Should I Overseed Before Winter?

I installed hydroseed at the end of July 2024 and it’s grown in beautifully, but I’m wondering if I should consider overseeding before winter to give my lawn a better chance come spring, especially against weeds.

I’m located in Newfoundland, Canada, which has a cool climate. Currently, we’re experiencing very wet weather, and night temperatures are around 7 degrees Celsius.

Attached is a photo taken around 9 weeks post-seeding on September 29. I’ve been mowing once a week until recently, using mulching blades and leaving the clippings.

No, it would be a waste of seed.

Dallas said:
No, it would be a waste of seed.

Seer.

In Canada, your chance to overseed has LONG passed. Anything that may take won’t be strong enough to survive winter since it won’t have rooted deeply enough.

The window has closed for overseeding. Shoots will be too tender and won’t have enough time to harden before winter sets in.

Your lawn is what it is at this point. If you want to do some pre-emergent treatment, that’s fine, but don’t push for new growth right now.

@Blue
True. You could try dormant seeding, but I’ve never had the guts to try it. It doesn’t seem as effective as regular seeding. But it is an option. If the weather doesn’t cooperate, you risk a lower germination rate.

I would overseed your yard.

I thought about this last weekend. The likelihood of frost killing it off increases daily. My area (Illinois) looked frost-free, and the tree leaves aren’t even turning yet, but things don’t go from ‘all good’ to ‘bad’ overnight. It changes gradually until frost hits.

I put mine down because I had it on hand and the neighbor’s yard guy offered to dethatch and aerate cheaply (my front yard is small). I felt it was about 50/50 on whether it would work. Now I have a frost warning for tonight, so maybe it won’t work out, but we’ll see.

You could dormant seed, but I’m more inclined to focus on having a strong pre-emergent plan for spring to keep weeds at bay. Then plan your overseed in fall 2025.

WARNING: The window for SAFE seeding in all but the southernmost cool season zones (SW U.S.) has now closed. The next recommended option is dormant seeding when soil temps are too low for grass seed to germinate (under 50F/10C but before the ground is frozen).

Seer is for AC. You’ll need a furnace if you want that overseed to grow.

Blair said:
Seer is for AC. You’ll need a furnace if you want that overseed to grow.

Hydrothermal dirt works pretty well. If you don’t want to spend the money, you can always throw some hot hands in your seed mix and then compact the grass during cold spells.

I usually hire an overseed service for that.

Here in the frozen north, it’s too late. Where are you? Who knows?

You can always overseed. Overseeding is another story… most likely it won’t survive.