It’s crazy to think that it’s already a new year! 2014 brought some unexpected surprises and exciting opportunities for Swingle, and we’re looking forward to 2015. As we move into the new year, Swingle is predicting emerald ash borer and the November 2014 freeze will impact our Colorado landscapes in 2015.
Discovered in September of 2013, emerald ash borer has yet to be found outside of Boulder, Colorado, but no one knows how fast it will spread to surrounding communities. During this past summer, some important developments transpired:
- The entire City of Boulder is now considered infested with emerald ash borer.
- Many trees over several city blocks are symptomatic of borer infestation and dying.
It’s estimated that Emerald ash borer has probably been feeding on ash trees in Boulder for approximately 6 years. Emerald ash borer is unquestionably the worst urban landscape pest to reach North America and now this insect is ready to take off in the Front Range. Will the next discovery be in 2015 or 2016? We believe within the next 18 months, the borer will be discovered outside of Boulder and immediate actions will be needed to save ash trees. We are taking a proactive approach to protecting our urban forest and recommending treatment, after an expert evaluation.
Mild temperatures during the fall of 2014 came to an abrupt end in mid-November. The high temperature on November 10 was 64 degrees. The night of November 12, the record low temperature was -13 degrees. This represents a 77 degree change in temperature in 3 days- the 3rd greatest temperature drop ever recorded in Denver since 1872.
When the freeze hit, many plants still had foliage and some had not fully hardened off for winter. Initially we thought our landscapes would not be negatively affected until the spring of 2015, but after just a few weeks, damage became evident. The south sides of our spruce and pines turned a bleached, straw color and junipers turned bronze. Many shrubs, fruit trees, and especially roses are also showing signs of freeze damage, with brown, shriveling twigs.
Brown leaves clinging to these trees may also indicate damage. A skilled arborist can check the buds and tissue below the bark in young shoots to see if these plant parts are viable. We will have to wait for spring to see how our damaged plants respond.
Pine Wilt Nematode
In states just east of Colorado, they have lost thousands of Scots and Austrian pines to pine wilt. A wood boring insect (pine sawyer) spreads a tiny worm-like animal called a nematode to healthy pine trees. The nematode multiplies and clogs up water conducting tissues. In the late summer and fall, infested trees die rapidly. In 2012’s unusually hot summer we experienced a definite uptick in loss of trees. The good news is that in both 2013 and 2014 moderate summer time temperatures, as well as above normal rainfall, dampened the nematode’s destruction. In 2014, we did diagnose a few trees with pine wilt, so the nematode is still active in our area. With a hot spring we could see many pine trees die in the fall of 2015.
For those of you from the eastern United States, you might be very familiar with this insect. Japanese beetle needs consistent soil moisture to mature- especially in the winter. The winter of 2013 and 2014, we had some abundant moisture and had a definite uptick in the summer of 2014 Japanese beetle activity. Japanese beetle feeds on plants such as roses, Virginia creeper (vine), linden trees and many other ornamentals. Adult Japanese beetles chew and defoliate plants in the middle of the summer. If this winter continues with consistent moisture, be on the lookout for Japanese beetles in early July.
Throughout the 2015 year, Swingle will be staying on top of all pest detections. As information develops and discoveries are made, we will continually provide information about pests in our area and the best treatment options available for protecting your Colorado landscape. Our experts are always available to provide a free consultation, so please take advantage.