Frequently Asked Questions - Evergreens

The majority of roots, especially those roots that are responsible for water and nutrient uptake, are in the upper 6 to 18 inches of soil.  Structural roots that radiate out from the tree and provide support and anchorage can reach a…

The roots of trees continue to grow until the ground freezes.  If the weather is dry, continue to water the newly planted trees until the soil freezes in winter.  
 

Variety and cultivar are two terms often used interchangeably by gardeners and horticulturists, but they are not the same thing.

Both are part of the scientific name. Both appear after the specific epithet (second term in a scientific name…

While all trees have unique issues, some problems are more commonly encountered than others

Many issues seen in trees are due to improper environmental factors.  Even when insects or diseases are present, the primary cause may have…

Bagworm caterpillars can cause damage by defoliating spruce, cedar or arborvitae trees.

Bagworm insecticides such as Bacillus thuringiensis, spinosad, Sevin, permethrin or bifenthrin will be ineffective and a waste of time if they…

Only a small number of evergreen trees perform well in Iowa.  Some evergreens, such as Scotch pine (Pinus sylvestris), Austrian pine (Pinus nigra), and Colorado spruce (Picea pungens) have serious disease…

Native deciduous shrubs that can be successfully grown in partial shade include,

Deciduous shrubs that grow well in dry locations include,

• Devil’s Walking Stick (Aralia spinosa)*
• Bearberry (Arctostaphylos uva ursi)+
• Red Chokeberry (Aronia arbutifolia)*
• …

The browning of the inner foliage is probably due to seasonal needle drop. It’s normal for evergreens (pine, spruce, fir, juniper, arborvitae, etc.) to shed their oldest (innermost) needles in fall. The innermost needles gradually turn yellow or…