Have you had a dry, windy year? Try fertilizing it this winter, and then again in the spring. The browning in the center is pretty normal, but when it goes on the outside of the plant, that's usually not a good sign. (sorry)

Why fertilize in winter when plant is dormant? Certainly don't fertilize this fall, or the shrubs will put out tender growth which will not stand up to cold winter winter and temps.

Check the soil- well and deeply. Check drainage. If it is dry give all the plants a couple of good deep waterings before frost

Interior browning is normal and can be unsightly for a while.You'll learn to ignore it. Or take a wisk broom or wear a heavy long glove and shirt and get in there brush vigorously.

I'm sure others will have more specific ideas. But the last thing one should do to plants that are stressed is apply fertilizer.

I always thought arbs did a little spot browning about the same time the deciduous trees started to color up and drop their leaves in the fall - at least until they got a little age on them. Buds should still be there to put out clean growth in the spring. The interior browning close to the trunk seems to be a pretty normal happening. That still occurs on my older specimens and I just reach in and shake it out to let more light reach the interior; and they don't seem to be any worse for wear for doing that. I never fertilize shrubbery.

Any real dead patches that don't regenerate could also be indicative of an insect pest (spider mites?) or something environmental.

The browning may be caused by spider mites, It's usually an environmental factor that affects a plant before insects or disease gets to the plant.

Lol. I work for a nursery, and fertilizing is our answer for everything. I meant to say fertilize this FALL, not winter, but other than that, if you use a non-hot fertilizer, it works. I couldn't imagine not fertilizing every bit of my shrubs, trees, flowers, etc. It's part of my fall routine.

But the last thing one should do to plants that are stressed is apply fertilizer.

WHAT? I'm sorry, we're going to disagree here. I'm talking a low 6-3-0-3 mix (this is off the top of my head)

Try Fertilome Multiplex. It's a liquid fertilizer that you put on and drench with water. It's better than any fertilizer I've ever used. I've had customer after customer say it's revived trees, shrubs, etc. out of the problems they were having. As long as you apply it right, it's a miracle cure.

I've never heard someone say don't apply fertilizer to stressed out plants!

Points well taken. I should have written something like "check for environmental and insect problems before using fertilizer." You are not an amateur, but it is my impression (if not from this website) that inexperienced gardeners often reach for the fertilizer when, for instance, a plant develops "spots" or doesn't look "healthy." I did not know your background and I assume you'd be using something like regular strenght Miracle Grow (or even twice recommended strenght if the plant looks "sick" or common plant fertilizer with a high middle number.
No sarcasm intended, but have you really not encountered "throw some fertilizer at it" mentality?

My last observation doesn't pertain directly to your post, but all of us who grow plants- from the community garden plot to agribusiness- share responsibility for our water supplies and fertilizer runoff. I believe education of the small plot gardener is a step towards an individual's and community's awaress of the global risks of improper and excessive use of fertilizers

I hope my meaning and intentions are clearer now. Thanks.

So how do I check for these spider mites? I assume since they are mites they are microscopic. How do I confirm that is what it is and what do I do about it? Thanks for all the responses so far and I told my husband to fertilize after the first response and then got the other ones and told him to forget what I said and not fertilize and he said "too late" so they have been fertilized and I have been watering the heck out of them since I do have to admit I didn't water well this summer. Thanks blollar for the tip on the brand. I will look for that.. Is it just for evergreen shrubs or what other kinds of plants can it be used on? Thanks again all.....

