Grass in Colorado (or just Kentucky Bluegrass in general)

Getting a good watering schedule is both an art and a science. Disclaimer: I have no experience with KY bluegrass. I did have a fescue yard once, which is typically mixed with a little KY BG. So, you might have some other type of grass mixed in there. It's a newer lawn, so I wouldn't worry about it much or do anything drastic until it has been established for 3 seasons. You will likely need to aerate and overseed every few years, but it is too early for that.

When I was in central TX, I had a new yard put in and was not going to watch it die on me. So, I turned to the internet. Texas A&M had some good info on evapotranspiration rates that told me the ET for my area and the crop coefficient for St. Augustine grass, and good instructions on how to calculate how much to water. I built a spreadsheet for every month of the year to set my watering times.

The other variables are how much water your system puts down, and how much water your soil can actually take at one time. Best to measure in multiple places, and know that zones typically overlap -- that's where a bit of the art comes in. Not every spot gets an overlap, so you have to find that happy medium. Also, you have to watch for when water starts running off or pooling -- that means the soil needs some time to soak it up, so you may need to do 2 programs of shorter times to allow some time for the water from the first round to soak in. As the other poster mentioned, better to do longer cycles a couple times per week with some days in between, but you may want to do 2 rounds at 10-15 minutes rather than 1 round at 20-30 minutes. Some of this depends on the type of sprinkler heads you have -- spray heads dump a lot of water evenly in a short time, while rotating heads take much longer but cover a larger area.

I checked out this site for CO --> https://coagmet.colostate.edu/cgi-bin/extended_etr_form.pl

For today's date in Fort Collins, the ET for cool season grasses appears to be 0.21 inches. So, for this time of year in Fort Collins, grass needs roughly 1.5 inches per week (0.21 x 7 days). So if you know how much water your sprinklers put down, you can do the math to make sure it is getting that 1.5 (or whatever is needed in your particular area). Keep in mind that this ET rate changes through the year with temperature, and you can adjust based on rainfall. Should be enough historical info at the site above to get you in the ballpark -- it doesn't have to be exact, just close. That way you know it is getting enough, but not too much and wasting water. I didn't want to be changing programs every week, so just kind of rounded off for the month and used the same schedule all month.

This ET method worked great for me, and I never had to use any weed killer, just fertilized a couple of times per year and kept it mowed to the right height.

 

Great info, thanks. I appreciate the link, I will keep an eye on that. Also, you're right about the runoff. I didn't check it this morning, but will try to remember to. I did up the time per zone from 15 minutes to 25 minutes so that's something I will need to check.

 

Kentucky Bluegrass grows well here as long as it gets sun and water during the summer. But it will dry out quickly and be quite toasty by July/August when water is at a premium and temps are in the 90s to near 100.

Ironically KY BG actually grows better 200-300 miles north of the Central KY region because it prefers the cooler temps.

 

Yeah runoff is important to track. Watering beyond the soils ability to absorb it is literally money down the drain. Every yard and situation is different. Hell...my front and back yards are different.

Trial and error mixed with a bit of science. You'll figure it out.

 

What @Plain Jane Taco said. Water it out would be the best practice. The grass isn't dead, it's stressed. You could lightly tuft it up with a wire rake to help the grass blades stand back up but I wouldn't really go beyond that. I agree with the Miracle-Gro, that might work but in my opinion, it'll grow back with time and a good watering schedule. Mow, mow, and mow some more, twice a week and keep up the watering regimine. I didn't know about the water coefficient stuff, I'll have to take a peek into that.

-J

 

Gotta ask the experts... what about mushrooms... my little research has shown that they’re actually a good thing for lawn but they’re hideous. How do I get rid of them and stop them from coming? My watering schedule doesn’t deter them, if I reduce water they still persist and my lawn suffers. Most of my lawn looks nice but I think I have a grub issue as well so I have a grub killer I’ll lay down for that.

 

I upped my watering due to advice on this thread. I have mushrooms and the yard looks a lot worse. I may have to reduce it, maybe I had it right before. Sorry I didn’t answer your question, but more water seems to bring mushrooms.

 

What did you do for your watering schedule? For two weeks I did deep watering (25 min) twice a week and my grass started to brown in some areas. So I went back to 15 min per day. I do however think that I need to add a 30 minute cycle once a week for a deep water based on what I just saw when digging in my yard.

