Trees, like humans, get sick. They "catch a bug" and often it's literally a real bug--an insect or spider. The ALCC has written this timely article on how to diagnose plant problems. If you think your plants may be needing that extra help to recover, call us or your trusted arborist.
As with people, the cure for plant problems lies in the diagnostics. Chemo doesn't cure a cold and an aspirin won't cure cancer. The treatment has to fit the health issue and that starts by identifying exactly what you're really dealing with.
This summer has brought a variety of bugs to trees along the Front Range that demonstrate the range in treatments that may be required to keep our trees healthy. Most of us want to avoid taking pills when they are not needed. Yet we know that without antibiotics, pneumonia may be lethal. Other times, we have to make a judgment call on how far we're willing to go to treat a particular bug or disease by weighing all the factors.
So it is in the plant health world. Aphids for example, are mostly more of a nuisance than a threat to long-term plant health. If they are really bad on the rose bush, you can simply spray the leaves with a mixture of Ivory soap and water. Releasing natural predators like lady bugs is another low-impact treatment option. Because arborists agree that aphids are generally not a major threat, whether or not you treat them really comes down to your own tolerance level for the unsightliness and the mess.
On the other end of the spectrum, this summer has seen a continuation of the infestation of Thousand Cankers Disease (TCD) which is carried into black walnut trees by a beetle that bores into the bark and beyond. Sadly, there is no known cure for this disease and we have seen many dead trees this year to prove it.
In between the aphid and TCD scenarios, we have the encroaching infestationMountain Pine Beetle which is in the must-treat category. If you want to save the tree, the bug has to be treated and timing as we have noted in previous Tips, is everything. Like getting a flu shot, being treated ahead of the onset of the bug is critical. But unlike the flu shot, treatment is not optional. Proactive treatment with the pesticide that treats Mountain Pine Beetle is required to save threatened trees.
Arborists also remind us that promoting health in trees is on a parallel track with promoting health in humans. Building up the immune system is critical. Weakened, injured, stressed trees are more likely to succumb to their equivalent of the flu bug. Limbs torn in a wind storm that have not had remedial pruning afterwards are an invitation to insect infestations and disease. Trees stressed from too much--or too little--water will also give in more quickly to insects and disease.
And the opposite is true. Trees that are given adequate water, remedial and structural pruning, and proper fertilization will be less inviting to bugs and less susceptible to disease.
If you want to take fewer aspirin for headaches, do the things that keep headaches at bay. If you want to reduce the treatments needed on your trees, do what it takes to keep them healthy, too.
Source: ALCC Tip of the Week 08-12-2011