I don't know if this is of any help to you, but I wanted to create a community garden where I could go and get fruit and veggies and not have to take care of them, and a nice place to meet other sims, relax by a pond.
In RV I created a couple who had all of the necessary gardening traits. I took a residential lot and built a one room, effeciency type house. Put all of the nice things in it so they would be happy.
Used buydebug to get all of the plants I wanted and planted two of each type I wanted in rows. I put a fence around it, put in my sprinklers and did NOT put in a gate. I put in a gate only when they needed to work in the garden.
I wasn't building for a pefect veggie and fruit garden, but a nice community garden to meet others, chill out. So, I was happy to have plants reach great level, some did go to outstanding, excellent levels.
When it was finished, I got rid of the extra plants, two of some and just one of others and placed them about the garden, fixed it up how I wanted (pond, swings, bar and such), turned house into restrooms, put up a fence and locked the gate to pets (the horses and deer will eat your plants if they can get in).
Moved my couple to a nice home, they deserved it after all the work, and turned it into a community lot.
I did find this out, I left some of the plants in a growing state and they finished growing. I wasn't sure if they had to be at maturity before it became a community garden, they didn't.
Once it was a community garden, I lost control over it. I could go and harvest, could go into Edit Town to do some changes, but not much (added in some insects). I don't think I was able to do anything with the garden, I coud move around tables, but didn't try with any plants.