You can see in the pics that some areas of the grass is lush and green with healthy green blades from top to bottom. Other areas are looking sad.


Beautiful, thick, and lush green grass..


A sad areas




And from digging a little, barely 2” down the soil is getting pretty dry. I think my grass needs deep watering still but maybe once a week I’ll increase a morning water to 25 or 30 minutes.




Also, I see no evidence of grubs. The local garden center suggested I may have them so I needed to verify.

 

I went from 15 minutes, 3 times a week, to 25 minutes, 2 times a week. It may look worse due to the hot and dry weather, I’m not sure if it was the watering that did it. All of the grass in my area looks pretty dry.

I am also going to do another round of organic fertilizer today, I’m at the low end of when they recommend another application.

My front yard looks good, one of the better in the neighborhood. The back yard looks like there are like 5 different types of grass fighting to take over. It almost looks like a field and not a yard with sod planted. It’s very odd, I am hoping the good sections take over and even it all out. It is to the point of possibly starting over, which I don’t want to do.

 

My local garden center is advising that for my area I water 3x a week for 30 minutes. So I’ll try that, you may want to do the same since we’re in similar climates.

One thing I did notice when walking around the yard with the sprinklers on is that I’m not getting uniform coverage. If I have a sprinkler head that gives say 4 foot radius of water spray, I’m not getting water through the entire area. Some areas next to the head isn’t getting water while others are. Is there a better sprinkler head to use that distributes water more evenly?

 

Ill try to tackle these one by one so this may come off as a bit scatter-brained.

Mushrooms. Mushrooms tend to thrive in damp soil and darkness which is why many people notice mushrooms have grown up during the night. While they aren't the end of the world, it's just a sign that your grass has fungal growth. Typical cause of mushroom growth is allowing the grass to go to bed wet or damp. Now we can't control mother nature, we can control our watering schedule. We try to water in the early morning which will allow the grass to spend the rest of the day drying out in the sun, however on days with heavy cloud cover, this may be impossible. I mentioned earlier about cycling different fungicides to help treat and prevent fungal growth. Think of it this way, on of the reasons that Dr's don't want to over-prescribe antibiotics which could result in drug resistant bacteria, we don't want fungicide resistant fungal growth. We like to cycle the "Fungicide Triangle" Here's a good article on the differences between the groups so I wont go to in depth here. Basically, every year you want to treat from a different fungicide group.

I believe certain types of soils will hold moisture longer than others. Sandy soils will allow water to pass quickly through them and have a low water holding coefficient whereas clays will hold water a lot longer. Take that into account when your watering your grass.

Here's some options for you to get you started that are relatively inexpensive. These will treat a variety of yard fungus from brown patch to dollar spot. Acropetal means that it protects the exterior of the plant and forms an exterior shield to prevent new growth where as Systemic is more of an internal to the plant curative/preventative along with an exterior protective shell. I also included a link to a PDF that gives you some options. Important takeaway would be to follow the directions on the label and treat accordingly. This isn't one of those 'Throw'er down' types of treatments.

Banner Maxx II Group 3. Acropetal Penetrant
Proturf Systemic Fungacide Group 3. Acropetal Penetrant
Herritage G Group 11. Systemic Action
Scotts Lawn Fungus Control Group 1. Systemic Action

This PDF gives you options if you're into lists and charts.

Your backyard is more than likely fighting off different grassy weeds. I'm kinda in the same boat with my front yard. I believe the previous owner over-seeded with a bermuda type broad-leaf so its fighting with my Centipede. Some garden centers if they have a Turf manager on staff should be able to tell you what type of grass/weed it is so that you can research a targeted herbicide to treat that invasive grass cultivar. Another approach would be to get plugs. A tool like a core

$45 5-in-1 ProPlugger Bulb Planter - Long Handle, Sod Plugger, Weeding Tool - Made in USA

plug remover or the equivalent would help you plug your yard. Basically, you can take good grass plugs from a section of your yard and transplant them to another area of your yard that you want to treat or fill out. Make a 6 - 9 inch grid of holes and plug away. The neat thing about that pro-plugger is that you can make plugs easy as shit with it, depending on how deep you plunge, you can get like 10 plugs in one pass. Turf grasses are very resilient and will overtake weeds when properly treated.

