White cedar (Thuja occidentalis) is one of the most common plants used to create a hedge or natural screen. It is a native plant, grown on plantations and offers an affordable green alternative to traditional fencing.
Contrary to popular belief cedars do not attract mosquitoes. Mosquitoes are naturally attracted to cool, shady, damp areas with still air and standing water, in nature this type of environment is often populated with cedars, hence the association between the two. If you remove those lowland / wetland characteristics then you also remove the factors that attract mosquitoes.
How many cedars do you need?
Generally for cedars with a height of 3’ to 6’ you would plant one cedar per foot. In the height range of 7’ to 9’ you would plant one cedar for every foot and a half and anything 10’ and above one cedar per every 2‘ or possibly more depending on how large of a height you purchase. Cedars that are very tall actually take longer to establish themselves when planted (thus will be slower to start growing) so take that into consider when deciding what height you would like to start with.
When Planting Cedars….
Cedars come with roots clumped in soil; they are not a true bare root plant (which is when no dirt is transferred with the roots). They are light weight, easy to move, but should be handled gently when transferring and planting as broken or cracked branches will brown and die. Cedars will naturally have some browning in the fall; this is to be expected and is part of the seasonal cycle of the plant and is not the same as browning caused by damage.
Scenario One: In Clay Soil (often found in new subdivisions)
- Dig a trench 12” deep and 18” wide and dispose of the clay soil.
- With a combination of good quality triple mix mixed with compost, backfill the trench a few inches, estimating the quantity of backfill so that once placed in the trench, the cedar root ball will be level with the original grade of the ground.
- Add 2lbs of bonemeal per 10 linear feet on top of the backfilled soil.
- Stand the cedars upright into the trench, arranging them as close together as possible.
- Finally backfill the remainder of the trench with the triple mix and compost combination, firmly stepping in the soil around the roots as you fill.
Scenario Two: Good Soil
- Dig trench 6” deep, turn over the soil and mix in compost using one bag of compost per 10’ of soil.
- Follow the same directions starting at step 2 in Scenario One using your existing soil.
Cedar hedging can grow up to 20’ high and 8’ wide; however with annual pruning you can control them to a minimum height of 30” tall by 2’ wide. With proper care and planting, you can expect your cedars to grow up to a foot per year, after the second year planted and your hedge will live anywhere from 30 to 60 years dependant on conditions and care.
Water your newly planted cedars well, approximately 5 minutes per 10 linear feet. During the first year continue to water your cedars once a week for the same duration, making adjustments for rain. Late in the fall, water your cedars heavily one last time to prevent winter damage and plant heaving.
When you first plant new cedars it is ideal to fertilize them 3 times, with a 2 week interval between each application, using a 12-35-12 Transplanter fertilizer. At the end of the season, around Halloween, fertilize the cedars one last time. Each spring feed your cedars with 20-20-20 water soluble fertilizer, when the frost is completely out of the ground.
Right after you plant your new cedars trim them back 25 to 30 percent of their overall height. Trimming them at this stage does not stop them from growing in height, but it does encourages the cedars to fill in thicker sooner. After the initial year, trim the hedge lightly, once annually, until the desired height is reached and then trim to maintain their size. It is better to consistently trim your hedge once each year than wait several years and do a large trim.
If you are planting your cedars in a windy area, install T-bars every 10’ on the windy side of the hedge. Thread clothesline wire through the holes in each T-bar, pulling the line as tightly as possible. Finally using natural twine, tie the cedars to the wire for added stability.
In the winter in windy locations or salt exposed areas, drape your hedge with burlap around the time of the winter holidays to protect the hedge from burning.
Example of an 8' and 4' Hedging Cedar
Hedging Cedar Root Clump