Graham Wellfare, Ranger with the National Trust at Saddlescombe farm is leading a walk in June to see these beauties, preceded by an illustrated talk in the learning centre. Places are limited and the cost is £10.00. Booking is essential. A few places remain: details at http://www.nationaltrust.
For an idea of what you may see on the Downs at this time please see https://sussexrambler.blogspot.co.uk/2012/06/fragrant-orchids-in-sussex-today.html
And if you type "orchids" in the search box you will find forty more entries on native orchids.