When buying mulch, consider paying the few extra dollars per yard for the higher quality "bark mulch" instead of the impostor "wood mulch."
Bark Mulch is better for plant health. It contains waxes that shed water and increases the water capacity in the soil. Bark also increases phosphorus and potassium levels in the soil; macronutrients that are important for plant survival. Bark maintains its color longer. A small amount of environmentally safe "food coloring" dye may be added to increase color consistency in some bark mulches, and that is ok. But it is the higher bark content that adds to color longevity. One can buy mulch that is 100 percent bark. The more bark, the higher the price. But the benefits outweigh the cost.
Wood mulch may look good when purchasing it, but buyer beware. Wood mulches have a high carbon – nitrogen ratio. This means that wood mulches rob soil of nitrogen, a primary nutrient for plant growth and survival. Some companies making wood mulches are grinding up pallets and building material, stumps, or unwanted tree limbs. They rely on dye for color, but after the wood mulch is spread out in a yard, its color quickly fades to gray or pink when washed out by rain or dried out by the sun.
So be careful when buying mulch, because not all mulch is the same.