Arborvitae Are Yellowing In Hot Weather

Question From: Colleyville, Texas, United States
Q: I planted several Arborvitae last fall and they started growing wonderfully this spring. It is now June and we have had an awfully hot spell for three weeks (mid-90's). I have the trees on a bubbler system for 15 minutes once a week. The area they are planted in is mostly well drained so I don't suspect over watering especially since we have only had one day of rain in the last three weeks. In the group I have 3 trees that are starting to turn yellow. Should I increase the number of days of watering (go from once a week to twice a week) or increase the amount of time for water (go from 15 minutes to 30 minutes)? Thanks for your help.

A: I would increase to two a week. Run the water for half and hour and check the soil around the root ball a couple of days later for moisture content. It should be kept moist. Mulching the soil with 3 to 4 inchecs of organic mulch will also help. Best And Happy Yardening, Nancy