I didn’t have time to read all the comments, but just want to say a couple of things. You are living my dream in the country ( especially the part about raising chickens :). My 3 are teens now and we have been limited for several years in the amount of activities we participate in. They have learned to be friends with each other. We have been in a homeschool co-op for the last 3 years and I’m pleased because we found a really good group of families in this co-op. My kids also participate in the local 4H. Living in town we don’t do the animal aspects of 4H, but they have learned so much doing this. Over the years they have participated in horseback riding club, skeet/trap shooting club, sewing club, archery club, robotics club, and entered various competitions through 4H. Overall it has been a good experience for them. I know that sounds like a lot, but the activities are only once a month and they don’t each do all of those things every month. One likes robotics, one likes sewing, two like horse club, etc.
I would suggest asking other homeschoolers in your area if they would like to meet at a park for a couple of hours to play and picnic. Sometimes others are just waiting for someone to ask. I think the key thing to remember is that when looking for social activities you need to keep in mind the character of the people you allow your children to interact with. I’ve had situations where I could see the negative influences someone had on one of my children and had to limit interaction with that person for the benefit of my child. That said, the public school offerings may not be the best situation for your children depending on the situation there.
The best thing I’ve done to find the right balance and the right activities is to pray about it :). And my teens are able to socialize with lots of ages of people, from little children to the elderly, because they have always been around various ages of people. They all like bing with the younger kids at co-op and can converse with them as we’ll as with the parents of these children.