I've done U-pick vegetables before, putting this place together as a U-Pick/Pick Your Own vegetable farm.
You can expect the kids to eat some product, that's what kids do. They can eat up some berries if left alone, but it's not a feeding frenzy. A pound of berries or fruit would be a pretty big kid with a hearty appetite. A few ounces per kid is a small investment for a future customer. If the kids have an enjoyable experience, they'll want to come back every year (with their wallet-carrying parents).
Consider hosting school groups immediately after lunchtime. Before they enter the orchard, take a few minutes to talk about safety (
bees, snakes or mosquitos, thorns, climbing and falling, trip hazards) and while you're at it, discuss sanitation and washing of food before consumption. Washing the food is important to clean it of chemicals (EVIL) and bugs. Be sure to place the food washing station near the scale and cash register.
I've had people march through freshly planted lettuce and beans, completely oblivious, stomping on the beds into which I've spent hours prepping. Did I mention my hair loss?
Add stakes and string around the areas that do not require additional stomping. If the string is not enough, make it a few stretches of string. Use twine, rope, mark the area with logs as well. You don't have to go all the way to concertina wire, but a clear demarcation would be a great help. Be sure to mention cow manure. That'll keep them watching where they walk. Kids are small and don't weigh much. Many plants can take a little bit of abuse. Kids can get out of hand, throwing things, running around, tearing up the place. There is a time to bite your tongue and a time to reign them in. Experience on your part will help you determine the difference.
This one little girl asked if she could pick a flower.
"Go right ahead, Darlin' " I replied.
A few moments later she shows me her pretty flower...with all the leaves...and stems...and roots intact. (more hair loss)
I grabbed a cup and some
compost and helped her repot the flower so she could transplant it into her own garden at home. She was overjoyed, her parents were all smiles and spent some money on fresh produce.
Some damage will occur from time to time. Finding a way to minimize that damage to acceptable levels will be needed. A 5 minute talk before entering the growing areas can go a long way to this end.
You've spent money to
advertise to get them to come. Other farms are spending their money to draw them to their farms. They chose your farm as the place to spend their hard earned money. I'd be bending over backwards to see that they are delighted. I want them to come back and tell all their friends what an awesome place it is. Each time they come back gives me another chance to familiarize them a little bit more about a particular plant or vegetable or safety topic. A few trips to the place and they'll have a good idea of what's going on.