browning on Blue Chip Junipers

Richland, WA

I've sprayed them with Kop-r Spray and Lilly Miller Microcop Fungicide (with Stay-Stuk M) a few times a year, plus with Spinosad and Iminicloprid spring and summer (they get webbing and I've seen a few red mites, but have seen no other insect, though I've read they can get a web worm) . They're watered with one 1/2 gallon emmitter every 5 days in summer, about every 3 days when above 90 degrees. They still get browning in late summer, especially those with more shade. Most is near the end of branches but other places too. So I'm looking for suggestions--I thought I did'nt over water, which I know is a common problem. We're having a hot summer, around 95 most of July and August so far. I've had several die in the past so I started the spraying. Less browning but its still there. This is Richland, WA--Sunset zone 3B, I think usda zone 6, .

Rolesville, NC(Zone 7b)

A picture or two would help us help you :)

Ayrshire Scotland, United Kingdom

I agree that a picture would be best way of trying to help find the problem as there are as many reasons for browning at the tips or elsewhere as there are hot dinners.

Also even though you are watering what you think are plenty amounts, it doesn't mean the water is actually reaching the roots under the soil especially in hot weather there is a caked hard skin forms on the soil and water runs off this crust missing the deep roots way down.
I always sink a clear juice container into the soil when I plant shrubs / trees, remove the bottom and cap, sink the container into the soil close to the root area, about 1 1/2
feet away from the trunk, when you water, you fill the containers up a few times and this allows the water to reach the roots where it's most required, it also helps with some shrubs that need feeding, a liquid type feed can be given at watering time, you can leave these containers in place for a few years till you know the tree's / shrubs are able to fend for themselves.
Send out a picture for further help.
Best Regards. WeeNel.

Contra Costa County, CA(Zone 9b)

I also would be concerned that the drip system may not be applying enough water.

Take a freshly sharpened new pencil.
Plunge it into the soil the day after the drip system has run. With established plants you should be able to stick the pencil all the way down into the soil and bring it up dark. The freshly sharpened wood will be dark if the soil it wet.
Try it a few days later. Try it at different locations, and at different depths.

1/2 gallon per hour for each plant? I would probably run the system for about 10 hours in my heavy soil. Then let it go a week to 2 weeks depending on the temperature. The goal is to get the water down deep so it cannot evaporate quickly. In soil with high clay content this takes a lot of water applied slowly.
In sandier soils you might run it for 4-5 hours, but much more often. Sandy soil accepts water easily, but does not hold it. The plants will use up whatever stays in their area very quickly.

Each area has its own list of pests and diseases, so if you are following the instructions of a reputable adviser, and it is not working, then return and ask again. Perhaps there is some different problem, or perhaps you are not applying what that person said correctly. Reputable plant people might be certified nursery people, agriculture advisers, department of agriculture, a local university with a good horticulture program or extension service.

Ayrshire Scotland, United Kingdom

I am not familiar with all the products your using on the plants BUT, to my mind, it is over use, either stick to the one product or the other as sometimes different products can have serious reactions when used along side others even IT there are intervals in between.

For RED Spider Mites it is proved that keeping up a fine misting is a way to control these (not kill them) the wet from the misting under and on top of leaves prevents the mites from reproduction as they cant survive in damp humid conditions, they thrive on hot dry atmospheres and can destroy some plants within a month, but these are mostly soft tissue leaves that die off first.

I'm not an expert on Spider Mites by any manner of means but IF you can see the mites by your naked eye then I would agree you have a problem with them BUT, these mites are so small, (I have to use a magnifying glass to find them if I suspect they are present, but these will be many different types of spider mites but all need dry hor places to multiply at the rate of knot's.

Hope there is another reason for the leaf browning as that would be easier to control.

