Nimblewill - A Grass Native to North America

This grass is characterized by narrow blades, much narrower than most crabgrass, and similar in width to typical lawn grass.  It has a distinct growth habit though, different from lawn grass...it tends to have a little more space between blades, and the alternating pattern of its leaves is more directly evident.  This feature is more evident in the above picture on the right.

During the growing season, the leaves tend to have a distinct blue-green color, which is most evident in the above picture on the left.  The color is very blue, much bluer than the so-called "bluegrass".

Look for this grass in your lawn; it's most likely to occur in wet, shady areas with gravely soil.

The main reason people dislike this grass is that it turns brown in the winter, and turns green much later than other common lawn grasses.  It commonly seeds into and spreads within lawns of other, evergreen species of grass.  Especially in moist, shady areas that it is best suited to, it will out-compete other grasses during the growing season.

The only reason to dislike this grass is aesthetic.  The brown patches of this grass during winter and early spring are not dead zones--they're just a different color of the natural dormancy of this grass.  Other grasses stay green while staying dormant, but are still dormant during winter.

During the growing season, most people who I've pointed out this grass to say they actually like how it looks.  It has an attractive, blue-green color to the leaves and tends to grow in a neat habit.  It tends not to grow very tall, reducing the need for mowing, and it tends not to choke out flowers and other larger plants the way larger, thicker-bladed grasses often do.

A notable exception to this rule is California, where the grass is not native and is seen as an invasive plant.

Nimblewill is highly adaptable, but it prefers some types of conditions to others.  It does best in moist, shady areas, but unlike most shade-tolerant, moisture-loving plants, it can tolerate quite poor soil, including nutrient-poor, gravely soil.

I often see it growing together with mosses in the shadier parts of its habitat, and growing with various annual weedy plants in the sunnier range of its preferred conditions.  It can hold its own against other aggressively-growing plants, but it also leaves ample space for light to come through and it is frequent for other plants to be able to grow in or near it.

In cities it often grows up against buildings.  It also sometimes likes growing in wet spaces nestled up against the thick tree roots near the base of a large tree, where it frequently grows out of a dense carpet of moss.

The species of bug Stenodema vicinum feeds on the leaves of this plant.  In open areas, large herbivores feed on it.  According to its USDA Plants Profile, this species provides food for large herbivores as well as terrestrial birds (seed eating birds like sparrows that eat its seed).  The Lady Bird Johnson Wildflower Center's page on this grass recommends it as having interesting foliage and being good for attracting birds and valuable as forage for herbivores or livestock.