they should give it a little boost for a very long time... dont know exactly how long tho... good luck...
Abattoir Dream Reviewed by Abattoir Dream on . Worm Castings last how long.....??? Worm Castings Last how long ?? .....in your soil mixture, soilless build, standing along with perlite and vermiculite or used in a tea..... Just how long will worm castings last....meaning feed the much needed and used "N". What I use in a soil build of Foxfarm Ocean Forest Soil mix, Botanicare Ready Grow (moisture formula), Worm castings, Blood and Bone meals, Mexican and Jamaican Bat Guanos, Greensand plus, Sea Kelp (Ascophyllum Nodosum), Dolomite Lime, perlite and Rating: 5