You might want to do the sprinkler test I mentioned above. Check your sprinkler output to see how much water your heads are putting down. Ill paraphrase: make small platters from cut down Solo Cups to like 2 inches tall, like 5 or more. Scatter them throughout your yard in various places and run a full cycle of your sprinklers. Once sprinkler cycle is complete, go out and measure how much water is in the cups. Once a zone has completed, you can go check those cups if you're worried about evaporation. I cant remember what you said your grass type is (I'm sure I could scroll up and look) but you'll be able to check to see if your sprinklers are running long enough to give you your weekly rate. If your running twice a week, you'll halve that rate, etc. I hope that makes sense. See my quote below for a better explanation.

I removed the pictures that I'm not going to cover. The first sad area looks like a lot of heavy thatch buildup. Hell, your whole yard looks like heavy thatch buildup. Lets see if we cant find the root cause (pun intended) of this issue. I believe that you have a patio overhang above this first sad photo, are you getting a lot of water runoff pooling in this spot? I saw a downspout in one of your other photos but check your drainage of your gutters to make sure you're not overflowing and unnecessary water is pooling there. Any pets in the household? Is this a spot that they like to pee if you have pets? If I remember correctly, you said you lived in either Flagstaff or Prescott correct? I'm originally from the Valley so I kinda know what your dealing with up there but I haven't lived in AZ for a long time and a lot longer than I gave two shits about lawn maintenance. Now wouldn't be a good time to de-thatch your lawn or core aerate. Some thatch is good dont get me wrong, but heavy thatch is bad. You're choking out the base of the plant. I would de-thatch your yard around mid to late September and then follow up with a core-aerate. After you core-aerate, top dress with either mulch or sand and rake evenly across the yard. You may over-seed prior to applying your top dressing and then continue watering like normal until the yard goes dormant.

-J

 

Awesome post, as always, thank you!

I noticed something the other day when I was sitting outside in the morning. The way my house is positioned, it's almost perfectly lined up east to west. The sun rises directly in front of the house, and then sets directly behind it. I noticed that the house casts a shadow that covers the middle of the back yard for a while, while the sides are getting sunlight. It's almost as if the areas where the sun hits for a lot longer, look great. The area that falls into the shadow is where the grass doesn't look healthy. There's obviously nothing I can do about this, but it was very obvious in the morning. The front gets great sunlight, which is probably why it looks good.

 

There are specific Kentucky Blue seed varieties that are shade tolerant such as True Blue and Brooklawn, and you're in luck. You can buy some here. I don't think there's much that you can do for this year since you are already halfway through your growing season, but if you ordered about 10-15 lb worth of seeds, it should show up in time for your overseed schedule. Blends are a best of both worlds and to over 95% of the population wont even be able to tell the difference. Seed is cheap so you can go heavy handed when you overseed. When I say cheap, its generally cheaper then sod patches and redoing your yard in a new cultivar. I overseed heavy since about half of the seed will take root and seed is cheaper than a renovation. With overseeding, you should be able to keep your normal watering routine since the ground will stay wet because of the coverage and shade from the existing grass. Let me start over. To overseed, youll want to accomplish that at the same time as when you de-thatch and core-aerate prior to you applying mulch/sand topdressing. Typical overseeding occurs prior to winter dormancy, that way when the lawn wakes up in the spring, the new seeds should be establishing or in the beginning stages of establishing.

It's not impossible to overseed now, you just have to up your watering schedule to every day lightly. The seed needs to keep damp without water runoff. After overseeding, wire rake the seed so that you get good soil contact which is why it is suggested that you de-thatch prior.

You can overseed on your side lawn since it gets more sun to a brand of kentucky blue that is more sun tolerant if you want to keep that up. Keep in mind that the sun moves around in the sky throughout the year so areas of shade in June, could be getting more sun in August.