I agree with Diana K and her suggestion for testing the water reaching the roots of the plant, great idea about sticking a pencil into the soil and seeing IF the wood alters in colour, I use a finger as if the soil is dry a few inches down it is a good bet to say the soil is bone dry way down at the roots but a pencil would go deeper into the soil as would a wooden skewer we use for food , just make sure the wood is clean and you will then notice the different colour if it gets wet, a bit like checking a sponge cake to make sure it's cooked right in the middle, Jeeeeeez were now onto cooking LOL. Take good care.
Kindest Regards. WeeNel.

Richland, WA

Thank you for all the thoughtful advice. I try to get advice from the local "Master Gardeners" operated by the county and University--mostly volunteers. Half the time they lose my samples or tell me what I already know, or if I'm lucky, the manager walks by their desk or comes into the office, and they hand it to her and she makes a diagnosis and suggestions. I'm quite sure I've already tried them with this problem. But maybe I should try again.

So I decided to just try a lot of things I've read about (I have seen red spider mites, there are webs within the plants), so Ive used Spinosad, and "Bayer Advanced Insect Disease & Mite Control" (Iminacloprid), weeks to months apart, because they list mites and web worms on Junipers, and other bugs and diseases. And I use fungicides because I've read Junipers are susceptible to fungus and treating frequently is necessary, because they can't be killed, they can only be prevented. I've also heard over and over that most of them die from over watering, so I haven't thought that's the problem for me. But it has been an especially warm summer, so maybe dryness could be becoming a problem.

So I will try the pencil test. I discovered when I went out to take the pictures that I have 1 gallon emitters (not half gallon) some places, so now I need to check all of them (about 20). It's hard in these prickly plants and somewhat prickly wood chip mulch, but unavoidable it seems now. The soil is loamy medium porous. I use a drip system so I wouldn't think I need an underground water container?
Didn't think they need feeding either, but maybe I should look into that. The zone is 6A-7BThe spinosad bottle states "use of a nonionic spray adjuvant at 0.1% v/v helps". Do any of you know what that is?

(I think the brown tips I formerly wrote about are just where they had gotten buried. The pictures show the brown branches within the plants).

WeeNel, is Argyl castle in Ayrshire? Then I think I have been in your bonny area, 1969 (a bit ago). We don't hear much about sponge cake here. What do you use it for? But I'm making two Blueberry pies tomorrow. It least I don't need advice about that--cooking hurray!!
Diana--I moved here from Berkeley CA 1996. Didn't know Contra Costa had heavy soil. Don't remember Berkeley's.
About NC----I know nothing!!
Thanks again.

Thumbnail by raiseabed Thumbnail by raiseabed
Ayrshire Scotland, United Kingdom

Are the Brown tips you have found on NEW formed foliage, this foliage is normally a brighter green than the older foliage, anyway IF the tip of the branches are as I've described, then I suspect the brown tips are the casements of the new leaf and they will fall off exposing the new fresh growth.

The mites you see are NOT red spider mites and that's just a guess on my part, Red spider mites are so small that they are very difficult to spot by the naked eye, were talking about smaller than a pin head. What the Junipers are prone to have is, The caterpillars of the Webber Moth that make webs and they spin the foliage together, I suspect that is more likely what you have when you find webs on the INSIDE of the branches, whereas Spider mites like to have webs on the outer more tender leaves, that's where there is more heat and the webs of the Mites are a silky as anything, you know you have spider mites when you find the fine webs and a magnifying glass is then required to find the mites running around the fine webs from one leaf to the next.

Another thing Junipers CAN have is Scale insects infestation, you spot them by the crusted Galls sticking to the leaves like little crusts.

Another thing is RUST, that is caused by fungus and there are several fungus*s that could cause rust, you will know you have it by finding orange-yellow pores and normally around April-may time

I have to also tell you that because a plant CAN have lot's of different diseases, insect problems or whatever, it sure never means that the plant you are growing has, or will have any of those mentioned, what it is saying is, IF you have problems showing up, these are the more common things to look out for, NOT telling that's what you do have.

Hope this helps you try understand a bit more and you can maybe relax a bit, not go looking for sprays or insect repel you don't really need as there is such a thing as over kill when it comes to fungicides etc.

Best Regards.

