Great question @mbillion. The “best” way to represent this, in my opinion, is with a new “Product” asset type. We don’t offer this feature in core farmOS yet, but it is something we have been considering and working towards for a while. The idea is: the planting assets themselves are not the product, but they “transform” into product assets.
We are thinking about this generally, so that the same idea can be applied to any asset type. Imagine a Planting asset that is harvested and packed into various size boxes - you may want to have separate assets to represent each size box, and how many you have of them at any given time (inventory management). Similarly, you may have milking cows that create milk product inventory. Or beef cattle that become meat products. Or maple trees that create sap/syrup products.
Some of this thinking is talked about in this related thread about ecommerce: eCommerce integration
So that’s the plan we have in mind to be able to represent what you describe. 