The BBC and HTA are looking for garden centres to help with a world record bid.
The "fantastic footfall driving opportunity" will be shown on BBC2's Autumnwatch and involves two world record breaking attempts. They are the largest number of trees planted in one location in one hour and the largest number of trees planted in multiple locations in one hour.
The BBC has chosen the HTA for its Tree O'Clock project to help find garden retailers through which to distribute trees.
The BBC will provide the trees free of charge. Contact email@example.com or call the HTA on.
Tree O'Clock takes place at 11am on 5 December.
For more information visit www.bbc.co.uk/treeoclock.