Barb, I think 1/4 tsp in a gallon is a bit weak. That would be one-twelfth strength. I'd use at least 3/4 tsp in a gallon. I don't think you should use it as a foliar spray on seedlings, just use it for watering. Seems to me they don't recommend using it as a foliar on houseplants, so I'd think that would apply to seedlings as well.