Breddy said: "In challenging circumstances, Mark has focussed relentlessly on ensuring an exciting future for the Solus brands. He was instrumental in ensuring that the acquisition by Scotts succeeded, and has helped accelerate the integration of the two businesses. With this mission accomplished, it is natural he leaves to pursue new opportunities.
He added: "May has shown the utmost professionalism and dedication in leading the transition of the Solus team to Scotts. She has now secured an exciting new sales and marketing role outside of the gardening industry."
"In a short space of time, Mark and May have contributed enormously to the future success of the combined businesses. Both will leave with our thanks and very best wishes."
Scotts bought Solus in July.