When Summers bring HIGH Heat and LOW Rain! (or Turfageddon)

Ed. Note: Update: Spring of 2020: With an early melt in March and promising weather early, Covid-19 shut everyone down for just over 2 weeks. Lucky to be able to safely go back to work, we began spring fertilizers in earnest, before we encountered SNOW IN MAY! That’s right 2-4 days of snow cover depending on where you live. That kind of weather drives humans crazy, and its effect on turfgrass and plants is similar! Plants didn’t know if it was time to grow, or time to go…to sleep. 3 weeks later we encountered mid summer heat waves and are presently (at the time of writing in our 2nd heat wave (consecutive days over 29 deg C or greater) as of June 9th.

Ed. Note: Update: Summer of 2019: April through May were very wet with plentiful rain and cooler more temperate conditions.  This allowed for good turf growth. However Late June and July have brought intense heat and humidity (humidex values in high 30’s). Soils DRY OUT FAST!  It is critically important to allow turf to receive optimum water of 1-2″ per week consistently through high heat, limit activity on stressed turf and mow at the highest setting only as necessary (normally once every 7-10 days when under stress)!

Ed. Note: Update: Summer of 2018 is looking to be another record breaking year of no meaningful rainfall and record High heat days over 28 deg. C (even with the Ice storm in April killing turf for 9 days straight, we advanced to high heat almost immediately. That time is normally when lawns slowly acclimatize to summer and build extensive root systems) 30 days of 30+ heat in 2018 caused plentiful turf issues.

Ed. Note: Summer 2016: All the same applied as we had less than 1/3 the normal rain and  a record number of days with temperatures over 28 deg Celsius.

July 16th 2012: (Observations from the field in the Greater Toronto Area and Southern Ontario)

Spring arrived much earlier than normal in 2012 with a beautiful taste of warm summer weather as early as the middle of March in many regions of Southern Ontario.

The only problem is that it skipped the “April Showers bring May Flowers” part, while homeowners rejoiced in the great weather and enjoyed some early recreation and Gardening.  From turf’s perspective, its Armageddon!

As of now, that beautiful weather has become scorching heat and drought throughout most of the US and Canada.  Corn Crops are suffering large losses and the often forgotten crop of turfgrass, that is planted across the country on home lawns and parks, are mostly dormant.  This is a particular problem in Southern Ontario, Canada and most northern states, as our typical lawns are made of grass plants categorized as COOL SEASON GRASSESThat means our lawns are not suited for tropical and subtropical temperatures.

Weather records show much higher than average temperatures combined with record low precipitation through most of April, May, June and July.  These dry conditions, except for the odd scattered thunderstorm (thunderstorms provide a lot of water in a short span and rarely soak the soil sufficiently) mean the homeowner has to step in to provide a lot of help. Shallow-rooted grass species such as Bentgrass, Annual Bluegrass, Crabgrass and Rough Bluegrass expand and thrive in lawns during times like these (not to mention the broadleaf weeds). Lawns with shallow root systems are more susceptible to drought as the soil temperature is much higher near the surface.

In addition, this lack of rain is causing “Hydrophobic Soil” that actually repels the infrequent watering provided by brief thunderstorms or intermittent and infrequent lawn watering by the average homeowner. (Hydrophobia in soil is best remedied with a surfactant and/or frequent short bursts of watering over a longer period of time until the ground is able to absorb the water more easily (15 min on, 30 min off- repeat!)

This means lawns everywhere are going dormant, but are not dead-yet!  Dormant lawns are characterized by the yellow, brown appearance.  Most lawns can withstand not being watered for up t0 3-4 weeks, however permanent damage or death can occur if they do not receive water for any longer period of time.

Turfgrass plants, just like trees are living things and provide an immense environmental benefit, but they do need to be cared for.  Most lawns will bounce back with cooler temperatures and mother nature’s long rain showers, but how do you make sure?
Here are my 5 best summer lawn care tips:

1. Water deeply at least once a week for about 1.5 -2 hours in each area. Lawns need 1-1.5 inches of water each week to look their best.  Apply the water deeply no more than twice a week to deliver the prescribed amount.
If we have more than 2 days of 28 deg C+ temperatures in one week, than water twice that week!

2.  Mow high, at least 3 inches.  Longer blades up top, support deeper roots below!

3.  Only mow during the morning or evening, and only when the lawn reaches about 4 inches in height.  Mowing in high heat causes mechanical damage from the weight of the machine, and even more stress with walking on it during the intense heat and sun.  Plus the longer blades provide shade cover for the root system and the crown of the plant. (leaving the lawn to get too long and then hacking it down causes even more stress- expect yellowing within days!)

4.  Limit activity on the lawn.  The dormant blades and fragile crowns are easily injured at this time.

5.  Check for Chinch bugs!  Chinch bugs love the heat and sun and can actively be sucking the remaining juices from your grass blades and inserting their turf killing toxic poison while you sit idly by.  Chinch damaged turf will not grow back and you will need to seed and top-dress these areas in September.  There will be lots of time to grow and rehabilitate your lawn during the great growing season of September through November!

5 1/2. Fertilize only with a proper summer-balanced High % slow release fertilizer.  Using the wrong fertilizer can cause surge growth using up the plants vital energy for no benefit.  Better yet, you can burn your lawn by using quick release fertilizers or using too much at the wrong time of the year.

Important Notes: The typical Ontario lawn is primarily the cool season plant called Kentucky Bluegrass.  It is important to note that you need to accept that most plants (including turf) just can’t grow in intense heat with no rain.  Even Organic and chemical Weed Controls are not as effective during high heat as the plant under stress can not absorb it adequately.  It is not reasonable to expect a Thick, Green lawn during times of drought, but with proper care, your lawn will bounce back beautifully in September while your neighbours are left scratching their heads.

Unsure of what to do on your lawn with all this heat? Don’t fret, a well maintained lawn will recover.  Call us for help, we can provide advice and assistance, and provide tips on your watering.  Please leave us a comment, we’d love to help!