Beginner Gardening: Good Growing Practices - an Overview for Beginners, 1 by tapla

tapla wrote:
Your seed flats want a very open (porous)/well-aerated soil, not something as water-retentive as Turface fines. Roots LOVE lots of air surrounding them. I would be thinking something like the 5:1:1 mix for seeds.

MG soils are already very water retentive and contain a very high % of sphagnum peat, so there really is nothing to be gained by adding more peat; in fact, it's more likely to be counterproductive than a benefit.

Whenever you add anything to your soil that is intended to supply singular nutrients, like in the case of Epsom salts where Mg is the target nutrient, it's more likely to be a negative than a positive. Epsom salts (MgSO4) supply magnesium (Mg) and sulfur (S). Sulfur is only very rarely deficient in soils, which leaves us with the assumption that any benefit derived from Epsom salts would come in the form of its Mg content. The question that needs to be asked before you use Epsom salts is, "What leads me to think I have a Mg deficiency?" If you don't have an answer or a reason to apply something, especially when it's an element or compound targeted at increasing the amount of a singular nutrient, you're better to forgo the application; because if it's (magnesium) not deficient, more can't possibly help; rather, it will be a limiting factor.

Al