Junipers Damaged by Mice

PULLMAN, Wash. — Concerned homeowners in the Pullman area have been calling Washington State University about dieback in juniper shrubs.

“It seems worse on Tam junipers,” said Kurt Schekel, WSU horticulturist. “I’ve occasionally seen it in on Pfitzers. It’s a branch here or there but not big mass of branches.”

Both varieties are used as groundcovers.

Mice and snow are the culprit, according to Schekel. “Bush junipers like the Tam and the Pfitzers provide a lot of protection for the mice. When the snow gets bad, they’re stuck there. When they get hungry, they eat the bark.”

The rodents girdle branches close to the ground, some as large as a half- inch in diameter. When temperatures start to rise and the ground begins to dry out, damaged branches turn brown.

What should homeowner do?

“Just about the only thing you need to do is prune out the dead stems,” Schekel said. “It’s a visual problem more than anything.”

And about the mice?

“The mouse population goes in cycles. I’m sure they’re still there, but I haven’t seen a mouse in a long time. However, last winter they were thick.”

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