American holly (Ilex opaca) and English holly (Ilex aquifolium) are prized for their glossy, green leaves and brightly colored fruit. Sprigs of both hollies are often used in wreaths, centerpieces, and other Christmas…
Deer may feed on trees and shrubs during the winter months and severely damage or destroy plants. Damage is most likely to occur when food is scarce during prolonged periods of snow cover. Deer often feed on the foliage on the lower…
The brown growths in your ash tree are probably ash flower galls. Galls are abnormal plant growths induced to form by small insects, mites, or other organisms. On ash trees, a tiny mite causes the male flowers to develop into roundish…
The Emerald Ash Borer (EAB) is an exotic destructive pest that kills all native ash trees (Fraxinus). The loss of ash trees significantly impacts the urban tree canopy. While treatment options are available, some trees cannot be treated…
The poinsettia (Euphorbia pulcherrima) is native to Mexico. In Mexico, the poinsettia is a large shrub or small tree that may reach a height of 10 to 15 feet.
Poinsettias were cultivated by the Aztecs, who called the plant…
Winter (December through February) is the best time to prune oak trees in Iowa. Pruning oak trees in winter greatly reduces the risk of an oak wilt infection.
Oak wilt is a fungal disease that is lethal to many oaks. It…
One of the most beautiful sights in winter is the bright red twigs of redosier dogwood (Cornus sericea) set against a backdrop of newly fallen snow. Native to Iowa, the redosier dogwood grows 6 to 10 feet tall. Several colorful varieties…
When attempting to attract birds to the landscape, trees and shrubs that provide food during the winter months are extremely important as natural foods are most limited at this time of year.
