Better luck with dahlias

Last year I lost all my dahlias, which I had grown inside. This year I put half of the tubers directly into the ground. The other half were grown inside again, however I followed our CSU garden extension's advice. I mixed potting soil, compost,coconut fiber all together in a metal tray, baked it for about one hour at 215 degrees, added the fertilizer and planted the tubers. They all grew very nicely. The tubers planted directly into the ground did not do as well due to slugs in spite of our dry climate. Yes, I put Escar-Go around them, but I still lost half of them. So, next year I will grow them all again inside using the baking method.
Unfortunately we had about 5 hail storms, and all my plants suffered; still where I live we had no tornadoes.