Depends on what you are shipping and to where. Most roots are trimmed not to a diameter but to a length of root. Most are trimmed so that the roots are about 6-8 inches long and will fit in a bag. You should remove all of the hair roots before sending.

Do not send with any dirt on the roots because of various problems that reside in the soil such as Sudden Death oak problems.

thanks for the info. I will be sending from Vt. to MN. I washed off all the dirt and I will trim off the hair roots. I also soaked in insecticidal soap and nuked with bug spray. I don't think Minnesotans would like any of our bugs.