My daughter and her dog lives with us at the present time. Unfortunately, my daughter has allowed her male dog to pee quite often on our cedar bushes. A lot of the leaves have turned black. Is there is a solution I can spray on the bushes to repair this? If we make sure the dog stops peeing on the bushes, will they return to health?
Dog urine will turn the foliage of lower branches yellow, then dark brown or black. Cedars are especially susceptible to this type of damage. Salts in the urine burn the foliage causing it to appear scorched. These black branches will not return to health. Trim them back to the point that the foliage is still green. Going forward, if you can, water the peed-on area immediately as this can help dilute the urine and minimize plant damage.
For further information on what you can do to combat the effects of dog urine on your cedars you may wish to read an earlier post to a similar question:
“The issue of dog urine dotted along the hedge pathway is a concern because the urine has a high nitrogen content (so the result is similar to if you have over-fertilized the area). One strategy is to water plants within a few hours of the doggy visits, to dilute the urine effect, although this would take time. Perhaps a thorough watering on a regular basis would do the trick. Also, as dogs don’t like getting wet, installing a motion-activated sprinkler might be a good deterrent. Here’s a Q&A that discusses some strategies, Dog-friendly plants. Another consideration is to use good rich soil that contains organic matter (e.g., compost). This will support healthy microorganisms and can help buffer urine (making it less harmful to the plants). Remember too that sometimes dogs mark territory by leaving very small volumes of urine behind; these small releases are less likely to harm the hedges than cases where the dogs release significant amounts of urine near the hedges”.