Grass Problem

(Question)

Hello,

I live in East York, Toronto.

Over the past 3 years, I’ve had a lot of difficulty with the lawn in my small back yard. It used to be lush and green.

For some reason, despite annual early spring overseeding and triple mix soil, fertilizer, cinch bug treatment (although I never saw any cinch bugs), adequate water, etc., the grass always starts out promising with new growth and then decides to terminate around the end of May.

This past spring I added a second batch of lawn seed and topsoil in early June as the first application in May didn’t seem to work. New growth started again, only to die.

I don’t want to spend any more time and money on the lawn until I understand what’s killing it, but I really don’t know what to try.

Thank you in advance for any assistance you can provide.

Regards

 

 

(Answer)

Thank you for contacting the Toronto Master Gardeners about your lawn issue.

You have certainly followed many of the correct cultural practices  to encourage your lawn growth, but to no avail, it seems.

Many factors could contribute to a patchy lawn such as compacted soil, competition from  tree roots, incorrect lawn seeds for the site, dull blades on the lawn mower, hand watering among others.  If none of these factors apply to your lawn you may have a disease called Summer Patch, caused by the fungus Magnaporthe poae.  It appears in the early spring but you do not see the evidence until May through September, after a warm spell followed by rain.  This fungus invades the roots, kills them and subsequently you have dead grass.

The best approach would be to encourage strong root growth by increasing aeration of the soil, applying a fertilizer that encourages root growth, raising the height of your lawnmower blades and watering deeply so that the roots are not close to the surface.

An alternative approach would be to remove your lawn and expand your flower border.  I see from your photo that you have a beautiful border around your lawn so you are obviously an experienced avid gardener.

I am including links to a number of websites you might want to check out.

Good luck.

http://plantscience.psu.edu/research/centers/turf/extension/factsheets/managing-diseases/summer-patch

http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/diseases/fungal-spots/necrotic-ringspot.aspx

http://www.gertens.com/learn/Lawn-Care/summer-patch.htm