It’s that time of the year again. Time to prepare our lawns for winter and start hanging our lawn tools in the shed. But where to start and when to end exactly? How can a new homeowner organize an optimal order of operations if they have no prior experience with fall lawn care? Stay tuned.
First, it’s important to know that not all listed operations are applicable to your case, and what is optimal for one person in one area, most likely won’t be optimal for you.
Introduction
Today we have a treat for all fans of autumn lawn care, if they even exist. In all seriousness, it can be quite a pain organizing all of the autumn operations, so we decided to help homeowners out with this neatly organized list.
It’s difficult now but you’ll be thankful that you’ve given yourself an easier time in the future, and a healthier lawn by preparing and strengthening it properly.
Order of operations throughout the fall:
It’s just as important to perform the lawn care operations in the correct order, as it is to perform them to a high quality standard. Picking the right actions themselves while staying in budget can also be tricky.
Here is what to do and what not to do in your fall lawn care activities.
We will go through all the items from this list and explain all the details, and color codings.
Note:
- One square is ~ 7 days. This entire chart can be shifted back and forth (actually, left and right) depending on when exactly autumn starts at your location. What’s important is the order. You could even use it in the southern hemisphere – just replace the month names.
- Seems very complicated, but really, once you’ve done it once, it’s going to be easier every next time.
This article is meant to cover as many cases as possible and to provide a guide on how you can get the most accurate information for your specific case.
Soil Testing – Playing it safe, whenever possible
The biggest reason to put this suggestion on top is that the details of your soil, terrain and climate conditions will inform many other decisions downstream. If you are new to this and you’ve never done a soil test on your property, there are some quick and cheap tests you can perform:
- pH reaction
- CEC (Cation exchange capacity)
- Soil structure (ratio of sand, silt and clay) and identifying the exact class
- Organic matter content
- Water filtration properties
Barring that, you could also ask your neighbor (for free) or get the data from a map if you can get access to one.
Usually, the cheapest way is to just ask someone from the field of soil sciences. Your local irrigation equipment vendors might provide that information or point you in the right direction.
Soil testing need only be done once, really. If you already have some basic information about your soil type, it’s fine to skip this step.
Why test my soil?
First, It might be unnecessary to perform certain more expensive operations if the soil doesn’t have the problems you’re trying to solve.
Second, knowing what’s missing from the soil will help you with prioritizing and targeting operations that will have the most drastic positive (or the most immediate) impact on the health of your lawn.
Third, most of this testing can be done only once, and if there aren’t huge terrain and soil differences between you and your neighbors, you could collaborate and share the findings while splitting the bill.
Fourth, the information gained can also help you better manage your garden or orchard if you have one, or just pick the most appropriate grass seed mix for your soil type and climate.
When to test my soil?
As can be seen in the chart above, soil testing takes position #3 on the list, but that is only because it’s preceded by already active mowing and clipping collecting tasks.
In practice, this is supposed to be the first autumn-specific activity. It’s recommended to collect soil samples around late August or early September. Definitely do this before dethatching.
You really should have the final test results at hand before aeration, and before overseeding.
Early Fall Mowing: Don’t stop cutting until 1 week before first frost
This info is specific to early fall, and the period before overseeding. For late fall mowing, refer to this section.
- Don’t stop: Grass isn’t dormant yet, but growth does slow down.
- Keep your mower blades sharpened up.
- Cut lower but not too low. Don’t “scalp”.
- Northern Climate zones (cool-season grasses) [summer cut is 1.5-2.5 in, but now it’s 4-6 in]
- Southern climates (warm season grasses) [ summer cut is 2.5-3 in, but now it’s 6-8]
- High Grass during winter creates good conditions for small rodents to settle or make paths.
Be polite to your lawn and collect the grass clippings after mowing.
Early Fall: Cleanup of fallen leaves and grass cuttings
You don’t have to be a perfectionist about this but make sure your lawn doesn’t get turned into a compost field.
With more moisture and less sunlight there are dangers of mildew and fungal diseases developing on grass that is covered with dead leaves of old cuttings. Rake those up and dispose properly or compost.
Early Fall: Dethatching
Thatch over 1-inch thick makes a good home and environment for both root feeding insects and pathogens that cause plant diseases.
Context matters when it comes to thatch:
Note that the same thatch that makes problems for healthy lawns is desirable in your garden or orchard, especially in warmer climates because that layer of dead grass keeps the soil moisture in the ground. In this case we’d call it “mulch” and sing its praise all day long, listing many benefits to our cultivated plants.
