National Trust director general Fiona Reynolds has been made a Dame for her services to heritage and conservation.
Meanwhile, former vice-president of charity Perennial, Ian Flanagan, has been awarded an OBE for services to horticulture.
Flanagan served as chairman of Perennial from 1998 to 2007. He oversaw the charity's transition from a traditional benevolent society caring primarily for elderly gardeners within residential homes into a modern UK-wide organisation tackling the issues and problems faced by horticulturists of all ages and sectors.
OBEs were also awarded to: former commissioner of English Heritage Michael Cairns; Association of Garden Trusts president Gillian Drummond; Commonwealth War Graves Commission director of information and secretariat David Robert Parker; and Lake District National Park Authority chairman George Thornton.
MBEs went to: head of the Nematode Interactions Unit at Rothamsted Research, Professor Brian Kerry; Central Scotland Forest Trust chief executive Simon Rennie; head groundsman of the All England Lawn Tennis & Croquet Club at Wimbledon Eddie Seaward; National Trust guidebook editor Oliver Garnett; Ann Trevor-Jones for services to the National Garden Scheme; Colin Weightman for services to beekeeping; and manager Nancy McIntyre of Scottish Wildlife Trust's Jupiter Nursery for services to conservation and the environment.
Former horticulturist at Home Park in Windsor, Geoffrey Peers, has been honoured with a Royal Victoria Medal.