She has delivered lectures on herbs and was also a qualified physiotherapist.
Roberts operated the Margaret Roberts Herbal Centre in Magaliesburg. Here, she propagated the ideologies of natural living.
The centre boasts herb gardens, a nursery, apothecary, potager garden, chapel, lecture hall and even a fairy gallery.
Franchi Seeds' Andrew Collings had met her in South Africa and said she was an "inspirational horticulturalist".