Name one method for controlling insect pests in ornamental landscapes.

Insecticidal soaps and horticultural oils are effective methods for controlling insect pests in ornamental landscapes because they target soft-bodied insects such as aphids, spider mites, and whiteflies. These products work by suffocating the pests or disrupting their cell membranes, which leads to their demise. Insecticidal soaps are comprised of natural plant oils and fats, making them relatively safe for beneficial insects when applied correctly and at the right times. Horticultural oils serve a similar purpose, coating pests to hinder their breathing and feeding.

Other options do not provide effective pest control. Synthetic herbicides are designed to kill weeds, not insects, while planting only annual flowers does not inherently prevent pest problems and may even attract certain species. Applying chemical fertilizers, while beneficial for plant growth, does not address insect pest management and can sometimes exacerbate pest issues by encouraging lush, susceptible growth. Thus, the use of insecticidal soaps or horticultural oils stands out as a targeted and suitable method for managing insect pests in ornamental settings.