Your photo appears on a website Terry Gardens - a visit to Christopher Lloyd's Great Dixter Wall Garden; the author describes the plant only as Chrysanthemum-flowered Marigold:
http://terrygardens.com/tag/ab...
If you need an exact answer perhaps you could send a message to Great Dixter House & Gardens. Page with contact information:
http://www.greatdixter.co.uk/c...
Their catalog lists the orange color variety of Tagetes:
www.greatdixter.co.uk/nursery-catalogue/products/tagetes-cinnabar/
Here is the 'Cinnabar' variety in our All Things Plants database:
