[IrishSwede]

Every year we have a beautiful cool-season lawn (mainly turftype Fescue), we can keep it maintained throughout the entire year with little issue. However, every winter we are hit with red thread pretty hard. We usually end up having to dethatch and reseed every spring and we get a beautiful lawn until the following winter...

Our ph is good, we fertilize in late fall, we add top soil/compost every spring and aerate annually, our soil is very sandy, it is not in the shade at all....and we live in rainy Western Washington State.

My 2 questions are this
1. Should we fertilize now while the grass is slow growing (we have a mild winter and the grass never fully went dormant) as some say red thread could be from low nitrogen?
2. Should we apply a fungicide now to the lawn or will that harm the semi-dormant grass?

I would say it has taken about 20-30% of our lawn already (brown patches) and is still spreading. We also seem to be the only house in the block with the issue.

Any help or advice would be greatly appreciated!!

 

[g-man]

Welcome to the forum

To answer your questions:
1) if it is not dormant, then it can take some nitrogen. Ideally Ammonium Sulfate or Urea at not more than 0.5lb of nitrogen per 1000 sqft.
2) it there is fungus, then apply fungicide. It should not harm the grass.

Red thread normally doesnt kill the crown and the grass survives. I think it will be rare to wipe 20-30% of your lawn. Are you sure it is red thread? Could you post some images?

Some info on Red thread .

 

[GrassDaddy]

I've had red thread as well and it was freaky but some nitrogen got it out growing. Also consider mowing a bit shorter while it's wet in the spring.

 

[IrishSwede]

Thank you for the replies.

I will try and upload some pictures later today. I tested the soil and it stated the nitrogen was depleted and P and K was adequate. I think it was just a bad combo this winter with the temperatures staying around 50F and raining 6 out of 7 days a week. I just don't understand why it is only affecting my lawn and not my neighbors...well atleast the few that put the effort in to maintaining it...

I am going to try and apply some Urea based nitrogen as well as fungicide. I was just afraid it may harm the grass since it is growing so slowly and never fully went dormant. A couple years ago I applied fungicide (at the prescribed rate), and the grass never recovered in the Spring, so I am gun-shy about doing so, but a couple of years ago we made other mistakes as well that likely contributed to the desert on our lawn.

 

[Green]

What are your soil temps, and are you getting active growth? As in, are you mowing at least once every two weeks even now in the Winter? I would not put Nitrogen out unless you're getting at least some active growth. And the amount I would use would be very low because I would not want to push growth more than it wants.

Since you have 3000 square feet, spraying a low dose of fast release Nitrogen (Miracle Gro or generic urea dissolved in water) is doable. My gut feeling is that in this case, the foliar app will get into the plant better than granular. I might try 0.1-0.15 lb/thousand of N. I would not go higher than 0.2 lbs of N per thousand. If it doesn't help in two weeks, repeat. I have been experimenting with foliar Nitrogen lately (obviously not now, because it's Winter and lawns in the Northeast are dormant and the ground is mostly frozen. But in the Fall, when I had rust.) If you try this experiment, don't use a hose-end sprayer...it won't work properly with low amounts. Use a pump sprayer. And please wait until you're getting a bit of active growth if you're not yet.

When was the last time you put down N?

And please try to take some close-up photos showing the details of the fungus on the blades, if you can.

 

[thytuff1]

The key answer to this problem is to make sure that the ailment affecting the turf is indeed Red Thread. Red Thread is a fungal disease that is brought on by low fertilizer levels. Generally the affected turf will be able to grow out and over come the injury without applying a fungicide. True, a foliar application of quick release fertilizer like ammonium sulfate at a rate of 0.1 - 0.15 lbs/ K should help reverse the symptoms, and should be implemented if the proper equipment such as a pumps sprayer or other highly controlled application devise is available. However, if you are managing your lawn in a sandy soil that receives frequent rain events most likely the fertilizer in the growing system has been absorbed and metabolized by the plants, soil microbes, or leached from the system. I might suggest to go back and check what types and forms of nitrogen was applied in the fall application, and perhaps apply another application of a granular fertilizer product with combination of quick and slow release nitrogen sources. You can tell by checking the fertilizer labels. You may want to target a product that may have up to 35% quick release nitrogen forms (urea, ammonium nitrate, etc) and the rest in a slow release form. Usually depicted on the fertilizer label in %WIN (Water insoluble nitrogen. This will allow an easier application method (using a spreader) and will also keep the nitrogen stabilized in the granule for longer periods of time, allowing a gradual release. It is better if the grass is actually growing, however as long as the soil is not frozen the nitrogen that is released can be utilized by the grass plant in carbohydrate production and development of roots.

 

[IrishSwede]

The fertilizer we use most often is Milorganite, and like you said with the sandy soil we usually end up fertilizing monthly during the growing season (especially since we have a sprinkler system on the lawn) as the nitrogen seems to deplete very rapidly (the P and K seem to not drop as fast).

In the fall application which I usually do around Thanksgiving I use a synthetic granular, it does not state slow-release, but it says "feeds continuously for up to 3 months".

I applied the granular fertilizer, but am still not sure if I should apply the granular fungicide. I have both Scott's and Bayer granular fungicide as they use 2 different chemicals and I was unsure which would work better?

 

[IrishSwede]

https://ibb.co/dCWqFn
https://ibb.co/mJwqFn
https://ibb.co/i2sxvn

 

[g-man]

@IrishSwede Thanks for the pictures. That does look like red thread. The grass doesn't look like a turf type fescue. It looks like a fine fescue / creeping fescue. I'm not a fan of fine fescues. I think they should only be used in shaded areas.

Milo is a great product, but it needs bacterial activity to break it down. Moving to synthetic in late fall bridges that gap.

The bags from home Depot, lowes, Scott's ,etc; all say the same thing (last 3 months). It means they coated the fertilizer to make it not release as fast (delay). If you go to the bag and read a table it will say "#% slow released" or similar wording.

At what rate are you applying during the growing periods? Ideally you should target 0.75-1lb of nitrogen per 1000sqft per month. Since you have a sandy soil, it is best to apply every two weeks at half rate. This assures that the fertilizer is available at the root zone before it goes deeper.

I will further recommend to avoid slow release fertilizer. The delay effects means that the nitrogen will be available after it moved out of the root zone. Look at the store for the fertilizer bag with the least amount of slow %. Also you could buy fast release fertilizer (Ammonium sulfate, ammonium nitrate or urea) at a fertilizer store. It will be cheaper this way.

Lastly, the fine fescue. If you are using seeds from hd, Lowe's, etc; the bag might say: tall fescue, but it is just a marketing term. The back of the bag will have the % of seeds for each time. They might have some tttf in there, but most likely the mixed in a fine fescue and creeping red since it is an inexpensive seed that grows (looks nice at first) but it doesn't survive long term.

Could you post the active ingredient of the fungicides? I think they both will work, but one might be better.

 

[Green]

I don't doubt that you actually have red thread. It's just hard to see in the photos. It's not clear if the red tinge I see is from the fungus, or color fringing due to the way the camera lens and sensor focus the light. In any case, it doesn't look too bad at the moment.

Definitely check the percentages of quickly and slowly available Nitrogen on the bag before you buy or apply the fertilizer. These percentages will in part impact how much fertilizer you can or should be applying in this type of instance.

Honestly, it looks like the grass is ok, and will recover fine. Your goal is more to stop the disease if it's active and prevent it from being as bad in the future.

It is indeed possible there is a lot of fine fescue in the lawn; it's hard to tell from the photos. If so, it's very prone to red thread. It's just one of those things. And since that species of grass doesn't tolerate a lot of Nitrogen, you have to be careful not to apply more than it needs.

thytuff1 recommended also applying some slow release N so that your grass has a reserve supply.

 

[IrishSwede]

I think you may be right on the grass-type, we started over-seeding this past year with Perennial Rye grass as the fescue was baking in the Summer sun. I know the parts of the lawn that have not browned are where the Perennial Rye took hold the best. I think this spring I will add some top soil onto the area where the fescue is still present and try and establish some Perrenial Rye.

I really appreciate the fertilizer advice @Green and @g-man and will be adjusting my rates this growing season. I also like the idea of the half-rate (bi-weekly) as it should reduce the stress on the lawn in Summer. Out of curiosity is Milorganite fast or slow release?

Do you think that Perennial Rye is better suited for a full-sun lawn? Less issues during the rainy season? Also if it's rust or red thread should i be applying a fungicide or just waiting it out? The progression slowed a little when the rain stopped, but the rain will be back soon I have no doubt.

 

[Ridgerunner]

Out of curiosity is Milorganite fast or slow release?

It's a bit of both. 40% of the N is urea (fast release).

 

[FuzzeWuzze]

Do you think that Perennial Rye is better suited for a full-sun lawn? Less issues during the rainy season? Also if it's rust or red thread should i be applying a fungicide or just waiting it out? The progression slowed a little when the rain stopped, but the rain will be back soon I have no doubt.

Can you keep it irrigated regularly? My full Rye back yard that gets full sun that i did last year looks great.

Regardless of what you go with you should ensure you get top NTEP rated varieties against diseases that plague us here in the PNW because the ground is wet 7-8 months out of the year and theres usually a lot of clay under the top layer of soil that can make drainage a pain,, its just not a problem many other cool season grass people have to worry about.

Places like protimelawnseed here in Portland sell good mixes for our area that dont get affected by red thread and other diseases wet conditions bring. My back yard is their PHD blend (3 way rye) and still looks great.

