Hello. I planted 8 ft eastern cedars in my back yard in the spring and a couple trees have about 75% of their leaves turn brown. most of the brown leaves are on the bottom of the tree and the top of the tree is still green. I got a soil water meter and it indicates that the soil is wet even though I have not watered them in over a week. What can I do to get these trees to go green again? do I need to plant new ones? I do have very bad drainage in my back yard.
You do not say what type of cedars you purchased – Eastern Red Cedars (juniperus virginiana) or Eastern White Cedars (thuja occidentalis). I’m going to make the assumption that since you have planted many trees in an urban setting, you have used these as fencing or screening and therefore the more commonly used ones for this would be the latter, Eastern White Cedar.
These Cedars are known for their love of water – too much can cause the roots to rot and too little can cause severe plant stress. Both these situations can lead to browning and leaf drop.
One method of determining if sufficient water is being applied is to dig down about six inches (15 cm) to determine if the soil is moist at that level. Sometimes, moisture meters don’t reach that far down or if you are just taking one reading at each tree, you may not be getting the full picture of how wet the overall surrounding soil is.
You also do not mention how you are watering these trees. Ideally, a soaker hose at the base of the plants would deliver a targeted stream of moisture into the soil with little evaporation. New trees should be watered daily when first planted, then every second day until they are established and then cut back to every third day. How long you leave the hose running for depends on how long it takes for the soil at 6 inches depth to become moist, so you’ll need to dig and test on a regular basis until you get it right. Mulching around the base of the trees will help the soil retain moisture and also deter weed growth. Watering of these trees should continue right until freeze up as they will need all the moisture they can get to see them through the winter.
Cedars do not generally ‘break’ or put forth new growth from old wood, however I have found that it does occasionally occur if there is an adventitious bud announcing itself as a little bright green nub at that point, so take a close look.
There are a few other issues that may be contributing to lower branch damage of your trees, which may or may not be relevant but worth mentioning. Cedars are not terribly tolerant of shady areas, do not like road salt and can be damaged by animal urine, primarily dogs.
I think if you rectify your watering schedule. you may be able to save them but if they look terrible and succumb, then replacement of the dead ones will be the only option
Hope this helps.