Cedar Hedge

(Question)

Hello, I recently planted 30 feet of 8′ cedars. It has been 2 weeks and a have been watering the cedars in the morning and in the evening. The area is an old neighbourhood with many hedges, lilacs and other trees on the property. When the hedges were planted, the soil was dug and loosened with a pick axe. The root balls on the hedges were a good size 12″ deep and 12″ wide/ round.
Watering this evening I noticed one branch had some browning tips. I looked closer at others I could see possibly others starting to get some browning tips.
There are also some yellowing / lesser green happening on some of the trees as well.
There are a few small broken branches that were damaged at some point during transport I am clipping those.
When I water there is some pooling but will disappear in 5 min.
I dug to see how moist the ground is and it is not muddy but well moist.
The hedges are also in a good amount of light throughout the day but not in blistering direct sunlight.
Am I watering too much? we have had quite alto of rain in the Ottawa area this year but less over the last 2 weeks.
Please Help

(Answer)

Thank you for contacting Toronto Master Gardeners.

New cedar hedges do take some care but there are some things you can do to increase your success.

Soil contains pockets that hold water and air, both are needed for a healthy root system. if the spaces are filled with water not allowing any air and oxygen to contact the roots the plants can essentially drown. This may be what you are seeing. If you water too frequently and the ground is always saturated the plants will not thrive.

There are a few guidelines to watering young trees. First you want to assess the level of moisture before you water. You need to stick you finger into the soil and  try to go about 2 inches deep to see how moist the soil is. If it is still moist that deep then watering is not yet needed. You will want to do a long slow soak so the water soaks deeply into the soil. Soaker hoses are a great tool for this. Less frequent long soaks that dry out between will encourage roots that reach out from the trunk and grow deeper. This will give better support and access more nutrients. Frequent shallow watering will encourage shallow roots that are less supportive and at more risk of damage.

You do not mention if you have mulched the hedge. A 4 inch layer of wood mulch ( not bark) along the sides of the hedge will help retain the moisture between waterings. Mulch will also help slowly loosen up the underlying soil and over time add nutrients to the soil and minimize weeds. you will have a healthier hedge  and soil by using mulch. When applying mulch make sure it does not pile up against the trunks. There should be a space between the trunk and mulch. The mulch should look more like a doughnut around the trunk rather than a volcano.

One more thing to check is that the cedars were not planted too deep. When you look at the trunk you will see a flair at the bottom where the root ball begins. The shrub should not be planted any deeper than the start of the root flair. None of the trunk proper should be below the soil as that will cause the bark to rot and eventually kill the shrub.

There are many questions about cedars hedges and their care in our library. I have attached links to two of them for your reference below.

Good luck.

https://www.torontomastergardeners.ca/askagardener/tending-a-new-cedar-hedge/

Landscaping with cedars