 

[thytuff1]

@IrishSwede On the fertilizer questions: Milorganite is a wonderful product and one of my all time favorites. It is darn near idiot proof, meaning you can apply really heavy amounts and still not have any burn. It also supplies 4% iron which leads to a darker green color response. However it is an organic product which relies on microbial activity to break it down in the soil. Soil temperature is the most important factor in how fast the nitrogen is broken down by the microbes and made available to the plant. So during winter months when soil temperatures are generally lower you may not see the response as quickly as you expect. Additionally if you are applying milorganite on a monthly basis that should be plenty of nutrient supplied to the turf especially in the winter months when growth is slower. But also remember that Milo has a very low Nitrogen % component (6%) and that you would need to apply 8.3 lbs of product per 1000 sq. ft. to apply a half pound of nitrogen. Make sure to check on your application rate to make sure you are applying the correct amount.
I agree with @Green that from the photos your lawn looks okay overall and that when the weather changes it should recover and be fine. Both fine fescue and ryegrass are susceptable to the disease but in only rare cases needs to controlled by fungicides.
On the turf variety question perennial rye grass does extremely well in full sun especially if you are able to irrigate it. It will most assuredly out compete the fine fescue that may have been planted as a part of a seed mixture when the lawn was established. Especially under the fertilizer regiment that you have explained that you have implemented. Bottom line is you should double check your fertilizer rates, keep your eye on the spread of the disease and only if it gets a lot worse think about applying a granular fungicide.
One last note though: I believe that spoon feeding your lawn especially in the growing season is the way to go as you just get more control that way, however applying a high quality slow release fertilizer as a base will be very sound as it will provide a stable consistent feed. The nitrogen component will be held inside the fertilizer prill and not move out of the system via decomposition, volatilzation, or leeching. As long as you don't pour the fertilizer down the drain or apply it directly into a water body it should perform as expected. It even will release a little more slowly in fine textured soils.

 

[Green]

One other thing to add: Since PR tends to get affected by red thread as thytuff1 mentioned, finding cultivars with lower incidence or higher tolerance might be something on your checklist when figuring out what blend to use the next time. In a PR/FF lawn in an area where it rains often and a lot, I just don't see it being possible to totally escape red thread. There will probably always be little areas where it happens every so often, no matter what you do.

 

[Green]

It even will release a little more slowly in fine textured soils.

Why is that? Mechanical action jostling the particles,? Size of pore channels in the soil? Ionic interactions?

 

[IrishSwede]

Thank you all for the feedback. The mix of seeds we will be over-seeding with is a brand called JB Instant Lawn and contains mostly Stellar PR and Apple PR from Oregon....hopefully this will be a better blend than Scott's Pacific Northwest mix.

Based on the replies I have gotten, I think I will lay a slow-release down in the fall and spring and keep with a regular feeding of Milorganite in between.

As for the red thread...the only thing that got me scratching my head was that I am about the only lawn in our community who seems to get it every winter and it only affects my front (full-sun) lawn and not the back (completely shaded). I think it may just be that I usually stop fertilizing after Thanksgiving, and with my uber sandy soil, the nutrients are just washing out too fast. This next winter I will try to fertilize a couple times with a fast-release and see if it helps.

For a full-sun, sandy soil lawn should I stick with the PR or should I try and incorporate some Tall Fescue?

 

[Green]

PR is fine for full sun. Plus, it's really hard to grow Tall Fescue in existing PR lawn areas. Even when doing a new seeding on bare soil, you probably wouldn't want to use more than 5-10% PR seed by weight, if mixing with Tall Fescue. 95-5 or 90-10 would be about right. Tall Fescue is pretty resistant to red thread, though. I've hardly ever seen it affected. Maybe once.

 

[IrishSwede]

PR is fine for full sun. Plus, it's really hard to grow Tall Fescue in existing PR lawn areas. Even when doing a new seeding on bare soil, you probably wouldn't want to use more than 5-10% PR seed by weight, if mixing with Tall Fescue. 95-5 or 90-10 would be about right. Tall Fescue is pretty resistant to red thread, though. I've hardly ever seen it affected. Maybe once.

Which grows a thicker lawn in your opinion?

 

[FuzzeWuzze]

Thank you all for the feedback. The mix of seeds we will be over-seeding with is a brand called JB Instant Lawn and contains mostly Stellar PR and Apple PR from Oregon....hopefully this will be a better blend than Scott's Pacific Northwest mix.

Based on the replies I have gotten, I think I will lay a slow-release down in the fall and spring and keep with a regular feeding of Milorganite in between.

As for the red thread...the only thing that got me scratching my head was that I am about the only lawn in our community who seems to get it every winter and it only affects my front (full-sun) lawn and not the back (completely shaded). I think it may just be that I usually stop fertilizing after Thanksgiving, and with my uber sandy soil, the nutrients are just washing out too fast. This next winter I will try to fertilize a couple times with a fast-release and see if it helps.

For a full-sun, sandy soil lawn should I stick with the PR or should I try and incorporate some Tall Fescue?

Both Apple and Stellar are good seeds from MtViewSeeds here in Oregon. Way better than the shit you'll get in Scotts.
FWIW: If you have a Wilco near you, they sell MtViewSeed's Top Choice so if you like
the result of the overseed you can find more easily in future years,
since JB's blends change constantly and arent always that great.http://www.mtviewseeds.com/turf/topchoice.php

I like MtView because they have data sheets for all their varieties, so if you care

http://www.mtviewseeds.com/downloads/datasheets/ApplePDF.pdf

http://www.mtviewseeds.com/downloads/datasheets/Stellar3GL.pdf