This may sound weird, but our venue is not very stiletto-friendly. It is actually at my parents' home where I grew up which also happens to be a little macadamia nut farm in Hawaii. We will have a big tent and tables and chairs, but getting around will require walking in grass and also on stairs that my dad built by hand out of lava rock (i.e. they are not very even). We are including with our invitations an enclosure card, and one of the things we would like to convey is that spiky heels are not recommended. This is the wording that we were thinking of using: "footwear suitable for traversing grass, rocks, and macadamia nuts recommended." My only concern is that people will freak out and think that we are going hiking or something, and that this might scare them off or cause them to dress more casually than is appropriate for the event. Is there a better way to convey this message?