What workarounds did people try for "When can I put weed killer down after overseeding?"?

Community members documented 30 workarounds: 1. Waiting 45 to 60 days post germination and/or 2-3 mowings before applying any pre-emergents or herbicides. 2. Choosing between seeding or applying a fall pre-emergent since doing both simultaneously is restricted. 3. Aerating and overseeding in September while waiting to apply pre-emergent in the spring. 4. Waiting for the lime to set in slowly over time 5. Using fast-acting commercial pH adjustment products 6. Picking a few out when bored and letting the grass thicken up to shade them out over time 7. Pulling weeds manually and waiting for the first frost 8. Applying a heavy dose of preemergent the following spring 9. Skipping the application entirely 10. Mowing often to kill weeds and promote grass spreading 11. Applying post-emergent or selective herbicides like 2,4-D or Tenacity 12. Waiting until spring to overseed and treat again 13. Waiting until two weeks after germination to fertilize 14. Using a basic balanced fertilizer like 20-10-10 if grass has already started growing 15. Attempting to manually remove entangled plastic netting with scissors and tweezers 16. Scratched up the soil, threw down more seed, and watered again 17. Ignored the weeds temporarily until the new grass was established before treating them 18. Used Tenacity or mesotrione to prevent weeds from germinating 19. Seeding immediately and planning to overseed or patch bare spots again in the spring 20. Putting down temporary cover crops or rye to prevent mud and erosion before applying better seed later 21. Laying straw netting over newly seeded dirt to prevent washout and protect against animals 22. getting seeds down immediately and dealing with weeds in the spring 23. waiting 4-6 weeks to overseed after weed treatment 24. putting down preemergent in the spring and overseeding next fall 25. Waiting until soil temperatures are consistently below 40 degrees 26. Putting seed down just before the first permanent snowfall of the season that will stick 27. Throwing down half the seed at the beginning of winter and the rest before the last snow to hedge bets 28. Skipping the spring seeding to prioritize weed prevention and waiting until the fall to reseed the lawn. 29. Applying fertilizer at a half-rate to be safe 30. Avoiding fertilizing the newly overseeded areas completely so existing grass doesn't shade out the new growth

When can I put weed killer down after overseeding?

Applying pre-emergents or herbicides too soon after overseeding risks damaging your newly germinated grass, but waiting too long risks losing control of weeds like poa annua, wild violets, clover, and dandelions before winter. This leaves lawn owners struggling to figure out the exact safe timing and product choices for weed control during the fall transition.

Overview

Last updated Oct 31, 2026

People affected20 accounts across 1 forum

Workarounds found30 items attempted

Community agreement71 total upvotes

What people tried

Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.

30 items+ Contribute

Found another way around this?

Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.

1
Waiting 45 to 60 days post germination and/or 2-3 mowings before applying any pre-emergents or herbicides.
Did this help you?
2
Choosing between seeding or applying a fall pre-emergent since doing both simultaneously is restricted.
Did this help you?
3
Aerating and overseeding in September while waiting to apply pre-emergent in the spring.
Did this help you?
4
Waiting for the lime to set in slowly over time
Did this help you?
5
Using fast-acting commercial pH adjustment products
Did this help you?
6
Picking a few out when bored and letting the grass thicken up to shade them out over time
Did this help you?
7
Pulling weeds manually and waiting for the first frost
Did this help you?
8
Applying a heavy dose of preemergent the following spring
Did this help you?
9
Skipping the application entirely
Did this help you?
10
Mowing often to kill weeds and promote grass spreading
Did this help you?
11
Applying post-emergent or selective herbicides like 2,4-D or Tenacity
Did this help you?
12
Waiting until spring to overseed and treat again
Did this help you?
13
Waiting until two weeks after germination to fertilize
Did this help you?
14
Using a basic balanced fertilizer like 20-10-10 if grass has already started growing
Did this help you?
15
Attempting to manually remove entangled plastic netting with scissors and tweezers
Did this help you?
16
Scratched up the soil, threw down more seed, and watered again
Did this help you?
17
Ignored the weeds temporarily until the new grass was established before treating them
Did this help you?
18
Used Tenacity or mesotrione to prevent weeds from germinating
Did this help you?
19
Seeding immediately and planning to overseed or patch bare spots again in the spring
Did this help you?
20
Putting down temporary cover crops or rye to prevent mud and erosion before applying better seed later
Did this help you?
21
Laying straw netting over newly seeded dirt to prevent washout and protect against animals
Did this help you?
22
getting seeds down immediately and dealing with weeds in the spring
Did this help you?
23
waiting 4-6 weeks to overseed after weed treatment
Did this help you?
24
putting down preemergent in the spring and overseeding next fall
Did this help you?
25
Waiting until soil temperatures are consistently below 40 degrees
Did this help you?
26
Putting seed down just before the first permanent snowfall of the season that will stick
Did this help you?
27
Throwing down half the seed at the beginning of winter and the rest before the last snow to hedge bets
Did this help you?
28
Skipping the spring seeding to prioritize weed prevention and waiting until the fall to reseed the lawn.
Did this help you?
29
Applying fertilizer at a half-rate to be safe
Did this help you?
30
Avoiding fertilizing the newly overseeded areas completely so existing grass doesn't shade out the new growth
Did this help you?

