it were me, I’d want to break up the long and narrow ‘bowling lane’ feel of the space (which feels accentuated by your tile/fencing). Could the table be turned 90 degrees- even if you needed to butt one of the sides up against the fence? This might allow for another zoned seating area with more comfortable lounge chairs in the back.

Everything currently feels so dramatically stark— it definitely needs softening through furnishings and plantings (including interspersing some containers throughout). And the plantings in the back should definitely bring some height— small ornamental trees in the corners or bamboo as previously suggested, etc.

If you let us know which city/state you’re in— and if you are expecting the container plants to overwinter in place (which will dramatically decrease your options), you will get more helpful suggestions.

Maybe a rug could break up some of the linear checkerboard floor? (It would cover one of the two drains, though. Would enough water drain through it?)

Is this a photograph of your courtyard or an AI mock up? The table and chairs seem out of scale with the barbecue.