Im gonna plant some autos outdoor in a few days. I bought some soil that contains humus compost. I also have some horse manure on garden and garden soil. Should I also add horse manure to the soil or only the soil with humus compost? If I should add both can u please give me a ratio of : Bought soil with humus compost, horse manure, garden soil?
Kind of an impossible question to answer due to so many variables. No one can really advise you on ratios because no one knows the real nutrient content of any of the base products. Best thing I could say is just make sure you have good aeration. You can always top dress but you can never remove.
be very cautious as the humus thats most of the time wet to damp, will hold that horse poop nute even making it toxic later, as the water is used or vaped out ...IMO