Most of the trees will go in this winter, with Frost Landscape Construction working with Hillier Nurseries on supplying and planting new trees and moving existing trees seen during the games. A temporary nursery has been built to store 250 trees for relocation, with roots covered in straw bales.
"Around 4,300 semi-mature trees, with girths of 14cm or more, will be planted during transformation," said a spokeswoman.
"Around 3,300 will go in the North Park including 51 black poplars and around 1,000 in the South Park."
Meanwhile 127,000 shrubs will be planted and around one million herbaceous plants added to the park, approximately 720,000 in the North Park and 300,000 in the South of the Park. Almost one million bulbs will be planted and 36,000m² of new turf laid.
Right now teams from Frost Landscape Construction, Willerby Landscape and the Landscape Group, which will also look after the finished park, are replacing hard surfacing with earth and sculpting soil in the north. Temporary structures such as seating are being removed.
Other suppliers include Tamar Nurseries, British Flora, Crowders Nurseries, Wildflower Turf and Lindum Turf. Ocmis is handling irrigation in North Park, with Waterwise in the south. Apes at Play is supplying Scots pine play structures and Fountain Workshop water features.
She said: "We will also continue to bring in the expertise of the Sheffield University wildlife meadow consultants. The south plaza is being designed by James Corner Field Operations, with 5m-ribbon of planting designed by Piet Oudolf."