When this can't be done, fungicide treatment may be necessary. Mites and white fly are less of a problem when plants are frequently watered.
High temperatures increase insect populations necessitating more frequent pesticide treatment.
Use extreme caution with pesticides. These pests can feast on young bedding plants, especially marigolds, petunias and salvia. Place slug bait near new plantings in late afternoon and replenish as needed. Lightly sprinkle the baits to avoid eating by wild or domestic animals. Be sure to remove weeds as soon as possible so they do not compete for water and nutrients.