You may want to give your trees a drink of water. Especially if you have noticed dried dead branches.
One of the warmest and driest fall and winter periods in years has resulted in the rapid onset of drought conditions across Northern and Central Arizona, according to the National Weather Service in Flagstaff.
Relief is unlikely until the monsoon season arrives later this summer, according to NWS, adding that southern Yavapai County is in an extreme drought.
“When we have a dry winter, lots of trees die in the Verde Valley,” explained Jeff Schalau, agent for the Agriculture and Natural Resources for the University of Arizona Cooperative Extension in Yavapai County for the past 20 years.
Evergreens are taking the biggest hit, said Schalau, adding that most of the fruit trees in the Verde Valley are being irrigated.
Many people don’t water trees in the winter, Schalau explained, or don’t think that native Arizona trees like the Arizona Cyprus need to be watered. In a winter such as that experienced in 2018, it makes a difference.
It’s tough to generalize what’s killing trees after a dry winter, said Schalau. Almost always there’s a pest involved that finishes off the plant. He said he said he is getting lots of calls about pests and dry trees.
Drought predisposes trees to other problems; and then other problems occur and kill it, he said. But the pest damage is secondary to drought damage.
The forester said he was just in Dead Horse Ranch State Park in Cottonwood examining pine trees, and he saw no evidence of bark beetles, but at the same time limbs were dying on the trees. He thought it was just associated with “not enough water.”
“It’s been a long time since significant rains,” he said.
The high temperatures last summer stressed a lot of trees locally and caused them to shed branches.
Schalau explained that it’s not enough to put a garden hose at the base of a tree and water it. Roots grow away from the tree and need moisture to stay alive. The drip line is the vertical projection of the canopy, he said. It’s had to tell where the roots are on older trees. To prevent water from running off, he suggested putting in a drip hose around the crown line, or a small ditch around the drip line.
Schalau said people need to provide the correct amount of water to meet the needs of a particular tree, taking in consideration the soil and season.
Some trees like mesquites can tolerate drought and don’t need to be watered much at all, but pine trees are going to need water all through the winter.
“Any evergreen needs water all year long,” he advised.
Fruit trees can be irrigated one or two times a week the summer and every two weeks depending on the soil, he said.
Lindsey Cure from Verde River Growers in Cottonwood said she has noticed certain fruit trees that haven’t come back this year, and some people are having trouble with established trees.
Because there was little rain last year, people should allow for a slow soak on plants and trees, but even Cure said she was a victim of losing a plant she had for 20 years.
Plants and trees that are not hydrated are weaker and more susceptible to insects such as beetles, she pointed out. “You want to be looking at them more.”
Cure said to clean out the dead branches.
Young fruit trees are seeing most problems this year, she said, especially apricot trees. Many people said they didn’t get blooms on their trees this year so there won’t be fruit production.
“We went like 120 days without rain this winter,” Cure pointed out. If you had irrigation, you probably had blooms and you may get fruit, she added.
Cure said fruit trees should be on some kind of irrigation going into the summer – every day if they are new and every other day if they are established.
Huge pines and junipers need to be done on a slow soak with those hoses that go all around the tree to water roots, she said.
She also recommends watering at night when temperatures are cooler and you don’t get as much evaporation.
Cure has not seen many people coming in yet to replace drought-hit trees, but she thinks people are just beginning to see the damage.
“If you’re not getting water, how are you going to grow things,” Cure said.