How about a new house dedicated to planting? It makes as much sense as giving PvPers a house with a combat ring, or crafters a house to craft, etc.
I could see a WC house, with a manorhouse for living, and 'fields'...pre-made furrows that were ready for planting for about a dozen plants, plus plenty of room for additional planting as needed. It would have a scarecrow, etc, and a larger outside limit (prehaps dedicated to plants).
Now I do realize the database required for just one plant...ages, time in ages, likes met, dislikes interacting, etc.
Heck, if KI really liked us, it could even have a (power) reduction for planting in this housing unit.