Why are my Arborvitae dying

Asked February 25, 2020, 6:43 PM EST

I have two of twenty Arborvitae pretty dead maybe root rot? Plants trimmed to approximately 12’ are in middle of row approximately 30 years Not sure best solution looking for suggestions pictures added they look worse from south better on north side

Snohomish County Washington

1 Response

So many questions... Do you recall the progression of the problem? Browning from the top down, or from the tips of the branches toward the inside? Was there some kind of damage that occurred to these trees but not the others? Is the watering the same for all 20 trees? Have you looked closely to see if there are tiny webs from spider mites? There are so many possibilities--I don't think this one can be solved online. Snohomish Co. has vibrant and well-educated plant clinic folks there. They would be better able to help you:

Master Gardener Hotline: 425-357-6010

Trained WSU Master Gardener volunteers are on duty to answer your horticulture questions from 9 a.m. to 4 p.m., weekdays, April through September, and from 11 a.m. to 3 p.m., Monday thru Thursday, October through March, except the week of Thanksgiving and the last two weeks of December. You may also leave a message outside those hours and a volunteer will call you back on the next work day. Call 425-357-6010.

Walk-In Diagnostic Clinic

Trained WSU Master Gardener volunteers are on duty weekdays to answer your horticultural questions weekdays at the Extension Office in McCollum Park in south Everett at 600 128th St. S.E., Everett, 98208. Hours are 9 a.m. to 4 p.m., April through September, and 11 a.m. to 3 p.m., October through March, except the week of Thanksgiving and the last two weeks of December. Bring in as fresh of a specimen as you can of the insect pest or the plant problem, which should include the diseased area, the transition area, and a healthy area, if applicable. Photos are also helpful. Please visit our “Contact Us” webpage for updates on operating hours, driving directions and more.

Community Plant Problem Clinics

Trained WSU Master Gardener volunteers conduct plant problem clinics at stores, nurseries and special events throughout the county during the growing season. At these clinics, Master Gardener volunteers are available to diagnose plant problems and give gardening advice. You are welcome to take plant or insect specimens to these clinics. For more information on the clinic nearest you, call the Master Gardener Hotline at 425-357-6010 or consult the MG Clinic Website to find a community clinic near you.