Dying Lawn

(Question)

I’m having a problem where 2/3 of my backyard is dying/dead. We re-sodded the yard in the fall of 2016. The soil in our area of south Etobicoke is very sandy so we put down a 2-3 inch layer of black loam before laying the sod. I have done yearly spring de-thatching, plug aeration, top soiling with black loam, overseeding and fertilizing. It started as a 3 foot ish size of yellowing grass in the middle and small sections near our retaining wall and then it continued to grow to be half of the yard. At first I thought it was from a late dethatching(Early June before the grass was consistently growing) and the excessive heat and drought, but after rain and many heavy waterings that returned the rest of my lawn, the dead area continues to take over. I do not see any bugs when you look up close either. Any advice would be very appreciated.

(Answer)

There is no easy answer to your lawn problems. From the information you provide, you seem to be doing everything right, not only with watering, but also by adding topsoil, aerating, etc..  I suggest that you show photos of the lawn to an expert for their opinion.  Take a look at Landscape Ontario’s Find a Company click on “lawn care” and you will find contact information for experts in your area.

It is very odd that although other areas of your lawn have been able to recover from this hot, dry summer weather we have had in the GTA, the area you show in the photo continues to die off.  Chinch bugs and grubs come to mind as possible pests, but you should have been able to see the little critters when you pull back a patch of the grass and look underneath.

Ontario’s Ministry of Agriculture, Food & Rural Affairs has a helpful factsheet, Is a Brown Lawn a Dead Lawn?  that discusses dormancy during dry periods, which may be an issue here. It also mentions that if the lawn is damaged by drought or chinch bugs, overseeding in the autumn should enable it to recover.

And just in case….the federal government’s Chinch bugs has helpful information about chinch bugs.

The timing of aeration, overseeding, fertilizing and watering is also important.  To keep your lawn healthy,

  • Aerate and add seed to the grass in the autumn when the weather is cooler and rain is more likely
  • Fertilize the lawn in the spring and fall, not during drought when the grass is stressed
  • Try to water in the early morning so that the grass will be less susceptible to fungal diseases. Water deeply in order to ensure the roots are well-nourished.  You mention that your soil is sandy; sand does not retain moisture for long, so the grass roots may be more thirsty than they would if the soil were clay.  However, as the soil in the rest of your yard is also sandy, we would expect that your entire lawn would be brown!
  • In the summer, it’s best to mow the grass at a height of around 6 cm (3 inches), as the taller grass helps to decrease the water lost via evaporation.

All the best in finding out what’s up with your lawn!  Please write us again with an update.