The Sims 2 Seasons Gardening Club?

Just call service and click on gardening club and a lady will come over. Depending on their initial assessment of your garden or if you haven't yet joined.

If the gardening club sim left your lot and they never told you that you were a member, then you are not a member. After they check iver your gardem, fruit trees, and yard if everything is good enough for them they will tell you that you are a member of the garden club. If they did not, make some improvements to your garden and invite them again. Feel free to work on your garden while they are there to make sure every plant and tree is at least healthy, preferably most are thriving. Make sure there are not leaves laying everywhere if it is Fall, it you pets and an animal has dug a hole in your yard make sure you fill it in. Add some decorations to your garden like lights.

Hope that helps.

probably call them im not sure because i dont have it yet..but you should let you call and invite over then join