-J

 

I realized that I missed the second part of this so instead of going back and editing my initial reply, i'll just continue it here. Typically sprinklers are set up to give head to head coverage, meaning that one sprinkler will cast water to the head of the surrounding sprinkler head(s). What brand sprinkler heads are you running? I know Rainbird has replacement heads for most of their models but you'll need to find out how much pressure is coming out at the source. Unfortunately, I don't know of an easy way of testing water pressure without some crazy plumbing contraption. I was initially thinking that you might be able to make an adapter to connect to each of your sprinkler heads with a pressure gauge on each but you'd have to fabricate every one separate unless you capped all the sprinkler heads in one zone and only checked the pressure at one head per zone. I'm sure there's an easier way to check pressure like something before and after the backflow preventer valve. You might be able to hook up a water pressure gauge up to there and check water pressure. If there's a huge discrepancy, your valve might be needing to be replaced. Once you know the pressure at the source, you can select the appropriate heads for your sprinklers. I'm a fan of the Rain bird MP Rotator heads for even coverage but whatever model you choose should have a coverage chart based on the PSI at the source. If the area is mostly windy, low angle sprinklers help keep the water where you want to go. Typically, heads are high angle but you can find low angle heads special order. I don't see that you'd need low arc to keep it under trees or obstacles so I'd just go with the standard option. See this PDF for example.

I believe most sprinkler brands will have an internal screen filter as well. There's typically a special tool to help pull the inner core out to allow you to clean the filter. I'd start with the sprinkler head that isn't spraying like it should. I'm about to leave work so I'll have to cut this short. I hope some of this helps to answer your sprinkler questions.

-J

 

First, thank you so much for the helpful info. Second, sorry it took a while to respond. I needed to wait till I had a moment at my computer to respond thoroughly and appropriately to all of your information.

Thanks for the fungus information. I did run a rake over any mushroom areas and cleaned up what I could. It's been a couple days and I haven't seen any new growth of the mushrooms. I'm sure they're still there but may take more than a day or two for them to show again. I have heard from a few sources that mushrooms are hard to get rid of since they are a very deep rooted plant. I have also head that they are a good sign of healthy soil and are good for the lawn since they provide nitrogen and help break up decay. For now I think I'll leave it alone and let the mushrooms run their course unless they start to become too much of a nuisance. Raking the tips off for now may satisfy me.

The sprinklers are going to run again tomorrow morning so I'll set some cups down and measure what they are putting out in a 30 minute cycle. I'll do this in several areas and come up with an average. This will also help me determine where I may need to change some sprinkler heads since I don't believe I'm getting the proper coverage.

I looked a little close at the layer of thatch and then did a little reading on proper thatch amount and what to do about it. I would guess my thatch layer is about 1/4" and based on what I have found, this is an appropriate level. Anything above 1/2" needs to be addressed. If I dethatch my lawn now I will leave the roots and soil too exposed to the heat and sun which will cause damage.

There is an overhang but it's above a concrete patio and that overhang doesn't really shade the grass at all. The down spouts have drainage lines that are underground and ran to the street so there shouldn't be any issues there. I have no pets so no issues there. I am in Prescott so the soil here isn't exactly great for growing anything other than weeds or drought tolerant plants... unfortunately, grass is neither.

I did aerate the yard at the beginning of the season and did some light overseeding while seeding and top dressing some problematic areas. Towards the end of the season I'll overseed the entire yard and top dress.

I'll look into checking my water pressure and going from there on my sprinklers. I can check it at the valve for the station instead of at the sprinkler head, this will probably be the easiest way. My sprinklers were installed last year when we had our yard landscaped so I don't know the brand. A few sprinklers settled so I'll check the brand when I raise them up a bit. I have heard good things about rainbird as well so I'll look into them.

The landscapers did a great job in the construction of everything they made but I don't think they specialize in grass or irrigation.

I had a couple trees planted yesterday and the guy from the garden center that planted them gave me some good information as well. He was saying that the soil here is basically "dead soil", meaning that the land here used to be a series of small hills. When the contractors graded the land for the sub-division they took about 10 feet of earth from the top, so everything that my home is on is considered dead... no nutrients. When the sod was laid down, there was a few inches of top soil laid down but not evenly and not in all areas. He suggested that some areas of grass thrive because of that and also some areas of grass just take a little more time due to the ground. He dug in one area that looked like just hard dirt while another area looked sandy. He also suggested to get an iron supplement since this is essentially dead soil. Another thing to note was there is really good rooting of the grass, when he dug for the trees, he showed my that I had roots that were nearly a foot deep. I do believe the grass is healthy due to that.

