Having attended recently a large and elaborate outdoor birthday party for a small child, I thought it might be fun to read from an old etiquette book about the proper way to entertain outdoors.
This is from Manners and Social Usages, by Mrs. John Sherwood, published in, well, the book has no date on it, but I would guess the early 1880s. The section begins with ways to ensure good weather, and to deal with bad and then proceeds to deal with amusements and food.
"A hostess should see that her lawn-tennis ground is in order, the croquet laid out, and the archery tools all in place, so that her guests may amuse themselves with these different games. Sometimes balls and races are added to these amusements, and often a platform is laid for dancing, if the turf be not sufficiently dry. A band of musicians is essential to a very elegant and successful garden-party, and a varied selection of music, grave and gay, should be rendered. Although at a dinner-party there is reason to fear that an orchestra may be a nuisance, at a garden-party the open air and space are sufficient guarantees against this danger."If the hostess wishes her entertainment to be served out-of-doors, of course all the dishes must be cold. Salads, cold birds, and ham, tongue, and pate de foie gras, cold pates, and salmon dressed with a green sauce, jellies, Charlottes, ices, cakes, punch, and champagne are the proper things to offer. A cup of hot tea should be always ready in the house for those who desire it."Ladies always wear bonnets at a garden-party, and the sensible fashion of short dresses has hitherto prevailed; but it is rumored that a recent edict of the Princess of Wales against short dresses at her garden parties will find followers on this side of the water, notably at Newport, which out-Herods Herod in its respect to English fashions."
Strange that there's no mention of barbecue grills, Jello salads, or Wiffle ball. These must appear in a later edition.