I have 2 – 3 year old stable manure. Can I use that just like bagged compost from the shop for seeding, pot-planting etc. or is it too strong/good/…?
Well-rotted horse manure can be used for potting, mixed 1:3 with ordinary soil as it tends to be quite rich.
It would be too rich for seed sowing and likely to cause seedlings to be too soft.