Pretty, green and a problem

One of the most common invasive plants in the Eastern U.S., Japanese stilt grass is easily mistaken as a pleasing, bright green grass ground cover. Its lance-shaped leaves can be recognized by the silvery center stripe with hairs down the middle.

Although an annual, stilt grass reproduces quickly through prolific seed production, following its bloom in mid to late September. It is best mowed for control while in bloom, before the seed has developed. Since stilt grass seeds remain viable in the soil up to seven years, annual control for many years is required to remove it.

Japanese stilt grass is thought to have come to the U.S. as packing material in the early 1900s. It thrives in a variety of light and soil conditions, taking hold in disturbed areas, including the heavily deer-browsed forest floors in Frederick County. However, deer and other grazing animals are reluctant to eat it. When it takes hold in the understory, it out-competes the native plants and reduces the habitat preferred by native birds and animals.

Photo courtesy Wisconsin Dep’t. of Natural Resources, by Elizabeth Czarapata

Japanese stilt grass reproduces quickly through prolific seed production, following its bloom in mid to late September. It is best mowed for control while in bloom.

BACTERIAL LEAF SCORCH

The symptoms of bacterial leaf scorch have been showing up in area trees over the last month or so throughout the county. It is an infectious chronic disease spread by leaf-feeding insects like leaf hoppers and tree hoppers. It attacks the tree’s water transport system, called xylem, and disrupts water transport to the leaves, stems and roots. Diseased trees will produce healthy-looking leaves at the start of the growing season, but the margins of leaves will turn brown as the season progresses in late July and August.

The brown area will be separated from the green growth on the leaf by a yellow or red band, often called a halo. Unless treated, BLS will cause the slow decline and death of the tree over two or more growing seasons. It is not a new disease but it has become more common.

SNAKE SIGHTINGS

Numerous reports of venomous snake sightings have occurred across the county over the last month or so. In this area, two common venomous snakes are found — timber rattlesnake and copperhead.

According to Scott Smith, a herpetology expert with the Maryland Department of Natural Resources Wildlife Division, there are a number of reasons for the recent sightings. Females are now giving birth to their young, which are born alive instead of in eggs. You may observe a pregnant female that cannot move much or spot groups of newborn snakes. Also, snakes are making their way back to their dens, so they are more mobile now, rather than sedentary as they usually are throughout the summer. Finally, the drier conditions of July and August may be causing these reptiles to travel farther in search of food.

Spotting a rattlesnake is a somewhat rare occurrence, as these snakes prefer dry, rocky outcroppings, which are usually far off the beaten path. Copperheads, on the other hand, are more numerous and found in a number of areas. Copperheads use camouflage as a defense to avoid contact with people or other animals that would harm them. Neither is very aggressive, although they will defend themselves if stepped on or attacked. Snakes, like any other wild animal, should be left alone.

Photo by Mike Kay

In this area, two common venomous snakes are found — timber rattlesnake and copperhead, above.

JEWELWEED

Jewelweed is blooming now. It is part of the impatiens family, and is also known as touch-menot, because its mature seed pods will “explode” if touched. This trait helps disperse seeds distances of 20 feet or more.

Jewelweed is a native annual plant that is well distributed throughout America and was introduced across Europe during the last few centuries. It is a common plant found in moist rich soils throughout the region. The leaves, when wet, refract light like a prism and shine like silver. Jewelweed has been used as a home remedy for insect bites, bee stings and poison ivy.

Nature Note for 9/28/2008