Help your trees transition to autumn

“There’s not much difference between desert trees and desert-adapted trees,” says Ken Busse of the Davey Tree Expert Co. “They need the same care and attention to remain healthy, despite the season. We’re lucky in Southern Nevada because we don’t often have the freezing temperatures, but we do have the extreme temperatures throughout the summer.”

Busse serves as district manager of the Las Vegas residential/commercial office of the Davey Tree Expert Co. and has over 30 years of experience in the green industry. He’s an International Society of Arboriculture Certified Arborist and a Tree Care Industry Association Certified Treecare Safety Professional. His advice to get your plants well-situated for the changing seasons comes in handy this time of year.

Busse shares that one of the most important things plant and tree owners can do is ensure that their irrigation system is working properly.

“People watered like crazy here in the 1980s and 1990s, and today, we are seeing lots of the turf from that time period being removed,” Busse says. “While removing turf can make a big difference in our overall water usage, there are also consequences for those actions.

“Many locations that used to have grass are now concrete or are covered in rock, and it just doesn’t help the trees, like mulch does in other areas of the country. Plants don’t necessarily need more water; they just need it utilized in a better manner.”

He explains that plants constantly are developing roots and will often grow large amounts of upper foliage. However, while that’s happening, the underground root system is growing on top of itself and the air spaces become overgrown, so plants can’t get the air and the roots don’t have enough space. As you water these trees and plants, the liquid keeps working its way down to the roots and eventually into the aquifers.

“You put water at the base of a plant because you want that plant to grow in that one spot,” says Busse.

Another area of major focus in this urban environment should be the fertilization of your trees.

“Because we tend to remove the organic matter that falls from trees, we don’t give it time to break down and fertilize naturally,” says Busse. “That means we need to add fertilizer to the soil.”

While some people tend to fertilize at random times of the year, Busse says that any time is right for fertilizing.

“Follow the directions on how often to apply the specific type of fertilizer you have,” he says. “You can fertilize a little bit every single day if you want to; the plants are constantly trying to absorb the nutrients from the soil.”

He says that the trick is to really incorporate the fertilizer down into the soil and the best way to do that is by digging down and mixing it into the soil below the ground. “Using granular fertilizer on top of the soil is really not very effective.”

Busse notes that when visiting other places in the country, you’ll often notice trees that are much older than those here.

“Our oldest trees barely make it to 40 or 50 years old because of our environment,” he says. “Fertilizing properly can help them live longer.”

Busse also stresses the importance of pruning. “As it starts to cool down in the fall evenings, trees and plants begin to recover and grow again. The damaged material needs to be pruned out three to four times a year.”

He suggests that it’s better to prune lightly more frequently than waiting to do a big annual or semi-annual heavy-duty pruning.

Taking constant care of your trees means that you can mitigate pest nuisances, such as borers, and harmful diseases, such as canker.

“Borers are the larvae of different kinds of beetles and eat away at a plant’s tissue,” Busse says. “They can often cause extenuating circumstances that are sometimes non-recoverable. However, borers rarely infest healthy plants vigorously growing in their natural environments.”

Canker, on the other hand, is a fungus that enters a tree and grows between the bark and the wood, thereby killing the bark. According to the Morton Arboretum (https://mortonarb.org/plant-and-protect/tree-plant-care/plant-care-resources/canker-diseases/) , these diseases are common, widespread and very destructive to a wide range of trees and shrubs. A canker is really a symptom of an injury often associated with an open wound that has become infected by a fungal or bacterial pathogen.

Canker diseases frequently kill branches or structurally weaken a plant until the infected area breaks free, often in a wind storm in Southern Nevada. Cankers can also be caused by damage from weed eaters, lawnmowers, chemicals, insects or environmental conditions.

When should a homeowner call a professional for help with their trees?

“Any time you’re unsure of what to do, call an expert,” Busse says. “Just like you do with your car, appliances and other parts of your home, the outdoor living area should be regularly inspected. Experts like landscapers and arborists can determine if there are irregularities in your irrigation system — such as broken valves — that need to be fixed for maximum efficiency.”