Quarterman joins the charity from the Anaphylaxis Campaign where she was corporate partnerships manager.
She said: "I am delighted to be joining Plant Heritage at such an exciting time, when our work of plant conservation through cultivation is expanding. Our National Plant Collections scheme is second to none and we are looking to propagate best practice in plant conservation within and beyond the UK.
"Through proactive identification of garden plants at threat of extinction in the Threatened Plants Project, and members' conservation through participation in the Plant Guardians scheme; we aim to make Plant Heritage a charity with a distinctive place in the conservation arena, appealing across all ages and with a growing number of supporters."
Plant conservation charity Plant Heritage formed in 1978. Its National Plant Collection Scheme includes 630 plant collections in the UK and Ireland.