my bearded dragon's gonna lay eggs soon and I looked all over and I can find vermiculite perlite or hatch right, what could I use other than those?????
A--- sphagnum moss will hold the most moisture in the soil. B---Vermiculite and Perlite have no nutrient value so will not creat any runoff. Pine sawdust unless well composted is bad for your garden.
All the listed soil additives are excellent for improving soil properties. But solely for soil water conservation and reducing nutrient runoff by erosion, the best additive is one that *physically covers* the soil surface like a soil carpet or mulch. That would limit your choice to either pine sawdust or sphagnum moss. Between these two, sphagnum moss has a higher capacity to absorb and retain water than saw dust. So, the answer to both A and B is sphagnum moss.
