December 13, 2019
Blue spruce trees are one of the more popular conifers used in landscaping. These lovely trees are characterized by their visually striking form with gorgeous blue foliage and their superior growth rate. The only problem is blue spruce trees are susceptible to an array of disease and insect threats that compromise their aesthetics as well as growth. Unfortunately, the frequency of blue spruce tree disease is increasing as time goes on. In particular, branch dieback is occurring much more frequently than in prior years. The combination of canker diseases with other diseases and insect issues will likely continue to plague spruces well into the future.
The Problem of Needlecasts
Needlecast diseases are those that cause spruce trees to shed their needles. The most common versions of needlecasts found in spruces are the result of fungal pathogens dubbed Stigmina and Rhizosphaera. Needlecast fungi commonly infect needles on the shoots. The disease advances to the point that the needles perish. Needles typically die about a year after the infection. Spruces compromised by needlecasts typically have an exterior shell consisting of live needles along current shoots and perished needles along older shoots.
The Rise of Canker Diseases
Canker diseases result from fungus infections along the primary stems of trees. Canker symptoms typically include sunken spaces on the stem that emit resin. It is also possible for spruce trees to generate ridges of wounded tissue near aged canker infections. These ridges are the result of the tree attempting to minimize the growth of the fungus. The development of the canker interferes with the ability of the branch to transmit water as well as nutrients, leading to the death of branches.
Tip blight is a fungal disease that commonly results in dieback to shoots that have recently emerged. Tip blights are particularly common on pine trees yet they also occur on blue spruces.
How to Handle Threats to Your Spruce Trees
If you suspect anything is wrong with your blue spruce tree, your best course of action is to determine the exact problem and pinpoint the cause of that problem. If the tree is particularly large or important to your property’s landscape, reach out to a landscape contractor for assistance. If there is a disease problem such as needlecast, the best course of action might be the application of a fungicide. The timely application of fungicide will help prevent the onset of the disease or at least control it. However, it must be noted needlecast fungicide treatments only safeguard new growth.
In order for the control to prove successful, it might be necessary to apply fungicide for several years. If the problem is a canker disease, fungicide might be only partially effective. The better course of action will be eliminating affected branches so the tree looks better and the disease is slowed. Above all, you should provide your blue spruce trees with conditions that favor their growth. Ample sunlight, sufficient soil drainage, and consistent air movement will enhance the chances of healthy growth.
Continue Planting Spruce Trees, Albeit in a Strategic Manner
Though spruce decline is real, it does not mean you have to stop planting blue spruces. The bottom line is not all spruce trees will be impacted. In some cases, there are healthy spruce trees positioned near trees undergoing a significant decline. Furthermore, plenty of spruce trees will prove healthy for years prior to showing any signs of decline. Continue to plant your blue spruce trees as you have in the past, make the alterations detailed above and your spruce trees will thrive. If you have questions about spruce trees or are interested in learning what the best trees are for your own landscape, contact us today.
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