I have four full farms, each one is 24x24. Except for F1, they are all plowed and planted. 3,072 for the last three farms, and around 700 for f1.
I prefer to harvest/plow solo, I don't care if it's flowers, trees or crops. I even like doing flowers and trees, since i'm doing it now for the money, vs the experience. I've got over a million experience, and now over 11 million. I started Saturday with, over 57 million, and spent down to 7 million buying F4. If I don't like the people I'm harvesting or plowing with, i'll simply leave the farm.
I do ask people if I notice there trees or flowers are ready, if they want them done, but don't insist on it. I'm very particular about both, and don't often hire people to do them. I have probably over 600 trees now, and close to 9,500 flowers. I havent' counted all of either one lately. All of my trees of the same type, come due at the same time. I don't add trees, of a particular type, until those are ready to be harvested. I have for instance 101 coconut trees, and people tend to miss anywhere from 5-10 trees when harvesting them. Well, when you have 600 trees or so, of varying types you end up harvesting 30 or so yourself, it's annoying. At least IMHO.