Perhaps you let them get too big. Over about 18" and they can get quite fibrous. I pick mine between 12-18" and they are very tender.

TomNJ

Mine seemed that way also probably to big The food processor would not touch them My blender did the job just had to put a little oil in and keep scraping the sides to the bottom

Oh and the pesto is very good on crackers

Thank you, yes I did let them get longer than that before I got to it. After that happened I cut all of them to send the energy to the bulbs. I'll have to try it again next year :-)

Andrea