Cedar hedges are susceptible to many environmental elements that can cause damage to the hedge. Once a hedge has been planted, it may take time to tell whether or not the tree was planted correctly or will take root and survive. If your cedar hedge begins to turn brown or is smaller than other hedges around it, these tips may help save your tree.
Monitor the tree daily if it appears to be stunted in growth. Check to see if it is growing at the same rate as other cedar hedges, if they were planted together.
Look under hedge, at the base. If the roots are showing, the exposure will dry out and kill the tree. Cedar hedges are shallow root trees so they tend to become exposed over time and with erosion. Apply a thin layer of mulch if this is the case, as mulch is less likely to erode.
Uncover a thin layer of soil at the base of the tree to see if the soil how the roots are faring. If they appear to be too wet, then water them less. Over-watered roots will suffocate from lack of oxygen to the soil. They will become black and moldy.
Check to see if the twine that tied the root ball is still in tact. Sometimes it doesn't get removed entirely and it can stunt the growth.
Apply fertilizer minimally. Too much fertilizer will cause root burn and kill the tree.
Spray herbicide far enough away from the hedge that it doesn't run into the root system. Herbicide runoff will kill a hedge slowly. It can take up to a year.
Look for a fungus called phytophthora root rot. This occurs when a hedge is planted in an area with poor drainage. It appears as yellow then brown leaves that wilt and fall off quickly. Plant hedges in well-drained areas or with drainage systems in place to avoid this. If your hedge develops fungus, remove the infected areas as soon as possible.
Watch for yellow spots on the grass or foliage at the base of the tree. This means an animal is urinating on the tree frequently enough to kill the grass.
Look at the tree with a magnifying glass if you suspect mite damage. Mites will eat at the tree and cause the foliage to turn yellow and brown during the summer. A miticide will clear up this problem.
Observe the twigs and branches of the hedge. If they have small notches in them, root weevils are most likely the cause. They eat the wood and cause the leaves to turn brown. Place a rubber band around the trunk of the tree to prevent the larvae from spreading.
Check to see if there are tiny white, round scales on the branches. These are juniper scales. They eat the needles and twigs. An infestation will eventually turn the leaves yellow and the tree can die. A pesticide applied in June will clear this up.