I researched and I am sure that is what we have.. I saw 3 different solutions and want to run them by you all.. First use a stream of water to rinse them off but they come back.... second.. some kind of soap solution.. and third an oil stuff.. Now I am wondering if there is a more permanant solution to this problem say maybe some kind of fertilizer something that I can feed them to make them undesirable to these darn spider mites.. I believe the mystery is solved as to what happens to my hydrenga every year also. The damage description sounds exactly like what they do every year and I went out and did the test on them also and guess what.. SPIDER MITES!!!!.. So I have a big job on my hands and need more advise on what it is exactly I can do that would be the best.. If it is one of those solutions of soap or oil how do I make it and with what? Will the damage repair itself on the Arbs or are the brown spots permanant? Again... thanks for being here

I've heard through the grapevine that neem oil is the one way to attack mites on arborvitae, but have never tried it. There are quite a few applications out there, but I would suggest looking it up before applying. Kimbra, your statement that you admit you didn't water a whole lot this summer could be the answer, too. To check for spider mites, you take a white piece of paper and shake a limb over it. If you see movement on the paper, bam, you've got the nasty little critters. The problem is, most damage from spider mite shows up the NEXT year, so I'm going to assume it might be a little late to see if you have them. No worries, though, it doesn't sound like your arborvitae is going down, just going through a little stress. The damage you see will repair itself. Plants are hardy!
As for the fertilizer, I understand exactly where you are coming from idabeam. The fertilizer we use is actually environmentaly safer than all others that I've seen on the market. My dog could actually lick the bottle after applying, and I wouldn't worry about her. I did some research on the fertilome, and couldn't find much about it. I went to fertilome's website, and they don't sell it there, which is interesting to me. I'll talk to my boss about it.

shrubs.. planted in mother earth ...NEVER NEED FERTILIZER,,,

NOR DO TREES...

NOR DO CONIFERS ...

perform a professional soil test ... if it indicates anything is lacking then take action... otherwise save your money on fert ...

the nursery biz is a whole other industry .. and potted stock MIGHT need fert .... but that has NOTHING to do with stock in the ground ...

internal browning IS NORMAL for all conifers ... ergo .. there is no need to do anything ...

if you fertilize your lawn.. all trees.conifers/shrubs.. will get what they need ...

and never rely on information that begins: 'I've heard through the grapevine' ... its a good place to start your research ... but not factual enough to act upon ...

interior browning is increased due to drought... improper watering the second or third year.. [meaning not 'fully-established plants'] .... and by transplant ..

ITS NORMAL >> JUST KEEP THEM PROPERLY WATERED... and that means proper water at the root zone.. not a little spray on the soil surface ... dig hole to find out if there is any moisture down 3 to 6 inches ...

good luck

ken

PS: arbs are conifers.. not shrubs ....

So Ken..you didn't touch on the subject of the mites... what are your thoughts on the spider mites contributing to the exterior brown spots and what in your opinion would you do about them? As far as the watering.. I know I screwed up and have taken steps to amend this.. I bought a soaker hose and left it run all day yesterday and will do the same tomorrow..

if they live through the winter ...

we will worry about the mites.. IF ANY .. next year ...

they will all be dead with the first frost.. which for me.. was last week .. do NOT consider any chemicals at this time ...

other than shear speculation ... do you have any proof that mites are an issue???? i have to admit that i am rather sick.. and havent read all the posts ...

healthy conifers can withstand many a mini plague .. its stressed plants that suffer the worst ... un-stress your plants... and you should be all set .. and it sounds like you are on the right track ...

there is much info on how to deal with spider mites on picea glauca conica.. aka dwarf alberta spruce... that involves spraying them off with the hose ... yes.. simply spray down the plants every now and then ... as hard as possible. without damage ... and you can reduce or remove the population ...

how about some pix??

ken

PS: its not uncommon for shipping damage to show up when interior browning occurs .... some punk whipping your plants around by the foliage .. on and off trucks..... across the parking lot.. etc ....

Yikes... I'm new here and have never posted pics... I am needing help with how to do that.. I did the paper test and yes I saw the little bas---ds... I looked for internet sites about them and the descriptions and photos I saw really matched what is going on.. We have 6 that have been here for 4 years and looked great till this year.. We planted 6 more this year and when we planted them I noticed the insides were very brown and I pulled out hand fulls and hand fulls of dead needles or leaves or whatever they are called on an arb.. Now in the last couple weeks we have been seeing brown spots on the outside of all of them.. I am worried about losing all of them since it would be quite expensive to replace them .. they are all 6 foot tall.. Hope you feel better..