Hello folks, had some struggles with my lawn over the years (grubs-used nematodes)…overseeded again this year and finally starting to have a healthy lawn. …been cutting it at about 3″…….the other day want for about 1and a half inches and suddenly it seem to have completeley dried up..the whole thing looks like straw..almost dead..what happened?…(by the way we are in Etobicoke..clay soil)
Peter
A grub infestation in one’s lawn can become a problem if it is not treated. You are clearly aware that use of beneficial nematodes may help to solve the grub problem and that overseeding the affected areas is necessary to restore your lawn. The use of nematodes is limited in time, however, as the nematodes die off once there is no longer a food supply of grubs. Also, there are never enough that survive over winter to be effective a second time.
Now you have dealt with the grubs, you have reseeded a lawn that went from healthy to brown and dry very quickly. Your care of a newly seeded lawn has been careful in practice so far. The shift recently of greater heat but lack of rain needed to continue germination and healthy growth took its toll quickly. You need to water a new lawn consistently all season, as some of the seeded grass is annual, used as a temporary soil food to promote healthy growth for the grasses that are perennial seedling (rye, for example). Continue to water frequently, ensuring that the area receives 1 and 1/2 inches per week of water. Watering deeply once a week is best whenever there is not enough rain, and especially for clay soil.
The city of Toronto recommends keeping grass at a height of 3″; perhaps you wanted to cut it short too soon after new growth., and the roots have burned in the extreme heat.
In the fall and spring, add a 2″ layer of compost over the whole lawn to amend that clay soil.
I have included a link to a previously answered question on lawns browning in summer. There are many on our site if you Search ‘Lawns’:
https://www.torontomastergardeners.ca/askagardener/dying-lawn/