This is a plugin for Minecraft Bukkit/Spigot/etc servers that allows you to easily replant seeds and create fully automatic farms. Any dropped seeds (including those dropped by blocks, entities, or players) will be replanted after a certain (configurable) amount of time if there is a farmland block nearby (range also configurable).
Currently, the plugin auto replants Wheat Seeds, Pumpkin Seeds, Beetroot Seeds, Melon Seeds, Carrot, Cocoa Beans, and Potato.