New growth following a forest fire.
The constant disturbance of mowing keepd the lawn from entering the succession process.
Plant communities grow and change over time through a natural process called succession. These patterns occur gradually over long periods of time. When a landscape is disturbed in some way, a general process of plant recolonization occurs.
The first plants to grow tend to be fast growing "pioneer" species that establish quickly on disturbed soils. Many plants humans consider weedy fall into this category. Given enough time, more complex plants such as herbaceous perennials, trees and shrubs will become established.
Most gardens are kept in a more or less relative state of ecological stability. The lawn is a great example of 'arrested succession'. Repeated cutting and fertilizer and herbicide applications keep other plants from becoming established. Maintained ecological stability reduces both plant and animal biodiversity in the landscape.
Creating an area in the landscape where succession is allowed to occur can be a great learning experience and can help connect the property to the greater landscape while increasing wildlife habitat and reducing maintenance.