Q: Can you find out what is wrong with my arborvitae? They were planted last spring. Some are OK, but others have random browning. There is some new growth, but they don’t look the best.

• Skip from Boardman

A: Skip is one of several calls we received this spring and early summer relating to arborvitae planted last spring. Some gardeners provided samples. We reviewed the samples and reviewed them under the microscope. We did not find any signs of insect damage or disease.

This is an environmental issue. Arborvitae are shallow rooted plants. Thus, they need watered consistently during at least the first year of planting — and especially during anytime we do not get at least 1 inch of rain per week. The browning of tips in spots is due to lack of adequate moisture available to the tree.

We tend to have dry spells. Sometimes, these happen in summer and we realize we need to water. But many times, this happens in fall or early winter. This is the time of year we need to pay more attention to our shallow rooted evergreens — as they need the water.

So, what can be done right now?

1. The browned tips can be pruned out back to green growth or where you see green tissue by scratching off bark towards the end of the browned needles. New growth has already emerged for the season, but the area will continue to fill in over time.

2. Monitor soil moisture by watering slowly and deeply to encourage deeper roots. Arborvitae tend to have shallow root systems, so this is even more important for them. Watering with drip irrigation is best, but also bucket / bag watering that drips slowly into the soil will work.

3. Don’t forget about fall and early winter watering for small evergreen trees and evergreen shrubs. In our area, the average soil temp stays above 40 until late December, so water can be added through that time if mother nature does not supply.

4. Be sure you have 2 inches of mulch on top of the soil to conserve soil moisture. More than that amount can be detrimental for the trees and lead to other root issues. Watch for the squirrels and chipmunks that remove mulch and be sure to replace it throughout the year when it has been removed.

To learn more, go to http://go.osu.edu/latefallwater and http://go.osu.edu/winterwater.

Call 330-533-5538 to submit your questions to the plant clinic 9 a.m. to noon Mondays and Thursdays through October.