I used to run a nursery that only sold edible plants, so I really appreciated the exemption. I didn't want to bother with calculating, collecting, and reporting sales tax. We were all volunteers and there was enough work to do already. I have not previously heard about an exemption for direct sales of agricultural products, which might have been nice too. We operated under the food exemption. Florida considers seeds and plants that produce food to be food and they are not subject to the requirement to collect and report sales tax, though I believe you can do it anyway if you want to for bookkeeping simplicity. I could be wrong about that last part. Anyway, you don't pay tax on food from the grocery store and shouldn't have to pay tax on fruit trees from the hardware store.
There was once we wanted to distribute some nitrogen-fixing legume trees to go along with our edible plants for chop-and-drop fertilizing, but there's no exemption for fertilizer for food. If I had known about the direct sales of ag products, I may have looked into that, but all the other farmers I talked to who sell some ornamentals told me they collect tax on them, so idk. Anyway, I came up with schemes like "buy five food plants and get a fertilizer tree for free" so I wouldn't have to do the tax paperwork. We never did get a tax ID.