# Wintergreen Boxwood Disease



## Mocajoe (Apr 9, 2018)

Trimmed 5 Boxwoods today that are planted under a Pink Flowering Dogwood. Several of these have some brown die back spots. Any thoughts on what may be causing this? The Dogwood has suffered from Anthracnose disease for several years and has been treated with Propiconazole in years past and pruned as needed to remove diseased branches. I have 4 more Boxwoods that are under a Japanese Maple that appear to be disease free. Could the Anthracnose in the Dogwood be causing the problem in the Boxwoods? Treatment thoughts?


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## greencare (Sep 14, 2019)

Did you fertilize in early spring? I try to fertilize again after trimming in late spring. Also, you should mulch those boxwoods; rain splatter spreads diseases.


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## Mocajoe (Apr 9, 2018)

greencare said:


> Did you fertilize in early spring? I try to fertilize again after trimming in late spring. Also, you should mulch those boxwoods; rain splatter spreads diseases.


Yes, they were fertilized in April with 20-0-8. All of the landscape beds are mulched with double ground hardwood.


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## greencare (Sep 14, 2019)

How about watering? Overwatering can also lead to fungus problems.


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## 440mag (Jan 29, 2018)

Phyton 27

https://store.phytoncorp.com/phyton-27

https://www.amazon.com/Phyton-Oz-Systemic-Bactericide-Fungicide/dp/B00VKPL8FU

(Phyton 35 is the real deal but, it is quite expensive (moreso than the Phyton 27, fer sure!) Alas, we have a Jap Maple specimen that warrants the 35 though ....)

Best o' Success (beautiful yard, btw! :thumbup: ) !!!


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## Ortho-Doc (Feb 3, 2019)

Mine had spider mites that looked like this. Shake the branches with a white piece of paper beneath it then smear your hand over the paper. If you see brown streaks or little red dots moving you have spider mites.


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## greencare (Sep 14, 2019)

Ortho-Doc said:


> Mine had spider mites that looked like this. Shake the branches with a white piece of paper beneath it then smear your hand over the paper. If you see brown streaks or little red dots moving you have spider mites.


Spider mites are a real pain. I think one can only manage their population with bug spray, but I am finding that they just don't like leaves to move in the wind. I deal with some house plants getting spider mites, and I would use a cloth duster to get rid of the webbing at the top, which is usually a daily process. This usually keeps them from killing the plant when indoors. But I have noticed that once these plants go outside for the spring, spider mites stop attacking the plant altogether. Wind and having the leaves move with the wind is your best weapon against spider mites. I also have spider mites in the boxwood and the best weapon is fertilization and allowing the boxwoods to grow leaves in the summer so they don't remain static.


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## Mocajoe (Apr 9, 2018)

440mag said:



> Phyton 27
> 
> https://store.phytoncorp.com/phyton-27
> 
> ...


Thanks, 440mag. If I decide to go the chemical route, I will look at putting Phyton in the mix. Tried for the last 4 years to deal with Red Thread in the lawn and Anthracnose in the Dogwoods with Propiconazole and Azoxystrobin. Each year the problems comes back. I am moving toward a more cultural approach, bagging the grass, dethatching, tree pruning. The Red Thread goes away when the temperatures rise and the grass always recovers. The Dogwoods seem to be improving this year with more fertilization. Hopefully the Boxwoods will recover, if not I will move on to plan B.


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## Mocajoe (Apr 9, 2018)

Ortho-Doc said:


> Mine had spider mites that looked like this. Shake the branches with a white piece of paper beneath it then smear your hand over the paper. If you see brown streaks or little red dots moving you have spider mites.


Thanks for the insight on spider mites. Tough to deal with a problem you can't see. I just went outside and tried the paper test. No signs of mites. One more variable eliminated.


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## greencare (Sep 14, 2019)

Mocajoe said:


> Ortho-Doc said:
> 
> 
> > Mine had spider mites that looked like this. Shake the branches with a white piece of paper beneath it then smear your hand over the paper. If you see brown streaks or little red dots moving you have spider mites.
> ...


Do the leaves look like this?









http://oregonstate.edu/dept/nurspest/boxwood_spider_mite.htm


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## Mocajoe (Apr 9, 2018)

greencare said:


> Mocajoe said:
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> > Ortho-Doc said:
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They do not. Here is a closeup of a damaged section.


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## HoosierLawnGnome (Sep 28, 2017)

Dd you get frost or a freeze like we did in Indy?

