With the correct grass type for the area under proper soil conditioning, fertilization, watering, and mowing, the lawn environment will be unsuitable for the indicator plants and the community of grass plants will be dense enough to exclude opportunistic weeds.
(the lawn environment; will be; unsuitable for the indicator plants and the community of grass plants) (the lawn environment; will be; dense enough to exclude opportunistic weeds)
the lawn environment the lawn environment
will be will be
unsuitable for the indicator plants and the community of grass plants
dense enough to exclude opportunistic weeds