Tried another approach not listed above?+ Share your workaround ↑

In their words

Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.

r/lawncare20 people · September 2026 – October 2026

“I got good germination but now all these weeds are coming up… like a LOT of them.”source ↗

“what’s my next plan of action?? Do I just mow? Apply a post emergent???”source ↗

fedswatching2121 · r/lawncare · 13 upvotes

“Had a ton of work done that ended up being more than I expected. Had the back 1/3rd of my rear yard graded.”source ↗

“After the work done this past week, I’m looking at about 6,000sq/ft of new lawn that needs seeding.”source ↗

“I’m thinking I just seed it all and pray something takes, then try to fill as best I can in the spring. What’s your thoughts?”source ↗

CRAKALAKIN213 · r/lawncare · 12 upvotes

“I live in MN and was planning on reseeding over the winter in hopes of the grass growing in the spring. Does anybody have any experience or tips? For example what’s a good temp threshold to hold off until?”source ↗

dukebroncos · r/lawncare · 9 upvotes

“Found these small things growing after reseeding. Should I do something now?”source ↗

“Taking them out seems like a lot of work and I guess it’s too early to do anything else because other seeds are still growing”source ↗

After_Step_8595 · r/lawncare · 5 upvotes

“When should I fertilize and what type should I use? I realize I probably should’ve used starter fertilizer and not the lawn soil initially but it’s too late for that now.”source ↗

Superb-Bandicoot-683 · r/lawncare · 4 upvotes

“One of the 2 spots grew back great, the other seems like the seed barley germinated and instead just got overwhelmed weeds. I think its Oxalis.”source ↗

“I'm at a loss as to what to do now. What should my next steps be? I really wanted a nice full lawn by next spring.”source ↗

a-perfect-sip · r/lawncare · 4 upvotes

“I over seeded my TTTF lawn two weeks ago. I’m looking for advice on timing and type of pre-emergent for mainly poa annua, wild violets, clover and dandelions.”source ↗

nahaka1 · r/lawncare · 3 upvotes

“What’s the best way to fix this? In Colorado for reference. Not sure if I have time before winter?”source ↗

Glum-League-599 · r/lawncare · 3 upvotes

“I basically ran out of time to put down tenacity. is it OK if I do this either today or tomorrow? Should I just skip that part?”source ↗

Foreign-Intern8703 · r/lawncare · 2 upvotes

“My biggest question is whether getting the weeds under control should be the priority, or whether I should prioritize getting the seed down while conditions are still good.”source ↗

scuba_steve410 · r/lawncare · 2 upvotes

“I didn't have much success the first two times I tried to dormant seed right before the first snow of the season.”source ↗

bselite · r/lawncare · 2 upvotes

“I’m going to give it a go this year, I’m in Ky, do you wait until February now? The weather here can be crazy and so unpredictable especially in March”source ↗

Tight_Bug_2848 · r/lawncare · 2 upvotes

“Is there a way to put crabgrass preventer and do some seeding? I'd think the pre-emergent would affect grass seed.”source ↗

timeforpizza1 · r/lawncare · 2 upvotes

“Hi there - planning to put down pre-emergent next spring. I have a TON of crabgrass. My question is, can I aerate and overseed now in September and do the pre-emergent in spring with no issues? The seed will be far enough along the pre-emergent won’t affect it?”source ↗

Top_Chance_3769 · r/lawncare · 1 upvotes

“I was thinking about adding agricultural lime as well, since the solid is basically pure clay. Anything to think about in relation to timing with the seed? Would it be harmful to do it now?”source ↗

bangbangtangwangfang · r/lawncare · 1 upvotes

“After I overseeded I was so spent I totally forgot to use my tenacity.”source ↗

dqontherun · r/lawncare · 1 upvotes

“I accidentally mixed 1 bag of weed n feed along with 3 other bags of starter fertilizer after an over seeding. Am I totally cooked or only partially?”source ↗

Wwg1wga198927 · r/lawncare · 1 upvotes

“The straw & plastic mat has already permanently bonded to the ground. Only way that’s coming out now is if it’s taking that new grass with it.”source ↗

FadedTiger49 · r/lawncare · 1 upvotes

“Kind of what I figured with it being a little late but I also wasn’t sure what the best practices were for dealing with the weeds while also trying to overseed”source ↗

scuba_steve410 · r/lawncare · 1 upvotes

“Only problem is this will be a super El Niño so the weather might not cooperate since you typically want it consistently below 50° to prevent early germination.”source ↗

littlebitlalala · r/lawncare · 1 upvotes

“Overseeded in mid September. Is now a good time to fertilize?”source ↗

“I already read that fall is the best time to fertilize? Should I go for it now?”source ↗

“edit: what about pre-emergant?”source ↗

Standard-Top-5942 · r/lawncare · 1 upvotes

Where this came up

r/lawncare fertilizing gardening home maintenance landscaping lawn care mistakes seasonal maintenance seeding soil management weed control weed management yard maintenance