Sycamores fight back
Many area sycamores are displaying signs of anthracnose fungus delaying their leaf out or causing their leaves to turn brown and crinkle up. This "disease" is much more prevalent during times of cool, wet conditions like we experienced this spring.
The anthracnose fungus can inhibit leaf development by attacking young leaves as they unfurl. The leaves display a curled-up look and often have brown blotches along the midrib. If this damage continues, the leaves may turn brown and shrivel up, ultimately falling off the tree.
Once the mean daily temperature rises above 65 degrees, sycamore leaves will fully develop and, in most instances, a sycamore that has defoliated will put on a new set of leaves later in the summer. Most sycamore trees eventually grow out of this damage, but the damage may show up as clusters of dead twigs giving the branches a "witches broom" appearance.
Azaleas prefer well-drained acid soils in cool, shady areas.
Azaleas are in bloom now throughout the county. There are nearly 10,000 cultivars of this member of the Rhododendron family, with 14 native varieties recognized throughout the East.
They prefer well-drained acid soils in cool, shady areas. Most of the native azaleas found in Frederick County are located in the understory of oak forests. The azalea normally blooms in late April or early May and produces a drupe like fruit during late summer.
Azaleas are found throughout the globe and are cherished by many cultures. The Chinese name for azalea translates to "the royalty of gardens." The Koreans produce a wine from the azalea blossom. In mythology, the azalea was the flower of Sagittarius.
Japanese barberry (Berberis thunbergii) is an ornamental that has spread into our open areas and become an ecological threat. It is an example of an exotic, "invasive" species, meaning that this non-native plant invades natural areas and displaces the native vegetation.
What makes barberry problematic is that it can grow in shady conditions, so it can aggressively spread throughout native forests. Barberry is a dense, deciduous, spiny shrub that grows to a height of about 8 feet. The branches have a sharp barb at the end of each node. A yellow cluster of flowers appear on the plant in early May and a red fruit develops in the fall.
Barberry is a prolific seeder, and the plant can be spread by birds that consume the fruit. Barberry can also spread vegetatively from cuttings or from stolens coming off the plant.
Once barberry gets established, it can form dense stands and make the forest almost impossible to access. This plant does not offer much nutritional value or cover to native wildlife, so infested areas loose their wildlife value. Barberry can also disrupt forest development if it excludes the young trees, shrubs, and herbaceous plants that would otherwise be found there. It is also thought that barberry raises soil ph and could produce chemicals that kill beneficial soil bacteria, thereby making the soil less productive.
For these reasons it is recommended that homeowners not plant non-native Japanese or European barberry as ornamentals and that forest landowners consider controlling any infestation of barberry on their property. There are a number of informative web-based articles on barberry control, including the Plant Conservation Alliance's PCA Least Wanted series at www.nps.gov/plants.
Article by FCFCDB
Nature Notes for 5/23/2010