Treatment for Pests and Diseases
Overall tree care starts from below the ground at the root system. As we all know Colorado soils in most neighborhoods could be better; we have nutrient deficiencies up and down the front range. Colorado soils are very alkaline (clay) in nature and tend to lock up nutrients making them unavailable to our trees and shrubs. When these micro and macro nutrients become unavailable to plants they stress. When plants stress, insects and disease move in to do what nature intended them to do which is to accelerate the decline of the stressed plants until mortality occurs. Actually insect and disease problems are secondary, the problems normally start below the ground. This is why it is so very important to look down as much as we look up. Introducing beneficial microbes along with slower release fertilizers are a common practice in our environment. Please remember, “always consult a professional”. Fertilizing stressed trees or shrubs is not a good idea. What is a good idea is to always remember the first line of defense in Colorado is hydration; water, water and more water. (Though do be careful not to over water.)
I have seen infestations over the last 25 years where chemical treatments are the only option. They do have a place in our toolbox and here are some examples:
IPS Engraver and Mountain Pine Beetle:
These tiny winged beetles have long been killing sickly trees in North American forests. But in recent years, they’ve been working overtime. Prolonged droughts and shorter winters have spurred bark beetles to kill billions of trees in what’s likely the largest forest insect outbreak ever recorded, about 10 times the size of past eruptions. “A doubling would have been remarkable,” Six says. “Ten times screams that something is really going wrong.”
Mountain Pine, Spruce, Piñon IPS, and other kinds of bark beetles have chomped 46 million of the country’s 850 million acres of forested land, from the Yukon down the spine of the Rocky Mountains all the way to Mexico. Yellowstone’s grizzly bears have run out of pine cones to eat because of the beetles. Skiers and backpackers have watched their brushy green playgrounds fade as trees fall down, sometimes at a rate of 100,000 trunks a day. Real estate agents have seen home prices plummet from “viewshed contamination” in areas ransacked by the bugs. And the devastation isn’t likely to let up anytime soon. As climate change warms the North American woods, we can expect these bugs to continue to proliferate and thrive in higher elevations—meaning more beetles in the coming century, preying on bigger chunks of the country. *(By Maddie Oatman – Mother Jones published in 2015.) In 2017 IPS has been making a comeback and more trees in the Denver Metro area have been affected.
Emerald Ash Borer:
Approximately 15% of the trees that make up Colorado’s urban forest are Ash. There are an estimated 98,000 in the City of Boulder alone. The Denver Metro area has an estimated 1.45 million Ash trees. EAB is responsible for the death of over 25 million Ash trees in the United States.