Lawn Disease

Red Threads on the Green!

Welcome back to the Wonderful World Baseball_(crop).jpgof Weed Man!   This week we will be wrapping up our lawn disease series.  If you have run into lawn diseases this is a great resource to help identify and rectify what may be going on in your lawn.  This final week, we are going to talk about Red Thread on the Green – unfortunately I’m not talking about baseball.  We  are going to uncover the details about the lawn disease Red Thread.

Red thread is a disease that shows up in lawns that are cut at a taller height during cooler times of the year such as spring or fall.  Although it is not what you want to see in your lawn, it is not life threatening to the grass plant.  Red thread will generally only affect the blades of the grass plant – roots and crowns are not red-threadinfected by the disease which means the plant can eventually overcome the disease.  In rare cases, the disease can get out of control or is a very severe case, the plant can die.

This lawn disease will typically develop, as mentioned before, during cooler parts of the year.  Usually when temperatures are in the 40-70-degree range, and when there is a higher moisture level present on the lawn.  Although rare, healthy lawns can get this disease as well.  However, red thread will show up most often on lawns that have been poorly maintained.  Red thread, like many other fungal diseases, can be spread on the lawn by foot traffic or lawn equipment.

Small spots will begin to appear on your lawn – they can begin as straw colored, light pink, or reddish patches.  They will be about the size of a silver dollar but can grow to be anywhere from 4” to 2’ in diameter.  Red Thred thread 2.jpgread is most easily identified in its later stages when you can see red threadlike hairs or strings attached to the grass.  There are other lawn diseases that will look similar, such as dollar spot, pink snow mold, or pink patch.  Pink patch is probably the most commonly mistaken, as they are similar in color and appearance.  However Pink patch looks like the grass has cotton candy on it, vs red thread has pink or read threads on it.

So, what do you do when you discover this strange disease on your lawn?  Once discovered in your lawn, there are some easy steps to clear up the disease:

  • Implement recommended watering habits – deep and infrequently
  • Keep a high mowing height to promote a healthier root system that can withstand disease better
  • Reduce the amount of shade by trimming trees and shrubs that contribute to the shady areas
  • Increase the air circulation by thinning trees and shrubs or making appropriate changes to landscaping to promote air flow in area affected
  • Provide a light application of fertilizer to help promote recovery
  • Reduce thatch with core aeration
  • There are fungicides that can be applied to help recover, however they can be very cost prohibitive to do.

Although there are chemicals that can help control fungus in the lawn, we generally do not recommend it.  There is a time and place for use of chemical treatment, but too often homeowners just want a quick fix.  Many times, chemical control for fungus treats the symptoms and not the underlying cause.  Chemical control can get very expensive as it needs applied consistently and often to work.  If you make the necessary changes to your cultural practices it will improve on its own.

If you are seeing red thread, or any other lawn disease in your lawn, and need some help with it, don’t hesitate to call the Weed Man! 208-888-9911 #wecareforyourlawn




This week at the Wonderful World of Weed Man we will be continuing on our “Your Lawn May Have the Sniffles!” lawn disease series.  Last week we talked about powdery mildew.  It is common this time of year, so if you are seeing it, check out that article to see how best to treat it.  Today, we are going to focus on fighting blight!

As lawn fungus goes, blight can be a catchall term for many variations of leaf blight.  We see a few of the variations every year.  Particularly Pythium Leaf Blight as well as Ascochyta Leaf Blight.  I know, I know, that is a mouthful.  For today’s purposes we are going to discuss Ascochyta Leaf Blight.  If you are interested in Pythium Leaf Blight, we have a great resource on our website about it.

We tend to see Ascochyta Leaf Blight most often in the beginning of summer when temps spike, or at tail end of the summer when it cools down, but we get a warm spell.  The symptoms develop more commonly during hot, droughty periods that were preceded by cool, rainy conditions.  As most lawn diseases this leaf blight is just another type of fungi that lives in the soil thatch year-round and develops when conditions are just right for it to thrive.

When the leaf blight shows up on the lawn, it looks very much like your lawn is dying.  If you don’t know what to look for you might think that your lawn was ‘burned’ or ‘bleached’.  The leaf blade of the grass will turn straw colored very quickly.  The overall appearance of the lawn (in the affected areas) will look like its drought stressed or dead.


Leaf blight, in comparison to drought stress or a dying lawn, can appear overnight or within a day or two.  Leaf blight, fortunately is not a blight on the crown or root portion of the grass plant.  It generally affects only the blade, and does not kill the crown or root of the plant.  If you look carefully at the grass blade, it will be straw colored from the tip down, but will be green at the base.  Because it is not damaging the crown or root, the lawn will recover on its own.

Conditions that bring on this disease can be the following

  • Mowing during the heat of the day seems to be one of the factors that cause this disease to become active.
  • It mainly affects bluegrass and it is usually on lawns that were mowed too short, or too often.Blight.jpg
  • Dull Mower blades will contribute to the severity of the disease. Your lawn mower can even spread the disease around on its wheels or mower blade as it moves up and down your property.  – you can see in this picture how mower wheels spread the disease around:


As stated previously this leaf blight will recover on its own within 2-3 weeks.  If you want to improve the recovery time, or prevent the issue altogether you can try the following:

  • Reduce thatch (where fungus spores like to lay in wait) by aerating your lawn regularly.  This will allow better water flow deeper into the soil.
  • When the disease is present reduce your mowing frequency, and increase your mowing height.
  • Avoid mowing during wet weather and/or the hottest part of the day.
  • Collect your mowing clippings to reduce the spread of the disease and/or the severity of the disease
  • Fungicides in this instance are very expensive, and literally unhelpful, as the damage has already been done.  Again the lawn will recover on its own.

If you are seeing any type of leaf blight in your lawn, and need some help with it, don’t hesitate to call the Weed Man! 208-888-9911  #wecareforyourlawn







Rusty Razor Sharp Blades of Grass


It’s a gloomy, yet great day in the Wonderful World of Weed Man.  The sky is overcast and threatening to sprinkle rain down upon us!  Hopefully it holds out so we can get some work done!  Last week we began the main part of our lawn disease series by discussing Necrotic Ring Spot.  Continuing on this week, we will delve into the topic of Rust.

Rust?  Yes, you can get rust on your lawn.  But your lawn is not metal you say.  Well, it’s not really rust in the conventional sense.  Rust Fungus is a disease that occurs on many types of grasses when their growth is slowed.  The actual name of the fungus is Puccinia spp.  This typically happens late summer, or early fall.  In fact, I noticed some on my lawn as I was mowing it this weekend.

Rust is fairly easy to identify.  Rust will causerustbuckets.jpg light yellow spots or flecks on the grass blade.  The spots will enlarge over time and create little spores that appear as orange-yellowish powder.  It looks very similar to actual rust that you might see on oxidized metal.  Hence the name ‘Rust.’  Walking through grass with significant amounts of infection will disturb and release the spores within these pustules and leave a distinct orange color on one’s shoes. These spores, carried by the wind or equipment, spread the disease to other areas during the growing season.

As mentioned before, when the lawn starts to decrease its growth rate, rust can begin to develop on the lawn.  Drought, or low water availability will slow down growth.  Lack of nitrogen nutrients can do the same thing.  If a lawn is over-watered, it can deplete the available nitrogen quicker than if it were to be watered as recommended.  Rust is more likely to develop when temperatures are cooler, early morning dew is heavy, and the sky is overcast with clouds creating a low light high humidity environment.

Alternating weather patterns changing in cycles from cool wet weather to hot dry weather can also create suitable conditions for the disease. Rusts survive on living and dead leaf tissue and in the thatch layer of turf grass and/or on alternate hosts (such as barberry or other ornamental plants) when they are not affecting the grass blades. Only when weather conditions become suitable do they begin to cause a concern on the lawn.


Rust is considered a minor disease in turf grass, but I can become severe, or create opportunity for more damaging diseases to start on the lawn.  In most cases the spores will only attack the leaf blade causing wilting and thinning of the grass.  The rust will interfere with the grass blades ability to photosynthesize.  As the grass becomes weakened it is more susceptible to other diseases and/or pests.

So what do you do if you see rust in your lawn?  Here are some great practices to help get rid of the rust:

  • Provide a light application of fertilizer to help promote recovery.
  • Reduce thatch with core aeration
  • Reduce shade and improve air circulation
  • Avoid watering at night
  • Water deeply and infrequently to increase growth
  • Mow the lawn frequently to keep it at a moderate height. Also, be sure to rinse off lawn equipment to prevent the spread of disease.

Rust generally does not need a chemical control.  Although there are chemicals that can help control fungus in the lawn, we generally do not recommend it.  There is a time and place for use of chemical treatment, but too often homeowners just want a quick fix.  Many times chemical control for fungus treats the symptoms and not the underlying cause.  Chemical control can get very expensive as it needs applied consistently and often to work.  If you make the necessary changes to your cultural practices it will improve on its own.

If you are seeing rust in your lawn, and need some help with it, don’t hesitate to call the Weed Man! 208-888-9911 #wecareforyourlawn

Necrotic Ring Spot: The Zombie Apocalypse on Your Lawn


It’s September!  Fall has begun to unveil itself, and the crisp cooler temps have come to the Wonderful World of Weed Man.  Welcome back!  We appreciate you joining us for the next installment of “Your Lawn May Have the Sniffles!” series.  We will be discussing the various lawn diseases we find in the Treasure Valley at this time of the year.

We will begin with Necrotic Ring Spot.  Walmart has the Halloween gear out already, so it seems appropriate to start with this lawn fungus.  It sounds like something you would associate with a zombie.  After all, Necrotic Ring Spot is a parasitic form of plant life: fungus.  It is fitting.  If you see Necrotic Ring Spot on your lawn, the lawn zombie apocalypse has occurred.


Necrotic Ring Spot, or NRS, is a fungus that attacks cool-season grasses, particularly Kentucky bluegrass.  The fungus in question is a soil-borne fungus called Ophiosphaerella korrea.  That was a mouthful – we will just stick to NRS.  NRS is a pathogen that will infect and kill the crowns and roots of the grass.  Essentially the disease spreads throughout the lawn in the form of spores.  Wind, air, water, and animals (even humans) can spread these spores.  The spores, once transferred to the soil may lie dormant for years until the perfect storm of conditions appear for it to thrive.

So what are the ‘perfect storm’ of conditions needed to produce this parasitic lawn disease?  I’m glad you asked!  NRS can be caused by improper mowing and watering.  Because Necrotic Ring Spot is a root disease, it is important to have a healthy and thriving root system for your lawn.  When you continually mow below a recommended mowing height your grass roots will become stunted and unhealthy.  NRS finds it easier to attack the root system.

Fungi happen to like water as well.  At a certain point, if you are watering too much, you stop watering the way the lawn needs watered, and start watering the way a fungus needs watered.   Are you using cultural practices that create favorable conditions for your lawn and unfavorable conditions for lawn disease?  Or is your lawn seeing the opposite?  If you are unsure on recommended practices, you can check out our articles on mowing and watering.

NRS can also be a brought on by compact, high nitrogen soils as well.  This is one of the myriad of reasons we choose to use a slow release granular fertilizer, and recommend annual aeration.

Warning:  Rabbit Trail! – Slow release granular fertilizers will slowly meter out small amounts of nitrogen over a long necrotic-ringspotsperiod of time.  They generally are not real heavy in nitrogen either.  Some fertilizer products might be as high as 48% nitrogen, and a quick release fertilizer as well.  That is a lot of nitrogen released in a short period of time.  Will every lawn treated with a quick release fertilizer with heavy levels of nitrogen all get NRS?  No, however, they can be more susceptible to the disease if the other conditions needed are met as well.

During cool, wet weather circular patches of infected turf will develop.  Though the disease develops in cool weather, the summer heat and drought stress can make the symptoms much more noticeable.  You will start to see the ‘rings’ stand out more and even spread in diameter up to 2-3 ft.  The rings start out light green, then turn yellow.  Over time, if the underlying causes are not addressed, the disease will progress.  The yellowing rings will turn brown or black and leave a sunken bare spot eventually.  The interior green area most times is the lawns attempt at recolonizing the infected areas, but sometimes the internal area will die off as well.

It can get pretty gnarly, and not in a good way. 


If you happen to get NRS in your lawn, here are some great management practices to try:

