Okay, about garden plants & Seasons...
I've discovered that when a fruit, vegetable or flower goes out-of-season (dormant), I can move the non-producing item into the house's inventory and replant with an in-season item from my inventory.
When dealing with plants other than trees (because a single tree takes up an entire planter box), it's easier moving the planter box with its collection of 4 plants into inventory than removing each plant individually. The planter box and the plants will be automatically separated into like-item stacks in the house inventory (all the bluebells will be stacked with the bluebells, the onion plants will be stacked with the onion plants, and all the planter boxes with the planter boxes), so you can place a freshly emptied planter box out of a stack of planter boxes from inventory and fill it with in-season plants. Also, because your household inventory is kept in a last-in last-out fashion when cycling through the seasons, your plants will be kept in an odd kind of default order.
As you cultivate your plants the quality of the fruit / flower increases from "normal" -> "nice" -> "excellent" -> "magnificent". As a plant is kept in inventory, it does not appear to suffer any ill side effects and retains its quality. Though there may be an advantage to keeping them in the ground if the plant can evolve while dormant (I can't remember if they do).
Fruits & vegetables harvested from your plants can be stored in a refrigerator's inventory. Flower inventories are stored in the flower arrangement station. As a particular plant comes into season, it may be advantageous to sell off the old stacks of fruits, vegetables & flowers of lesser quality from your inventories.
High quality fruits, vegetables & flowers can be removed from the refrigerator / flower station and be planted like seeds, but you will have the advantage of increased quality of plant and will not have to cultivate "from scratch." So if you want to grow a whole vineyard of magnificent grapes, it is to your advantage to cultivate a single planter of grapes and sell off your harvests until their quality reaches "magnificent." Once your plant is producing magnificent fruit, use the harvested magnificent fruit to seed the rest of your orchard. It's a whole lot easier this way than "evolving" an entire orchard one tree at a time until they're all magnificent.
Oh, and don't ever worry about loosing your refrigerator inventory when you sell your refrigerator. My character donated his refrigerator to charity with one accidental click... The inventory did not get sold away with the old refrigerator. I bought a new refrigerator, and my old inventory was still there.
Okay... So, I'm at a point where I want to move my house. I have: 1) a house inventory, 2) a refrigerator inventory, 3) a flower station inventory, and 4) an individual inventory for each of the 4 characters living in the house. In live mode, I can move inventories between the refrigerator/flower station and any individual. There are some items I can move in live mode, like the painting easel or small placement objects, that I can move into an individual's inventory.
What about those items that don't seem to budge in live mode, that can only be moved in build mode? These are the items most likely to be retained in the house inventory. When I vacate the house I imagine I will have to move as much junk into the characters' individual inventories and everything else will have to move into the house inventory.
I am hoping the house inventory moves with me, but everything that I leave placed in the house will be forfeit.