Houseplants, green roofs, lily beetle Gardening with the RHS

This week we're talking green roofs with designer Ula Maria (past winner of the RHS Young Designer of the Year competition). We have part two of our chat about houseplants with biophilic designers and Virtual Chelsea exhibitors Studio Roco; plus the Gardening Advice team answer members' queries on dealing with lily beetle, groundcover shade planting and growing olives.