Browning, crowded, cedar hedge

(Question)

I purchased a home with a ceder hedge in my backyard 6 years ago. 15 trees were planted too close together. The trees get enough sun and rain coverage. I’m in zone 6. I think the soil is loam. For the first time I am concerned to see that there are patches of brown developing on many of upper areas on the trees and some loss of foliage.
This week I added 4 bags of a 3 in one soil mixture of compost & peat moss, along with a ceder specific fertillizer for tree (step2: maintenence) to the hedge line. I topped up with one bag of organic compost with worm castings.
I don’t want to lose any more green or risk developing loss of any more of the trees’ fullness. Could you advise me of the best route to reviving my trees? Thank you! I tried to attach a pic but there is a problem with your site’s upload.

(Answer)

We receive a number of questions concerning browning cedars. It is normal for cedars to have brown leaves in the spring or fall, and we’ve had a particularly harsh winter, with lots of wind, and several freeze/thaw cycles, which could contribute to the cedars drying out – and leaves browning.  Less likely but also a possibility is that the brown patches could mean that a disease (e.g., fungus) or pests are at work.

You seem to be doing everything right – the hedge gets lots of sun, water and you’ve just given it a boost with fertilizer, which will help it get a head start as the growing season approaches.  However, you do mention that you feel the trees were planted too close together – this could be a concern as if there is not sufficient air circulation between the trees, diseases and insect pests are more likely.  However, the brown areas you describe seem to be at the tops of the trees, as opposed to between the trees, where one would expect crowding to cause problems.

See The Spruce’s Why is my arborvitae turning brown? 

As well, consider searching on our website for “cedars” and “brown” and a number of entries will pop up.  One is particularly helpful, Dying and browning emerald cedars.

Be kind and patient with your hedge, keep taking great care of it and please report back to us later in the season as to how it fares!