Hello mmccallister,

Here’s the Michigan‑specific, MSU‑aligned diagnosis of what killed the turf at your vacation property

Most Likely Cause: Winterkill (NOT over‑fertilization or grubs)

Based on your description and Michigan conditions, the pattern you’re seeing is classic winterkill, especially in lawns that:

Are unattended all winter

Experience extended snow cover

Have freeze–thaw cycles

Sit in areas with poor drainage or uneven grade

Your page notes that the lawn was covered in snow when you visited in winter — this is a major risk factor.

Why winterkill fits your symptoms:

Large, irregular dead patches in spring

Turf that is completely dead, not just thin

No signs of grub tunneling or animal digging

Occurs even in lawns that were healthy the previous summer

This is extremely common in Michigan after winters with long snow cover.

Why it’s NOT grubs

Grub damage shows:

Turf that peels up like carpet

Skunks or raccoons are digging

Damage starting in late summer/fall, not suddenly in spring

Your description doesn’t match the symptoms of a grub.

Why it’s NOT over‑fertilization

Scott’s 4‑step program is designed to be safe when applied correctly. Over‑fertilization causes:

Burned, straw‑colored streaks

Damage in patterns, not large random patches

Usually visible immediately, not after winter

Your lawn was healthy all summer, so fertilizer burn is not the cause.

Could it be snow mold?

Pink or gray snow mold can occur under long snow cover, but:

It causes matted, bleached patches, not complete death

Turf usually recovers by late spring

Your page says the grass is dead, not just matted or discolored.

So snow mold alone does not explain the severity.

So what caused the dead patches?

Winterkill, uneven grade, and prolonged snow cover are the most accurate explanations.

Low or uneven areas trap ice and water, suffocating turf roots.

This matches your note that you want the lawn regraded to be flatter, which strongly suggests that drainage issues contributed to the kill.

Is power‑raking + reseeding the right fix?

Yes — but only if the soil grade is corrected first.

Best practice:

Regrade the lawn to eliminate low spots and improve drainage.

Remove dead turf (power‑rake or dethatch).

Add a thin layer of topsoil only where needed to smooth the grade.

Reseed with a Michigan‑appropriate mix (KBG + perennial rye).

Keep the seed moist for 3–4 weeks.

You do not need to replace all the soil unless:

There are construction debris layers

The soil is extremely compacted

You want to raise the grade significantly

Most Michigan winterkill lawns recover fully with regrading + overseeding

I hope this helps!