Coming home to a well maintained property makes people feel good. Corporations have learned that beautiful and functional landscapes around their buildings make it easier to attract good employees, and that it has a definite effect on their reputation with their customers. Weeds in the landscape detract from the beauty of landscape plantings, and disrupt the effect of good landscape designs. Weeds can also have a negative effect on the reputation of businesses. Golf courses or commercial properties that have weed infested landscape plantings are often assumed by clients to be careless in other business related practices.
Weeds compete with ornamentals and turfgrass for water, nutrients, and light.
The effect of weeds can be especially dramatic in draught years, when weeds can greatly reduce the growth of ornamentals. Some weeds, especially grasses, are also allelopathic. This means they produce chemicals which inhibit the growth of other plants around them. Quackgrass is known to be allelopathic, and all of the cool season grasses are suspected of being allelopathic to woody plants. The most common problem related to allelopathy in landscape plantings is cool season turfgrasses growing right up to the base of trees.