I'm not sure what you mean?

If you mean between the rows then nothing!

I grow my potatoes in short rows across the beds so that when I harvest say my earlies, this releases ground for sowing/ planting quick maturing crops.

Can you clarify what you mean by "besides"

As Teeg. says we need a little clarity please there us a huge number of vegetables you can grown - depends on where you are wanting to grow them.