Methods of improving the growth of a plant by applying a plant growth effective amount of a plant growth composition that includes a hydrated aluminum-magnesium silicate and at least one dispersant selected from the group consisting of a sucrose ester, a lignosulfonate, an alkylpolyglycoside, a naphthalenesulfonic acid formaldehyde condensate and a phosphate ester to plant propagation material in the absence of insect pest pressure.