Need design help for table runner
 

My mother in law wants a peach and green table runner. I have put this together without using a pattern. It seems a little short as each half measures 18 inches.
She always uses a centerpiece in the middle and I was thinking about putting some kind of quilt block in the middle to make it longer. It will be covered anyway. I will also probable do a small border.
Any suggestions?

It looks great. Whatever you put in the middle, it will enhance it. She is going to love it. What kind of block are you thinking of?

I don't know what kind of block. It would be really hard to add to the middle by continuing the pattern because the pattern is build with strips from the center to the sides not center to end. I still have more strips but they would only follow the pattern to make it wider.

I'm not sure about a different block in the middle. I think I would try and piece a strata like Tartan suggested. Or maybe make a small section of the pattern going perpendicular to the current one and mirror it????

What if I turn them sideways and make more to add to the length

Turning it sideways loses some of the coolness of the bargello effect. If you're willing to do the extra work, I'd add some more Bargello rows (columns, actually) on both ends 'til you get the desired length.

The strata is built to go from the center to the sides. I already have it sewn. I don't know if I have enough fabric left to build a strata of the sizes that extend from the center to the ends.

take a piece of solid and lay the bargello at the sides of it.... how does it look with a solid center?

Have you thought of adding a piece of the green in the center and quilting it SITD taking the lines across the solid to the other block ? If still not long enough you could add strips of other color (or green) at each end. Just a thought or two.