Pour the 2 cups of liquid lawn fertilizer in the 5-gallon bucket. Buy fertilizer in liquid form, or follow the package directions to make it from fertilizer granules.
Stir 4 lbs. of Epsom salt (magnesium sulfate) into the liquid fertilizer with a paint stick, adding a little at a time and stirring gradually to dissolve the salt. Coupled with the fertilizer, the magnesium sulfate gives grass a nutrient boost to help it spring back with lush, green growth.
Pour 1/4 cup of green food coloring into the mix and stir until the color is thoroughly incorporated. Add more or less food coloring to adjust the tint of the mixture.
Pour the mixture into the tank of the hose-end sprayer attachment. This hooks right up to the garden hose so that the dye is able to mix with the water as it is sprayed.
Adjust the spray nozzle to a wide setting and begin spraying the lawn in one corner, sweeping slowly from side to side until the lawn is covered. Let the dye dry and then repeat on areas that are extremely dry or brown so the color is uniform across the lawn.