My Emerald Green arborvitae that I planted this Spring is starting to brown out. The same thing happened to the previous Arb that I replaced because of the same reason. I treated both with a granular disulfoton 2% as suggested for sprider mites. That obviously didn't solve my problem. The pricture is of the older Arb that I replaced. Can someone advise as to what's causing the browning and what I can do to stop and prevent it? Thanks.
If it was planted this spring, it could be either transplant shock or not enough water. If you planted it and then the weather got hot before it really had time to get established, that could cause problems. And even if it got a bit established before hot weather, plants need a good amount of water during their first year so it's very possible that you didn't water it enough (especially if you had a hotter or drier than usual summer). There are probably insects and diseases that could also cause this but I don't grow arborvitae so I'm not familiar with what they're typically susceptible to, hopefully someone else will comment on the other possibilities.
For the browning that is lower on the plant, it could be a dog peeing on the plant, but I guess I would go with not enough water during the growing season since the browning extends up the side of the plant.
Is the side that's browning facing the Southwest? If so, it's probably from a lack of water during its first growing season. During the first year, most of the moisture that the tree is getting is coming from the roots in the original root ball. Very few roots will have moved out into the native soil until fall of the first year. I would water very well during its second year in the ground too.
When you water a newly planted tree or shrub, you need to make sure that you water close to the stem so you make sure that the original root ball is soaked. Most nurseries only have a one-time replacement guarantee on their trees and shrubs and many times the tree or shrub needs to be completely dead or they won't honor the guarantee. It is hard to over water an arborvitae (Thuja occidentalis) since they can grow in very damp/wet soils.
Good luck,
Mike
I think it is spider mites. You may have to use a spray miticide. It needs to be one for conifers. Spider mites are difficult to get rid of. sometimes you have to spray a few times and some miticides they develop immunity to and have to be rotated. Miticides can be very expensive. You might try spraying them off with a hose. Never worked for me.
Update FYI. Since 2007 I have planted 4 shrubs (3 arbs and 1 boxwood) in that corner and all have died. I went so far as to remove and replace all of the soil in that location thinking maybe it was overloaded with the winters' calcium chloride pellets. Last week the gas company discovered I 've had a minor leak. The gas line runs under a couple of brown lawn spots AND under the arb location! The gasman told me that when a leak initially occurs the vegetation above the leak grows great and then it begins the death cycle. I'll now see if the latest planted arb survives.
Wow, you're lucky. Not only did you find the problem with the gas ( is your bill smaller?)but you are lucky you didn't hit the pipe with your shovel. BABOOM !
You don't even have to hit with your shovel to go BABOOM!
I have a propane tank, and dh built a bed around it for me, so he wouldn't have to mow and weed eat it so much, also make the tank area look nicer. I never can get much to grow there. Even replaced the soil, nothing will grow. Finally moved everything out from around it. One thing I wondered is if the heat reflecting off the tank keeps the plants stresses so they don't grow well. Finally gave up. Right now it is filled with rocks, sedum and cilantro, some moss rose.
