Existing use for the purposes of horticulture or as a 'garden' to the extent that it is limited to the cultivation, planting or growing of grass, trees, seeds, vegetables, fruit, plants, shrubs, bushes or flowers; and the tending to and enjoyment of such land by persons who have a private right to access and enter the land ('enjoyment' in these respects including sitting, walking, roaming, running and play that does not involve the use of installed or fixed apparatus or equipment')