  • First and foremost, fix the underlying cause of the disease, not the symptoms.  NRS is only found in moist or wet areas with poor drainage.
  • Prevent your lawn from becoming droughty. A lawn requires 1 to 11/2 inches (3-4 cm) of water weekly. Traditionally you should water deep and infrequently – but if your soil is very compact, your lawn will not drain very well.  According to recent theories a lawn should receive light, frequent watering to control Necrotic Ring. Do this until you can aerate your soil which will improve the drainage.  WATER SHOULD NOT BE APPLIED AT NIGHT. Water laying on grass plants overnight encourages disease to spread in the water droplets.
  • Mow your lawn frequently to a desirable height of 3 to 4 inches with a razor sharp blade.  This will help strengthen the root system to help fight off the infection.
  • When the disease first occurs rings may be dug out with a shovel to rid the soil of the disease spores. Remove the grass and soil to a depth of 6 to 8 inches (15-20 cm). Wash the shovel before using it again.
  • Rake the area open; fill in the hole with some potting soil to create a seed bed.
  • Over-seed the area with a perennial rye grass seed mixture and rake the area lightly. Step on the area lightly to ensure good seed-soil contact. Keep the seed bed moist for at least 21 days.
  • If the area becomes so infected that removing the rings becomes unreasonable, correct maintenance practices must be used to control the problem.
  • Use fertilizers with moderate to high amounts of phosphorous and potash
  • Maintain adequate nitrogen levels using a balanced fertility program
  • Reduce soil compaction with an aeration

If you think you are having disease issues in your lawn, give us a call!

Promoting a healthy lawn is the key to preventing Necrotic Ring from appearing. Have your Weed Man fertilize your lawn and advise you on correct maintenance practices to ensure a healthy disease free lawn. Fungicides are not an economical form of control. They are regarded only as a temporary control.

Fungicides only control Necrotic Ring until heavy rains wash the fungicide off the grass blade. Fungicide applications would have to be done every 10-14 days all season long and are very expensive. The Weed Man strongly advises against the use of fungicides. Cultural control is superior and more effective, and cheaper!

If you think you are having disease issues in your lawn, give us a call!  208-888-9911 #wecareforyourlawn



Your Lawn May Have The Sniffles!


Welcome back to the Wonderful World of Weed Man!  As summer is coming to a close, there is still much that can be done to take care of your lawn.  One to two more fertilizers can be applied to help restore health and nutrients back to your heat stressed lawn.  Fall is literally, (yes, literally in the truest sense of the word) the best time to treat weeds.  You can also aerate your lawn as well to help open up the soil to allow air, water, and nutrients to flow better where it is needed most – the root system.  As summer winds down, all the lawn problems you have been having will go away…….

That is not entirely true.  Fortunately, MOST lawn problems get out of hand in the summer.  Unfortunately, as the weather cools down and we begin to enter the autumn season some lawn issues can remain or begin to become a problem.  Primarily, lawn disease.  Yes, your lawn can get a disease.

Lawn diseases can occur at any time of the year, even in summer.  Essentially lawn diseases can be a varying type of fungus.  Mushrooms are the most common and least harmful to the health of your lawn.  There are many others though, such as necrotic ring spot that are not as pleasant for your lawn.  Some even have interesting names such as: fairy ring, pictured below.  Each is distinct in its formation; each is unique in its presence on your lawn.


Lawn diseases can occur at any time of the year, even in summer.  However, we tend to see more disease during the fall months than any other season of the year.  This is the time of year that we seem to spend a lot of time discussing disease prevention with our customers.  To provide more information, we wanted to post a series of articles about the most common lawn diseases we encounter.

Throughout this series we will be discussing causes of lawn disease as well as solutions to wipe out the problem.  In all reality, there is not one solution for ALL types of lawn fungus.  Most of the time a change in watering can help as well as fertilizer.  However, some lawn diseases thrive on nitrogen – so more fertilizer in those instances would make the issue worse.  As stated earlier, each is unique in its formation – therefore, the solution may not always be as simple as adding more fertilizer, or spraying a fungicide on the lawn.

Since we are less than 1” of annual rainfall necrotic ringspotaway from being classified as a desert we generally wouldn’t see many of these types of fungus grow naturally in our area.  A homeowner’s unfamiliarity with proper watering and mowing techniques, or general lawn care, will not cause the disease.  However, it can create the exact environment needed for a disease to thrive!  Even in a desert climate, the spores of the fungus are present.  Stuck in the soil, waiting patiently for the perfect storm of conditions to culminate so it can flourish.  Millions of them.  Just there.  Part of nature. Waiting.

In this series we will begin with the five most common lawn diseases we encounter.  We may add to it as time progresses, but to begin with we will start with these five:

It will be too difficult to discuss all common diseases in one posting, so we encourage you to check back each week as we progress through the five most common lawn diseases we encounter.  In the meantime, if you are experiencing a lawn issue don’t hesitate to give us a call! 208-888-9911 #wecareforyourlawn