Flowering plants typically thrive in bright sunlight, but the mulch spread around them does not. From the moment you put wood-chip mulch in a plant bed, it starts to fade, eventually looking dull and unappealing. Replacing wood chips, or bark mulch, is expensive, but you have another option to brighten the area. Using a mulch dye gives mulch a strong, lasting color without the hefty price tag of buying new mulch.
Choose a day to color wood chips when the wind is calm. Doing so will help you direct the mulch dye spray onto the wood chips, not onto you. Put on personal protective clothing and gear, including a long-sleeved shirt, long pants, gloves, safety goggles and a dust mask. Although most mulch dyes are non-toxic, avoiding ending up with an eyeful of dye while you're mixing or spraying it is wise.
Pour water into a garden sprayer, add the mulch dye and mix the ingredients by shaking or stirring the solution with a paint stirrer. Follow your mulch dye manufacturer's label or package directions for the proper amounts of water and dye to mix. For example, one manufacturer advises mixing 4 to 6 ounces of its dye with 1 1/2 gallons of water, but amounts vary among manufacturers.
Point the garden sprayer's nozzle at the wood-chip mulch that is at one end of a plant bed. Hold the nozzle at least 12 inches off the ground, lifting it higher for a wider spray area. Pull the garden sprayer's trigger or push its dispenser button to begin spraying the water-dye mixture. Move the nozzle back and forth to color all the wood-mulch. Walk backward, continuing to wave the nozzle over the mulch.
Wait six hours for the dyed wood chips to dry completely. Rake the wood chips with a steel-tined garden rake, if desired, exposing areas not touched by the dye. Repeat the application process by mixing more mulch dye with water and spraying the mixture on the portions of wood chips that weren't dyed.