There have been years in Finland when container seedlings of Norway spruce (Picea abies (L. ) Karsten) planted in the summer have been damaged by early-autumn frosts. For August and September plantings. the seedlings can be hardened by means of short-day (SD) treatment. https://www.getpureroutine.com/hot-sale-ethical-nutrients-mega-magnesium-powder-citrus-450g-for-sale-save-big/