Lawn Care Myth or Facts?
There are many misperceptions about lawn care. We encounter them often and wanted to educate people on the most common myths/misperceptions.
“We got rain this week so I don’t need to water my grass. “ (MYTH) Often times our rain events do not accumulate significant amounts of rainfall. For example, if a rain event totals 2/10 of an inch, and you skip watering your lawn for a week, it will get behind because CSU recommends an inch of water per week. People do this all the time and do not understand when their lawn gets super dry or heat stressed because “we had rain”. Even if a rainfall is about an inch, when people turn their systems off entirely, they often times will forget to turn them back on! Ascochyta Leaf Blight and/or heat stress can be the result from a system turned off and forgotten about. Best practice is to have a smart controller which has a rain skip or monitors the weather for you and will skip itself when adequate moisture is detected. Before this first rain in May, soil moisture was less than 9%! Post rain it was 15% which is still below average for this time of year see graph below. Rain is great and it helps but doesn’t replace consistent moisture from an irrigation system. https://www.greencastonline.com/tools/soil-moisture

I can’t turn my sprinklers on till after Mother”s Day; the system could freeze. (MYTH) Soil temps by early April are well above freezing and the ground is not frozen. You can check this website to see what soil temps are at in your specific area. https://www.greencastonline.com/tools/soil-temperature The after “Mother’s Day benchmark” is for young seedlings or plants bought from a greenhouse, or for planting seeds outside since a hard freeze could damage or kill them. Your sprinkler system will not freeze from a hard overnight freeze, if you leave your insulated back flow cover on till overnight lows are well above freezing. I was recently reading a neighborhood thread about this and someone commented they turned their system on in April last year and they had problems. I asked if they left their insulation on their back flow and they never responded. The biggest mistake people make is taking their cover off too soon. Everything underground will not freeze it is the above ground areas, you need to worry about. Here is a picture of soil temps in late March to early April and showing temperatures well above freezing underground.

Thatching grass clippings creates thatch buildup in turf. (MYTH) Allowing your glass clippings to be put back into your lawn is beneficial. If you wait to mow until the grass is 6 inches long then leaving large clumps of mowed grass on a lawn isn’t ideal. If you mow regularly, leaving the lawn clippings is beneficial. Read our blog post about thatch to learn what does cause thatch buildup here.
Lawns retain moisture from rain like sponges for more than a few days (It rained last week so my lawn should be fine.) (MYTH) Before this first rain in May, soil moisture was less than 9%! Post rain it was 15% which is still below average for this time of year. Rain is great and it helps but doesn’t replace consistent moisture from an irrigation system. Here is a soil moisture map for the country. You can always check how much soil moisture is present in your area. https://www.greencastonline.com/tools/soil-moisture Cultural practices such as aeration are needed to cut surface tension and allow water to absorb more efficiently. Runoff still happens and that is why we have gutters, storm drains and retention ponds. When in doubt go out and touch your soil – best way to raise your awareness on these common myths.
Irrigation system comes on therefore my lawn is not dry. (MYTH) Just because your irrigation system runs doesn’t mean your lawn gets uniform coverage. Please read this informative document from CSU about Brown Spot Diagnosis which states “the most common cause of brown spots in lawns is poor or improper sprinkler coverage.” The simplest way to assess sprinkler coverage is to walk around and touch the ground in different parts of your lawn. The picture below shows a system “that comes on but isn’t working properly!”

(Related myth) My lawn looks horrible therefore I must have a fungus or insects and it is not irrigation related because my system comes on so I applied fungicides and insecticides but they aren’t working so I called you. The type of person, who makes such statements, usually misapply chemicals, without a proper diagnosis, and we often find it is irrigation related. The picture below shows a lawn, where the potential customer made the statement above and guess what, had a broken sprinkler head. The homeowners still asserted it couldn’t be irrigation related. 😳 Fungal issues do exist and insects can damage lawns for sure and need to be diagnosed before applying chemicals willy nilly.

