Hi, Kimberly here from landscape solutions for you. Thanks so much for your zone information. I live in zone seven also and with colder temperatures at night over the last month, this is common with the Cypress family as well as other specimens.
If you are concerned that there may be something more going on with the Lemon Thread, take a small sharp knife and scratch the surface of the trunk or branch of the Lemon Thread. If there is green the Lemon Thread is healthy and is just adjusting to colder night time temperatures. If the trunk or branch is brown it could be in shock. If it was newly planted, this could be common. If not, I believe it is the specimen adjusting to the cooler autumn temperatures.
If you feel it is more than the colder temperatures or newly planted shock, I would recommend to bring a smaller branch to a local nursery if possible and see what they think. I hope this information helps you determine the brown on the bottom. I went through the same thing the first time I planted different species of the Cypress family. The Arborvitae and Cryptomeria family will tend to do the same thing when cooler temperatures move in.
Thanks again for asking the question here at landscape solutions for you and feel free to ask anytime. Have a great evening.
Kimberly
Nov 03, 2009
additional info by: Anonymous
As to the original question, let me add that I live in zone 7, and the browning began only recently, as of September.
Nov 03, 2009
Lemon Thread Cypress by: Kimberly
Hi, this is Kimberly from landscape solutions for you. Thank you for asking the question on your Lemon Thread Cypress. I am not sure what climate you live in. If you live in a cooler climate the Cypress family can have this problem, especially after some cold weather. It isn't uncommon for the Lemon Thread to have parts of the lower needle leaves to turn brown when the weather turns colder. If you live in a warm climate where the temperatures remain warm, the leaves turning brown could be too much water or lack of water. Let us know what climate you are in and we can go from there.
Thanks for asking the question here at landscape solutions for you. Feel free to ask anytime and hope your day is going great.
Kim