One last thing to note, I have heard it takes a few seasons to really make the grass look pristine. I'm kind of on my first season since the grass was installed towards the end of last summer. I am inpatient though so I do want it to be perfect now. It just bothers me when I have some areas of grass doing better than others, this may just be due to the soil composition below the grass.

 

Long post, split so it's easier to follow my train of thought.

I haven't heard that mushrooms are good for the lawn so I'll have to take your word on that, however, fungus isn't healthy for the lawn (Rust spot, Dollar spot, etc). The way I see it is that mushrooms are a form of fungus but that's neither here nor there. I do agree with you on how satisfying it is to punt one of those mushroom caps like you're scoring the winning field goal at the Super Bowl. Send IT!

This'll be a good method to see where you have good overlap. Rule of thumb is that you'll want sprinklers to spray "head to head" for good coverage. The cup method will allow you to see what zones/nozzles need to be tended to. I believe that most sprinkler brands will have replacement nozzles for their different heads not necessarily just Rain Bird

That's exactly why I suggested that it wouldn't be advisable to de-thatch your yard right now . I would wait until temps start lowering, however, you said that you already de-thatched your yard in the spring so I would keep up that schedule for next year. Continue spring de-thatching which will help your yard wake up from winter dormancy. I wouldn't advise de-thatching more than once a year since having a light bed of thatch is good for your lawn, just not a heavy bed.

To help with spreading out top dressing and leveling your lawn, look into a landscaping rake like this or if you're feeling froggy, pick up a

$27 FLY HAWK Lawn Leveling Rake | Levelawn Tool | Level Soil or Dirt Ground Surfaces Easily | 18” x 10” Ground Plate | rakes for lawns Heavy Duty 72” Extra Long Handle | Extracted Iron Metal Black

level lawn rake.

It's hit or miss with landscapers, especially on newer builds or lawn renovations. If you've got good pressure at your valve then I would definitely look at a possible clogged inlet filter on the sprinkler head or an undersized spray nozzle.

Finally, I would conduct a soil analysis test. I've heard that

Soil Savvy - Soil Test Kit | Understand What Your Lawn or Garden Soil Needs, Not Sure What Fertilizer to Apply | Analysis Provides Complete Nutrient Analysis & Fertilizer Recommendation On Report

this one is really good but I haven't used it so I can't give you any first-hand experience on it. I would suggest getting multiple tests for different areas of the yard. The mail in tests will give you a nice printout to help you see what Micro and Macro nutrients are lacking in your yard. Dolomite Limestone for raising the PH or the organic way would be to use Wood Ash, whichever you prefer. If you want to lower the PH, you'll need elemental sulfur. These rates will be dependent upon how much you are trying to alter, you'll have to do some math based on 1k sq ft. For micro nutrients, I would spray a liquid application over your lawn. You'll need to know what your needing to push based on what your soil test results say.

For an iron supplement, you have two options: Ironite in granular or liquid. Granular will be a slower burn though the grass whereas the liquid will typically pop in about 1 to 2 days after you apply it. The thing about iron is that it's quickly used up by the grass so the luscious green pop you get from its application will typically only stick around for about 4 to 6 days at best. If you're looking for a head start on which micro nutrients to apply to your yard to level out your numbers, start here but be advised as this is just a starting point, not the ultimate solution to your yard needs. Here's some more options if you want to specialize your yard and want to avoid big box store brands: Granular and Liquid. Whew.

-J

 

@svdude @Boyk1182
Stumbling upon new stuff every day round these parts.
https://www.irrigationtutorials.com/
To much knowledge to direct link to everything but from what I saw, these are free college level courses on all your irrigation needs.

-J

 

That's awesome, thanks, I'll check it out. My grass seems to look very bad lately after a few hot days. It looks very, very dry, almost burnt. Then if we have a few cool days or days with rain, it comes right back and looks decent. It's strange how fast it goes back and forth. The front looked perfect for a while, the back was getting good, but this hot weather is not helping.

 

I'm sure it's just the summer slowdown to dormancy. Nothing abnormal, keep up your regular routine on it and when the temps start lowering and you get some nice rain, it'll pop green in no time.

-J

 

Update: it looks horrible. It was the darkest green on the street. The hot weather has turned it brown, while the others (who I never saw fertilize) have green grass now. I used organic fertilizer that said it wouldn’t burn the grass. I have no idea what to do, there’s no point in even mowing it at this point!