Katolen has been accepting student apprentices already attending structured herbal medicine education since 2002. Since 2012 Katolen Yardleys clinic has been approved as an official Dominion Herbal College Student Training Clinic, where students of herbal medicine programs have the opportunity to obtain clinical training hours under the supervision of a qualified Medical Herbalist. In addition, she has mentored students who are self learning, from Heartwood Herbal Medicine (UK) and the Wild Rose College.

Apprenticeship training assists in preparing students to become herbalists at the professional level through observation and hands-on practice in a clinic setting and/or online. Days in the herbal mentorship student training clinic vary depending upon the weekly tasks required- some days will be busy with the running of the herbal business and office tasks, other days will be directed towards self research, hands on experience, dispensary and medicine making and of course time for case history taking while interviewing clients in a clinic environment. Students will build competence in performing examination techniques while learning consultation skills and clinic assessments.

For professional membership in various Herbal Medicine organizations such as the National Institute of Medical Herbalists, American Herbalists Guild and CHA of BC and Ontario Herbalists Association; clinical experience is an essential component of the professional training. Most governing bodies require 400-500 hours of supervised clinical practice to qualify for the designation of professional Registered Herbal Therapist.