It’s Time for Summer Lawn Care!
cues up music “It’s Summertime, Sum-Sum-Summertime, Sum-Sum-Summertime!”
What beautiful weather we have been having these last few weeks! However, with these sustained 80+ degree days, we are starting to see the first signs of heat stress/summer damage in lawns. That makes this week a great time to talk about summer lawn care tips to help you all keep your lawns in peak condition year-round.
Best SUMMER Irrigation Practices:
Watering is at the forefront of everyone’s minds right now. Here is what you should be checking in on with our irrigation systems in established lawns:
Make sure you adjust the timing of your watering program throughout the year so that the last zone is finishing about the time the sun is coming up. This timing reduces evaporation from the sun/heat and it also reduces the amount of time that the water is sitting on the lawn overnight to minimize any chance of summer disease formation. That means it is a win for your water bill and for your lawn, all at the same time!
Make sure that each of your zones is putting out 1/4” of water with each watering. You will need to actually measure the output rather than just set it for a certain number of minutes. The number of minutes will be different for everyone because each home has a different water pressure/watering system, so there are too many variables for us to guess how many minutes will be right for you. To check the water output, put something flat-bottomed with low sides, like a tuna can or a short Tupperware dish, in a few different areas that will be watered in each zone. Be sure to keep in mind that some sprinkler heads are only watering part of a complete circle (along a driveway, for example) and will not have to be on as long as sprinklers complete a full revolution - so make a point to check the output of both of those areas since those timings will be very different from each other.
An established lawn will need 3/4” - 1” of moisture per week, depending on the time of year, temperature, soil type, and evaporation rates due to variables like wind. We recommend avoiding watering every day because this can train your lawn to have a shallow root system and actually stress more during mild drought events.
Have a rain sensor installed on your irrigation system so that your system is “smart” enough to skip days when it is already raining. Some systems can now be controlled with an app on your phone giving you all kinds of nifty levels of maintenance oversight. Check with your irrigation company to see if this option might be available for your system!
Best SUMMER Mowing Practices:
One of the hardest things to do as a homeowner in the summer is to know when to NOT mow your lawn. In Iowa, the vast majority of us have cool-season species of grasses in our lawns; cool-season grasses are great in Iowa because they come back each year after hard winters, but they can start to stress when the temps start pushing the upper 80s and 90s - so we need to do what we can to minimize the stress we put on the lawn.
This large discolored spot to the left of driveway is a good example of what stressed grass looks like when it “grays" due to dehydration.
Try your best to avoid getting into the habit of mowing every so many days like clockwork, without being responsive to the conditions present in the weekly forecast. "Think like a farmer” and look for signs that your lawn is stressed/dehydrated, like graying (see photo). If you see graying definitely do not mow. Instead, increase your watering program for that day immediately.
When it is very hot outside, it is better to let your lawn get longer than you normally would and wait for a break in the weather (usually a rain event) to go out and cut your grass. Cutting your grass when it is very dry will result in damage from the wheels literally squishing the last little bits of moisture out of the plants (pictured).
These two images are examples of grasses that have been mowed during the heat of a dry week. The first thing you will notice is that the damage patterns are in perfectly straight lines, this is a giveaway that the damage is physical damage from a person. (Nothing in nature happens in a straight line.)
Another thing you can do to help protect your lawn from dehydration is to sharpen your mower blades. Sharpening your blades results in a clean cut of the blade with each rotation which is less stress on the plant. A sign that your mower blade is dull is when you can see tearing (or a “fanning”) of the blade which results in additional moisture loss and will turn the tips of the plants brown due to lost moisture. This Old House has a nice tutorial video on how to sharpen your mower blades here.
Mower damage from mowing during a dry, hot week. You can see the mower wheel marks throughout the lawn going back and forth from this walk behind mower.
Mower damage from mowing during a dry, hot week with a rider mower.
“Fanned” tips from a dull mower blade. Fanning like this will result in your lawn drying out faster than if you are getting a clean cut. This is why it is a good idea to sharpen your mower blades multiple times a year. In particular, sharpening them at the start of the season and then again after the grass has gone to seed in the late spring/early summer, will help your lawn retain moisture throughout the season.
Best Summer Feeding Practices:
In general, it is best to avoid feeding your lawn any time the temperature is over 85 degrees. Biologically, grasses do not usually put on much new growth in high temperatures, so adding food to try to push your lawn into growing actually creates stress for the plant at a time when moisture may be more scarce. If you are due for a feeding in the summer, the time is with a forecast that contains a break in high temperatures with strong chances of rain and cooler days immediately following the feeding.
Of course, the easiest way to avoid summer feeding is to not need one in the first place. This is a good reason to consider switching to our 4-Step Program!
And finally, sometimes a little bit of heat damage is just inevitable in a time of drought. Should that happen, always know that 13-13-13 and a little love when the temperature finally comes down and the rains return will help you recover. To adapt what they say in the UK, “keep calm and water (and 13-13-13) on”.