I host a modded server. It became apparent after a couple of months that no crops were growing. I uninstalled all farming related mods one by one until GMH was the only farming mod left and issue persisted. After removing GMH the problem disappeared. It is possible that it conflicts with another mod but in my opinion the bug originates in GMH.

Current server modlist immediately after removing GMH:
Mod Options
Common Sense
Simple Overhaul: Blades and Spears
Hand Crank Flashlight
Rename Containers
Maintenance Repair
Rideable Truck Beds
Faction Map
Donazo's Fine Fisticuffs
Calorie Fix
Defenestration
The Workshop
Spongie's Hair
Descriptive Traits
Carts and Trolleys
Tsarlib - dependency for carts
Snow is Water
Become Desensitized
Filibuster Rhymes Used Cars
Expiration date
Dynamic Traits
More Simple Traits (Dynamic)
Spear Trap
Driving trait
Build wells
4-Color bic pen
Fanny Packs
Recycling
Muldraugh FD
Padded Armor
Brita's Weapon Pack
Brita's Armor Pack
Garbage Truck
RV Interiors
Halo M12 Warthog
'83 AM General M923
'67 Cadillac Gage Commando