I have 40 emerald cedar trees about 2 to 3 years old and 6 feet tall.About 12 trees have gone brown and died. please advise how I can save the rest. Mississauga area
Thank you for your question. We do get many questions about Emerald Cedars.
These cedars are very popular, often used as a privacy screening around houses. We frequently get asked the same question about cedars turning brown especially after the winter season, so as a result we have a lot of information on our site about emerald cedars. You may wish to log into the “Ask a Master Gardener” website using “emerald cedar” to find lots of useful information about this popular evergreen.
These trees require lots of water and need to be watered thoroughly on a regular basis and the roots not allowed to dry out, especially if our summers have been extremely hot and dry. We also suggest the use of a drip irrigation hose which allows the ground to become soaked down to root level. Lack of proper watering will produce browning on the tips, and eventually the entire plant.
Winter injury or burn occurs when winter winds dry out the evergreen leaves. When the soil freezes the winter winds draw moisture out of the evergreen leaves because the plant roots are unable to take up water from the frozen soil to replace what has been removed from the leaves.
Watering them well prior to winter is very important but they need to be watered until freeze up to prevent winter desiccation.
You may wish to apply a fertilizer in early spring to encourage new growth. Evergreens require a lot of nitrogen so 30-10-10 is an appropriate choice of fertilizer. The fallen leaves/needles can be raked up and disposed of. Here is a detailed discussion of fertilizers for emerald cedar hedges from one of our previous posts: https://www.torontomastergardeners.ca/askagardener/fertilizing-emerald-cedar-trees/ This post itself contains other useful links.
Good luck.