What type of herbicide is best for perennial weeds?

Systemic herbicides are the best type for controlling perennial weeds because they are absorbed by the plant and circulated throughout its entire system, killing the entire plant including its roots. Residual herbicides only prevent new weeds from growing and are not effective on established perennial weeds. Selective herbicides only target specific types of plants and are not ideal for controlling a variety of perennial weeds. Non-selective herbicides kill all types of plants and are not suitable for use in areas where other desired plants are present. Therefore, systemic herbicides are the most suitable option for effectively controlling perennial weeds.