Setting up some custom items you can buy I found that saplings, when listed in the SaplingAdditionalData field, don't show up properly in the shop but as recipes for the sapling. Saplings set to the base SaplingPurchaseFrom do.
I didn't look into what all is going on, but I saw that JsonAssets.Mod.RegisterFruitTree, line 500 and line 511 have calls to different versions of new StardewValley.Object(). When I changed the latter to the former the sapling showed up as expected.
Setting up some custom items you can buy I found that saplings, when listed in the SaplingAdditionalData field, don't show up properly in the shop but as recipes for the sapling. Saplings set to the base SaplingPurchaseFrom do.
I didn't look into what all is going on, but I saw that JsonAssets.Mod.RegisterFruitTree, line 500 and line 511 have calls to different versions of new StardewValley.Object(). When I changed the latter to the former the sapling showed up as expected.