Kansas City is used to rainy spring days, but with so much rain in the forecast, you may have noticed something strange popping up on some of your trees.

It’s an orange or red, alien-looking form, that hangs out on cedar and apple trees.

The fungus is actually known as cedar apple rust and grows in galls, something that is similar to a tumor.

According to the U.S. Forest Service, the fungus is common in eastern parts of the country, but it’s also popping up in areas of the Midwest.

The cedar apple rust most commonly appears when eastern red cedar trees are near crabapple or apple trees.

The U.S. Forest Service said the fungus can be so prevalent on the tree, it can almost look like it’s decorated for the holidays. 

So, does cedar apple rust damage the trees and how do you get rid of it?

The rust is not harmful to people, but it attacks any fruit your tree may produce. The fungus can damage leaves and fruit, but it’s usually only a minor problem, according to the extension office at Oregon State University. Trees that have multiple infections or are already weak could eventually die.

“Rust diseases are rarely the nail in the coffin for deciduous trees but multiple years of defoliation due to rust disease can wear down a tree and cause it to decline,” Anthony Williams, district manager at Kansas City’s Davey tree office.

Williams said while the fungus won’t normally kill the tree, you also don’t want to let it get out of hand. He said the fungus can be treated in the summer, if wanted.

“Rust diseases need to be treated preventatively so if someone spots it on their trees they should contact an arborist to put together a plan starting at bud break the following spring,” Williams said. “In the meantime cleaning up leaf litter and disposing of it along with pruning to improve air flow through the canopy can help minimize the disease.”

Williams also suggests using a good fertilizer to help your tree recover from the fungus.