Powdery mildew is a common fungal disease that affects a wide variety of plants. True to its name, the fungus is easily identified by the light grey or white powdery spots found on infected leaves. It can also be found underneath the leaves or on stems, flowers, fruit, or vegetables. Powdery Mildew spreads and can rapidly cover most of the leaves on the plant. Young plants and seedlings are especially susceptible. Although rarely fatal, if this disease is left unchecked, it can cause serious harm to your plants by depriving them of water and nutrients. Most infections cause minor damage, such as leaves turning yellow or becoming withered or distorted, but plants can also become weak, grow slower, or stunt their growth altogether.