The answer to 'why is my shrub pests' is that your shrub may be infested with common pests like aphids, spider mites, or scale insects. These pests can feed on the leaves and stems, causing damage and discoloration to the plant. Symptoms may include stunted growth, wilting, and loss of leaves.
To address the pest problem, you'll first need to identify the specific pest affecting your shrub. This can be done by closely inspecting the plant and looking for signs of the pest, such as small insects, webbing, or sticky residue. Once you've identified the pest, you can choose an appropriate treatment method, such as using insecticidal soap, neem oil, or introducing beneficial insects like ladybugs. If the infestation is severe or persistent, it's best to consult with a professional landscaper or pest control specialist for more advanced treatment options.