Surely folks on HN understand that, if it was economically feasible to compete on this, then locally sourced flower start-ups would've already become a thing?
Yes shipping and storage seem wasteful, but there are economies of scale involved when centralizing production to areas with the right climate, with desirable soil qualities, with expertise in planting such flowers, etc.
To help local flower growers win out, we would need to increase the cost of shipping/storage/etc. (maybe because we think they are not properly pricing in externalities?). Then we're back in the realm of tariffs and protectionism, which is its own can of worms; personally, I think we can complicate our understanding of free trade, and reasonably choose to impose artificial costs/penalties when it comes to climate protection or environmental goals (as opposed to, propping up certain industries just because they're better at lobbying).
Consider that, it is cheaper/more-efficient for fisherman/crabmen in Alaska or the PNW to send their catch to China for processing (filleting, canning, etc.), before shipping it back to the US for retail. I always found that to be fascinating, that supply chains are such that, it's more economical to outsource the processing of seafood, than for the fisherman to dump their catch to a local processing facility that then sends it out for retail.