Question
I'd like to put mowing strips around some trees.  But almost all of the pavers I find are rectangular.  So there would be pie-shaped gaps between the pavers where grass could easily grow.  Cutting pavers so that they were pie shaped would work but would be expensive and would have to be done very carefully.  I've seen crescent shaped pavers but I can find them in only one size, 36" dia., which is much too large.  Do you know of manufactures of crescent shaped pavers?  My web searches for crescent pavers indicates that they are not at all common.  Thanks,  Bob

Answer
First "pavers" are what you walk on, I believe you are meaning "edgers." I am not nor will I ever be a proponent of any modular edging. It is just not what we use in high quality landscaping. We generally use steel edging or just a simple well maintained trench. However, if you want an edger there are some scalloped concrete edgers with grooved joints. Most large home stores and nurseries carry them. As for small tight circles, no one manufactures anything that small that I am aware of. Try making a 3' by 3' square using the rectangular straight segments.
However, if you really want a nice look use bricks. Dig a 6" deep trench about 6" wide, fill it with concrete and set the bricks in the wet concrete so they are set down in it about 1 to 2", repeat all the way around. If you like, mortar the joints to ensure no gaps. Like in this picture-  http://img4.southernliving.com/i/2007/02/savannah-garden/brick-border-m.jpg

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Best of Luck
Sean J Murphy
www.amenityarchitects.com