Q.Lots of buds but they are hard and are not developing
Lots of buds but they are hard and are not developing. Have I given them too much fertiliser? I cut the plant down a couple of months ago and it gets lots of healthy leaves and they are covered in buds but not developing.
I'm not sure of the type of plant you are referring to.
Buds that don't open or develop could be a few different issues.
Lack of proper light, watering, pollination or as you mention to much Nitrogen.
Also insects can cause buds to fall off or stop growing.
If you suspect you over fertilized, you can add Phosphorous. Bone Meal is great way to do this.
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/bone-meal-fertilizer.htm