Question
I have 5 arborvitae trees in large pots (aprrox. 2 1/2 feet wide).  They have been doing fine for the past 5 years.  They now are all getting brown and yellow underneath.  I've lost one already.  They were expensive to have been put in these pots.  What should I do?  I have been advised that it is pot rot and there is nothing I can do.  I just trimmed all the tops of them down.  Is that ok to do?

Answer
Diane,

The pots that the Arbs are planted in are causing two problems- root restriction and possibly root rot. Check the pots to make sure they are draining correctly, Arbs do not like too much water. The other problem is that there is no room for the roots to grow. Roots die off and are repaced by new ones, it is common in potted plants that after a while, there is no more room for the new root grwoth. Plants this size should not be planted in pots this small, they should be planted in a lawn area or in pots as only a temporary measure.

Ed Gulliksen