With limited space urban gardeners are challenged with optimizing what goes where and which plants work best together. In our garden we call this "layered gardening". We try and arrange plants that work well together based on height, growing characteristics, space needed for each and other factors - and this is always something we learn from yearly. The furthest bed in this photo is an example of one of our beds this past year which supported five different plants.
At the furthest you can see framework supporting cucumbers. Three varieties of mint are planted in front (*yes, we realize that mint will come back year after year without serious work to remove it...we're fine with that!) A couple cayenne pepper plants are planted where the mint is and at the far right a larger oregano plant was planted. Finally the vines you can see spilling from the bed are from a butternut squash plant - planted at the edge of the bed and pulled over so its' growth will be outside and along the bed taking up almost no room inside.
The mint and oregano are low growing plants, the peppers grow higher but max out at 2' - 3' and the cucumbers grow quickly up their trellis to grab sun above all the rest.
SIDE NOTE: the mint, oregano and peppers will grown and produce deep into fall in our region but the cucumbers will die out late summer - at that point we took up the cucumbers and planted pole beans which produced until the first frost in December.