Answer #2 ·
Gardenality.com's Answer · Hi Linda,
The inner foliage shedding is normal for this time of year. My guess is that your plants could be going through some transplant shock as well. Lack of water will also cause an Arborvitae to start yellowing in the center and dropping foliage. Make sure when you water to soak the plant well. It's a good idea to set the hose at the base of the plant and allow the water to trickle for 30 minutes to an hour. This will allow for the water to soak deep down to the bottom of the root ball. Now that the cooler season is upon us the Arborvitae should not need as much water. It's best to water heavy and then let it rest. If you are getting a good rain or two each week you shouldn't need to provide any extra water. If it's drought like I would deep soak about twice a week. Soon as winter sets in you should be done with watering unless there's an extended drought period.
Make sure as well that the plant was installed correctly. The top of the root ball should be at ground level or slightly above ground level with no soil on top of the root ball. It's ok to add mulch, but no soil covering the top of the root ball. Soil on top of the root ball can cause to much water retention and lead to root rot.
Arborvitae should do fine in containers as long as there is plenty of room for the roots to grow. If the root ball takes up the entire pot, at time of planting, it will be just a matter of time and the plant will begin to decline. Plants in containers always need room for root expansion or the plant will become root bound. Once root bound, signs of stress will begin. Plants in a pot will need slow release fertilizer as well. Slow release fertilizer releases a small amount of fertilizer with each rain or watering. The best slow release fertilizer that I know of is Dynamite or Osmocote.
Hope this helps you!
Brooks Wilson)