What factor is NOT typically influenced by the presence of weeds in a garden?

The presence of weeds in a garden can impact various factors that contribute to the health and productivity of plant life. Soil quality can be affected as weeds can compete with cultivated plants for nutrients and can even alter soil composition over time. Water availability may also be influenced since weeds can absorb significant amounts of water, potentially leaving less for desirable plants. Additionally, weeds can serve as hosts for pests, thereby potentially increasing pest populations that can harm cultivated plants.

In contrast, flower color is not typically influenced by the presence of weeds. Flower color is determined primarily by the genetics of the plant species and environmental factors specific to the cultivated plants, such as light conditions and soil pH. Weeds do not have a direct effect on the pigments or the genetic traits responsible for flower color, making this factor distinct from the others listed.