So I got a spot dead center of 2 other gardeners in our building rooftop garden. I'm second from the left, the zone with all the perrenials from last year the someone forgot to clear.
The problem I'm having is that I plan on filling my alloted area with soil to the brim. Sadly the building doesn't buy us soil so it's left up to the individual.
I don't have a way to shore up the sides as the beds don't have dividers. And the neighbor has already planted, so shoring might disturb the border and potentially destroy some things there.
Naturally, when I fill it up it'll form a hill and create runoff and maybe even erode and start filling/drowning the neighbors (namely the one on the right) border regions in soil.
My question is, what is a good way to keep the "hill" but make it staggered and resistant to running off. My ideas were to create small mounds and plant on them.
Will making mounds that are sort of going from the "peak" down to the lower regions be good? This loosely comes to mind 
Speaking of mounds, can vegetables even grow well in them? I'm talking 3 or 4 inch tall rotund mounds with motes around them. The motes would also form a link with the other mounds and (hopefully) channel the runoff to someplace that's not directly onto the rightmost neighbors seedlings.
Any suggestions or help is appreciated, especially out-there solutions!
