Posts Tagged ‘mowing stress’

Preparing your lawn for summer

Published by JKeefe on June 20th, 2011 - in Cultural Practices, Misc.


Proper mowing height is the single most important thing you can do to your lawn

As June fades into July, there are definite guidelines on what you, as a homeowner should do and not do as it relates to your lawn.  The most important and often discarded piece of valuable turf information is mowing height.  Like a doctor speaking with a patient, mowing is one of the most important pieces of advice a homeowner can follow.  Even if you have your lawn professionally cut, this does not automatically mean the job will be done right.  I have seen too many commercial lawns scalped or mown below 2” during the summer, only to become stressed weakened and prone to both weeds and crabgrass.

So what is the ideal summer cut?  For most lawns, sun or shaded situations call for a high cut at 3” or maybe a little higher.  Sunny areas are prone to stress when cut in the middle of a hot day, predisposing them to all kinds of heat and mower stress.  As the grass is cut, depending upon the sharpness of the blade, the leaves lose water and can brown with the increased moisture demand.  Said another way, if you cut something, it bleeds – in this case a grass blade is mostly water.  When a mower cuts it, especially during the day, and below 2”, the lawn loses moisture rapidly.  If the soil is dry and cannot support replacing this moisture loss, you can see browning the same day or shortly thereafter.  These areas can appear as brown patches, yellowing, or widespread discoloration depending upon the time and day temperature.

The shorter the mowing height, especially as it approaches the 1” level, the more substantial damage can be caused from June through August.  The shorter the cut, the hotter the soil becomes, causing weed seeds to germinate.  Any pre-emergent barrier that may have been put down pre-maturely degrades, allowing weeds to germinate unnecessarily.  Removal of grass clippings may provide an aesthetically pleasing view, but it removes critical organic matter week after week.  There may be an occasion for this procedure, but on the whole, grass clippings should be mulched and returned to the lawn surface like leaves falling in a forest.  This way, whatever energy and professional care you are putting into your lawn will not go to waste but will provide the most benefit possible.


Drought stress, high heat, and sun scald on your lawn!

High heat sun scald on cool season turf

High heat can lead to all kinds of issues in and on your lawn including browning, drought stress, and sun scald.  To break down the process of high heat and or a lack of rain on your lawn, think of how you would feel leaving in the middle of the winter and arriving in a hot climate like Mexico.

Dormancy, drought stress, and mowing damage

The first stage begins as sun scald if the turf has been growing fast and you get some hot, sunny days.  The turf turns white and you may see blotches or patches in your lawn appear virtually overnight.  Cool season grass is exactly that, it prefers cooler weather- not the high 80’s or 90’s- such weather places a huge demand for moisture on a shallow root system.

 At first, there may be plenty of water in your soil, but after a few days to a week, that supply dries up and now the grass starts to suffer- it turns a dull- hazy purple with a blue tint.  This is the first symptom- drought stress- the grass is starting to dry up and is unable to meet the moisture demand of the leaf blade growing.  So now what happens?  The base of the plant is the command center, it is called the crown.  It cannot push out any new growth and now must shut down on emergency power to save itself.

  The second stage is browning- the grass visually turns brown as the once green leaf blades dry up and the crown starts to shut down to conserve what is left and survive.  The good news is, the sooner you water- the sooner your grass will reactivate and start growing again.  Typically, if you get water to your lawn in the initial drought stress mode, you can prevent or minimize subsequent browning and get things rolling again- keeping the grass green without tints of brown or drought stress.

However, if you allow the lawn to shut down and brown out, it can take weeks to a month to regain the green color and previous growth.  Simply put, once she goes brown- better turn around and keep the water running.  Therefore, targeting drought stress is your best option to prevent dormancy and a brown lawn during summer.

 The good news is most lawns just have what is known as “hot spots”- sections with thin topsoil, ledge, septic covers, or sandy conditions.  If you target these “hot spots” first, more often than not you can avoid watering your entire lawn in some situations.  Just look for the drought stress and water those areas instead of the whole lawn.

 What else can be done to avoid and or minimize browning and or drought stress?  Mow high, 3” minimum and don’t cut the lawn at high noon- this is not a western movie- mow in the am or late pm.  Better yet, if the lawn does not need a cut, don’t mow it at all- skip a week or two.  Your heavy tractor or mower will cause more damage by crushing delicate, weakened grass versus leaving it alone.  Fertilizing, liming, and other proactive treatments can keep the lawn healthier going into hot/dry weather and help the grass recover faster.  Avoid high soluble, quick release liquid fertilizer as this can burn and or cause an undesirable- unsustainable flush of growth.  Aeration can help break up compacted soil and allow water to penetrate the surface and down into the root zone.

 In another post, I will discuss when brown grass stays brown and dies.  This condition is not always just from a lack of water, but from insect damage.  Stay thirsty my friend. . .

© Copyright 2009-2014 Chippers, Inc. All Rights Reserved.