We have mushrooms so we applied a fungicide. (MYTH) Mushrooms are a sign of healthy biology in your lawn! Please don’t apply fungicide to mushrooms. Here is a short video from CSU talking about why you have mushrooms in your lawn. https://www.youtube.com/watch?list=PLF923A9DD3BD61E42&v=Bl3U8rT0Uts&feature=youtu.be&fbclid=IwAR0MazoXzpwtQ6K91e1PuzaF5aRpOuEaGx5Ef4mRl0dK0Kxmayt9xM7wj70 Over-application of fungicides and insecticides without proper diagnosis increases resistance and is causing problems (see article below) – please touch your lawn first and assess sprinkler coverage and get professional help for assessing lawn diseases and insects. https://www.insider.com/people-getting-sick-from-drug-resistant-mold-in-homes-gardens-2022-4?fbclid=IwAR20EYWIkxNXzf4bQPWVzpYvfiq8c_lQNFCxLooIyb2_rXXoaqbI9ad0dzI
Watering morning and evening is the best practice for watering. (MYTH) Watering your lawn too frequently leads to thatch buildup, shallow roots and other lawn problems. The Cycle and Soak Method is a great water conservation tool and reduces runoff.

Spring is the best time to aerate lawns. (MYTH) We have found Fall is better because when we come back the following spring in March, plugs still breaking down and holes open for 6 months! Think of all the air, moisture and nutrients reaching down into the grass root zone during that time! With spring core aeration we find the holes close up faster and plugs break down quicker because of heat and irrigation systems starting up.

Spring is ideal time to seed lawns in Colorado. (MYTH) Save your money and do it in late summer/early Fall. Spring weather is volatile and can get hot super fast which can kill young seedlings. We do our over-seeding in late summer when the weather is still warm and the overnight lows are cooling down. The daytime heat helps with germination and the overnight lows allow young seedlings a respite from the heat and time to recover. Irrigation systems are still on and are utilized to keep the seed moist and young seedlings from drying out.
It doesn’t hurt my lawn to mow it super short (1 inch). I have always done it this way and that is not why my lawn is struggling. I like it to look like a putting green. (MYTH) Putting greens have a totally different grass type than residential lawns. Mowing more than 1/3 of the blade of grass off Kentucky Bluegrass and Fescues, stresses the grass out. Short grass is weakened over time and more susceptible to lawn diseases, heat stress and insect damage. A short lawn allows weeds to grow better! Taller grass naturally chokes out weed seedlings. Learn more about proper mow height here.

Why isn’t my lawn green like my neighbors? (I pay you and your program isn’t working. MYTH Customers who mow super short, essentially cut off all the beautiful color. We usually point out the neighbor’s lawn is much taller than theirs and receives consistent irrigation and proper mowing height. The lawn pictured below was below proper mow height and lacked color. The mower blade needed to be sharpened and mow height raised. These small changes made for a much greener healthier lawn in just a couple of weeks!

Fertilization will fix all my problems in my lawn! (MYTH) We love fertilizer and it has amazing benefits and also limitations. Just because there is a product called Miracle Grow doesn’t mean fertilizer can fix all your lawn problems. The lawn below hadn’t had any water in a few weeks, during the hottest part of the summer, and the homeowner thought fertilizer would help!! Think crunchy super crunchy dry grass. 😳 Fertilization needs irrigation to have a healthy lawn. You can’t have one without the other. Fertilizer on a drought/heat stressed lawn can potentially be very damaging.

Related Myth : I thought your fertilizer program would help my lawn fill in. 😳 Hmm, irrigation has been on for 3 weeks and this large section isn’t greening up at all. It is mid-May and more than 6 months since your lawn has received consistent moisture. Winter kill is a thing in Colorado and we are seeing a lot of it. The second picture below shows weeds growing healthily which means the grass is not coming back. Just because there is a product called Miracle Grow doesn’t mean grass can grow from dirt or fertilizer will help fill in large dead or bare spots. We wouldn’t expect to apply Miracle Grow to our vegetable garden and expect vegetables to grow without planting seeds same goes with grass.


I have crabgrass (in April.) (MYTH) Crabgrass doesn’t germinate till late May/early June depending on temperatures. There are many undesirable grass types in lawns besides crabgrass. Here are some Grassy Weeds we have highlighted as a starting point.

I just set it and forget it and my sprinkler system does what it is supposed to. MYTH Spring, Summer and Fall timing of watering should be different! What is sufficient in April and May will not be enough in the hot summer months. Seasonal adjustments are needed. Consider investing in a smart controller to help not get behind with irrigation settings. Below is a helpful chart from CSU’s Cycle and Soak Handout to help you water smarter. https://myecoturf.com/irrigation-cycle-soak/