This is what freeze damage to new growth looks like


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## greencare (Sep 14, 2019)

Mocajoe said:


> greencare said:
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> > Mocajoe said:
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Those spots looks very similar to 'boxwood blight'. I had couple of these spots develop last year, then I immediately fertilized and stopped watering, even though it was September I believe. Boxwoods seem to be recovering from it. The spots developed after I started watering the boxwoods everyday in the summer, which I have never done before, let alone any watering because they are mostly in a shaded area.


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## Mocajoe (Apr 9, 2018)

HoosierLawnGnome said:


> Dd you get frost or a freeze like we did in Indy?
> 
> This is what freeze damage to new growth looks like


We did get a frost in mid May, very atypical for St. Louis. The Boxwood damage was visible coming out of winter in early March. Our winter was not unusually harsh, these shrubs are 20 years old and have gone through much colder winters. The Boxwoods that I trimmed actually looked better from a disease standpoint before trimming as new growth was masking the brown areas. I took off about a half inch of new growth to get the desired shape I have been working to develop over many years. Hopefully they will grow out of this. Thanks for your thoughts.


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## Mocajoe (Apr 9, 2018)

greencare said:


> Mocajoe said:
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Well, what ever this problem is, if over watering is the cause, I am in trouble. It is forecasted to rain here for the next 6 days🙄


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## greencare (Sep 14, 2019)

Mocajoe said:


> greencare said:
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> > Mocajoe said:
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Fertilize with 10-10-10 and let new growth fill in faster.


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## RCUK (Jul 16, 2018)

Looks like box blight. Cut away with sharp shears all the brown fungus materials whilst avoiding the healthy areas to prevent more spread. Won't look pretty but better to remove it. Also don't let the dead material fall to the ground, cover the ground with sheets or cardboard before trimming and dispose of the brown leaf material.

Clean the shears before cutting another box plant. I keep a bucket of water to dip my shears into and empty it each time I cut the next box.

There are chemicals available that can help, don't know what is available in the US as I'm in the UK.


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## Mocajoe (Apr 9, 2018)

Thanks for the reply RCUK. I believe your are correct on Boxwood Blight. Sounds like a good plan to prune out the diseased areas, will work on that later this week. I have a sprinkler head that I also need to adjust that is spraying these Boxwoods when watering the grass. Have you seen any Boxwoods completely recover from Boxwood Blight?


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## greencare (Sep 14, 2019)

Like I said before, fertilize and reduce watering. And trying putting new mulch down. Rain water splattering can spread the disease. I saw some of these white spots develop in our boxwoods last year before leaves turned brown, and as I have said before, I took immediate action by fertilizing and reducing/halting watering. But ours is in a mostly shady region, though. Some spotted leaves are just now this year turning brown, but new growth have filled in. I haven't trimmed yet, but plan to fertilize again after trimming. You have to push new growth in.

Fertilizing and reducing watering seems to be helpful with all fungal diseases in plants.


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## Mocajoe (Apr 9, 2018)

Just a follow up on the recovery and health of my Boxwoods. New growth is filling in nicely. Was not able to remove the fungus damaged sections by pruning as well over 50% of the shrubs were infected. Used a small leaf rake over several weeks to remove as much diseased material as possible. Applied one application of Humic DG and 20-0-8 fertilizer in May when I fertilized the lawn. Looks like a positive outcome.


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## Pologuy (Aug 3, 2019)

Mocajoe said:


> Just a follow up on the recovery and health of my Boxwoods. New growth is filling in nicely. Was not able to remove the fungus damaged sections by pruning as well over 50% of the shrubs were infected. Used a small leaf rake over several weeks to remove as much diseased material as possible. Applied one application of Humic DG and 20-0-8 fertilizer in May when I fertilized the lawn. Looks like a positive outcome.


Silly question. I have a ton of box woods. I recently sprayed with K4l extreme blend. How did you fertilize your boxwoods? Where did you apply the fertilizer, to the base? Should I pull back the mulch?

It appears 10 of my fully grown green velvets have sunk after 3-4 years. Thinking about pulling them out and replanting.


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## Mocajoe (Apr 9, 2018)

I use a Scott's Handheld spreader for my lawn and shrubs. The handheld works well in tight spaces where a push spreader will not go. When I fertilize the lawn, I broadcast into the the landscape beds on top of the mulch as close to the base of the shrub as possible. My Boxwoods and Dogwood Trees have responded well to the Humic DG and Hyrbrix 20-0-8. No need to disturb the mulch. Not a silly question at all.


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