Grown like bush beans. Also called "haricots verts", filet beans are very slender and stringless. Their gourmet appearance makes them a favorite of chefs.
Harvest when very slender, 1/8- 1/4" diameter. A continuous yield of "extra fine" grade is maintained by picking every 36-48 hours. Three days in warm weather or five days in cool weather is the maximum interval to avoid oversized, tough beans.