Extended drought followed by heavy rains are causing root instability. Trees aren’t just failing, they are falling over.

“The ground can become like Jell-o once the soil gets to field capacity,” says Daniel Goyette, principal arborist for the Huntington Botanical Gardens.  “It can no longer hold any more water. That’s where you get movement in the soil. It’s why trees are toppling —  the soil does not have the rigidity that it usually does.”

So how do you know if your tree is in danger?

Arborist Rebecca Latta  recommends looking for changes in the soil near the tree’s roots. “If I see cracking in the soil next to the trunk, then I am very concerned,” she said. “Especially if the homeowner says it is new. That indicates the tree might be moving.”

Goyette advises calling a certified arborist when you see dead branches or notice that the crown of the tree is thinning out. Fungal masses growing at the base of the tree or other sections of the tree are another red flag for homeowners. “It’s an indication that there is wood decay present,” he said.

In some cases, trees fall over due to something that took place long ago. “It could have been construction or landscaping,” said Goyette. “There could have been a patio or a porch or irrigation work. The roots could have been severed 30 years ago.”

She also says the best way to protect roots going forward is to try not to encroach on them by putting a lot of plant material next to the trees. She says the best food for a tree is its own leaves decaying underneath it.”

Horticulturists recommend avoiding excessive pruning, especially at the crown of the tree. Pruning can put a tree into a tailspin. It can cause a tree to go on a starvation diet.