Rolesville, NC(Zone 7b)

That looks like the typical "summer yuck" that spreading junipers develop here. It's not really a disease are fungus, it's just a lack of air circulation. Have you had a particularly humid summer?

Ayrshire Scotland, United Kingdom

Hi Raiseabed, NO Ayrshire where I live is NOT in Argyle BUT, we are neighbours, here in Scotland way back in history when there was a feudal system (that is when a king gifted lands to an Earl, Lord or some titled person, the gifted land was given the name of the knight (sir) Lord, Earl, Duke or whoever, so Argyle was so called after the Duke of Argyle and that land will remain Argyle there after. My area of Ayrshire is part of the land of Strathclyde which in turn forms part of other lands Brisbain, as in Brisbain in Australia, our land owner was also granted lands out in Australia so it gets quite complicated however, these landed families own hundreds upon hundreds of acres and most are classed as sleeping owners, (they dont live, on the land or do anything to improve the land) NOT sure IF you ever heard of the Highland clearances where all the peasants were thrown out of the land owners cottages because the owners has to start paying a tax on each property so the peasants (farm workers were starve out and moved to America by boat, Canada, Australia, so the feudal system could be quite brutal, thankfully we dont really have that system any more but IN LAW, the old rules COULD be applied.
Argyle is beautiful and depending where you were staying when here, you may have came into Ayrshire. which is also lovely in nice weather ha, ha, ha.
Take good care and hope your tree recovers soon.
Best Regards, WeeNel.

Contra Costa County, CA(Zone 9b)

There are many soil types in CoCoCo, depending on where you are.
Most of my clients are in the 680 and 24 corridors, and these areas are alluvial from when the central valley was a sea, and before Mount Diablo started shoving its way up into the air.
Basically most of the soils I deal with are high clay content.
Many parts of Berkeley are up in the hills, and the soil is decomposed rock, and not very deep. Lower down, near the bay the soil is a bit deeper. (The soil that washed down from the hills almost as fast as it formed)
There is even a fair amount of sandy soil out near Brentwood and Oakley, though that is variable. It is not unknown for one lot to have both clay soil and sandy soil. I do not do a lot of landscape work out that way, though.

Anyway, back to the Juniper:
In California:
Many juniper also get various species of twig girdlers. The female (a moth) of these caterpillars lays eggs just under the bark and the juvenile eats its way around the branch, cutting off the water flow in both directions. There is one main species here (Periploca nigra). I would not be surprised if certain beetles might do the same or similar damage (I know they can do similar damage to pines and other conifers).
The symptom is that the branch from where it got girdled on out will be brown, dry, but it will be quite healthy deeper into the plant. The part where the bug ate might or might not be any weaker. If you see a spot like this, cut off the brown part and some of the green part. Then peel off the bark very carefully, see if you can see where a small bug has eaten its way around the stem.
Bt not will control this, since the female does not eat the juniper, and the baby only eats the inside, under the bark. It takes the stronger, more persistent insecticides to kill the female when she comes to lay the eggs. Usually in the spring.

I have heard about the Master Gardener program, and I seem to have the same experience you have had: Some people know what they are doing, others do not. Maybe you could call to find out when the manager or one of the more experienced people might be in. Or address the sample to that person, carry it in and ask that it be placed on that person's desk or mail box.

Are there any Department of Agriculture offices near you? I have found them more useful than the Master Gardeners.

Juniper are fairly closely related to Cypress, and several pests that are found on Cypress are also found on Juniper.

Contra Costa County, CA(Zone 9b)

In those photos it looks more like the older growth is brown, and the new growth is coming out pretty nice.

Drip emitters are not very accurate. No matter what brand, what style. It does not matter very much if you have half gallon or one gallon emitters, or a mix. You might be getting as little as 50% of rating, or double. So your 'half gallon' might really be putting out more water than the 'one gallon'.

I would test the patch of junipers in several areas and see how moist it is before you water, and how deep down, then water as thoroughly as you think is good. Then go out the next day and test again, in several locations, several depths.

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