March 22, 2006
Swiss needle cast is a fungal disease that causes needle discoloration on Douglas fir trees. Symptoms are usually most visible on the inner portions of lower branches, where infected needles turn yellow-green and brown and then fall off. Tiny black fruiting structures of the fungus can be seen with a hand lens, appearing as black dots in two rows on the undersides of discolored and some green needles. Affected branches typically look sparse.
After a long, drab winter, most gardeners anxiously await the arrival of spring. One sure sign that spring has truly arrived is the bright yellow flowers of the forsythia. Named after William Forsyth, an 18th century Scottish horticulturist, the forsythia is a deciduous shrub that is native to China, Korea, and Europe.
In Iowa, forsythias typically bloom in early to mid-April. The four-petaled flowers vary from light yellow to bright golden yellow and persist for 10 to 14 days. Flowers are produced in groups or clusters along the stems. Forsythias bloom only on old wood.