Dead organic matter on lawns is a completely different scenario, and is unwelcome in most cases.
When to remove thatch
Dethatching at the same time as aeration will help with all of the extra water that is expected in the fall but do be careful/mindful of the rain season. These operations are done when the soil is near field capacity or lower than that but not completely dry.
How grass type dictates the need for dethatching
Bluegrass absolutely needs dethatching. Fall is better to do this since doing it in the spring will also benefit the fast growing weeds by giving them space and good growth conditions.
Fescue and perennial ryegrass (bunch forming grasses) don’t form an obstructional layer of thatch so they rarely if ever need dethatching. Core aeration in the fall is still desirable.
Early Fall: Aerating
If your soil tests show that the composition is leaning towards silty or sandy, then there’s no need to aerate as often.
The compact clay-heavy soils are going to need aeration every 2 years at least. One other thing that helps prevent water retention on the surface is organic content and humus levels in the top 10-20 cm of the topsoil.
Aerators are expensive so it’s better to rent them every couple of years than have them sitting around gathering dust 99% of the time.
In theory, you should finish aeration by autumn (mid-october) so the soil has time to settle back before winter. In practice, it’s better to do it early so it can be attached to / separated from other operations (depending on the operation). Ideally, it should be your goal to finish dethatching at any time during September.
Types of aeration tools: solid-tine Vs hollow-tine aerators
Ironically, compact soils are more sensitive to aeration techniques/methods: using solid tines on compact soils (without a vibration mechanism) can make them even more compacted.
Always try to use hollow-tine aerators, while solid-tine aerators can be used on more loose soils (which ironically, don’t even need that much aeration work). Make sure that the hollow tips are empty and clean before using an aerator, especially if it’s rented.
After aerating it’d be good to perform overseeding. Ideally, up to 7 days after aeration & dethatching.
Early to Mid-Fall: Overseeding
Do this after dethatching. The order should be: Dethatch > Aereate > Overseed.
Some more caveats to keep in mind:
- Ideally, you would work backwards from your expected first frost date, ensuring you have at least 6-8 weeks before frost for new grass to establish.
- However, the most critical factor is soil temperature, not just frost dates. For good seed germination, you want soil temperatures to still be around 50-65°F (10-18°C). Soil temp should be the primary trigger for starting the sequence, rather than just the calendar date.
- Day length also matters – grass needs enough daylight hours to establish before winter, regardless of frost dates.
- Different grasses will germinate and grow at different rates. Perennial ryegrass will be ready for full height mowing within 12 days, while bluegrass seeds are much lazier and you’ll have to wait ~20 days to see the new growth.
Spreading a thin layer of compost or topsoil after overseeding would ideally be the next step, and ultimately seal the deal with 1 good round of watering to wash the seeds into crevices and slits in the soil. Followup watering will be a bit different. More on that later.
Applying compost tea is recommended by many experts and homeowners. Regarding winterizers, that is a late-fall operation we explain later in the article.
Lawn irrigation during autumn
If your falls are very rainy, it’s probably OK to skip irrigation but be advised that recovering the plants after extreme heat is going to give them a great head-start in the spring and better survivability during the winter.
A mild drizzle isn’t going to help the recovery much.
Heavy rain is a different story. Skip watering for 7 days after heavy rains.
10-20mm (~ ½ in) is a good weekly dose of water for autumn while waiting (expecting) supplementation from rainfall.
Watering after overseeding
Watering after overseeding should be lighter and more frequent for 1-2 weeks, and then gradually decreasing frequency while increasing watering intensity as the seeds settle and germinate.
In the table shown above, this is shown as red color in the row referring to irrigation.
When to stop watering your lawn in the fall?
End irrigation when consistent frost begins. For USDA zones 5-6, (like areas around Chicago IL, or Denver, CO) this is usually late October/early November.
Late Fall: Mowing, Cutting & Leaf Cleanup
Mowing in late fall – first, take a break
If you opt out for the highly recommended overseeding task, this is how to handle mowing after you’re done spreading the seed mix. To explain the green-colored operations from the chart above:
- For 1-2 weeks after overseeding, mowing should be paused. By now, you will have already shortened your mowing height so this would allow for a 2 week break without the grass going too wild on growth.
- This is required in order to allow the seeds to start germinating undisturbed
- As you’ve already learned, at the same time, irrigation intensity will be reduced but frequency increased.
On the chart you’ll notice that green colored operations extend for 4 weeks. This is just a suggested range or time frame in which to do it. Overseed early – pause mowing early. Overseed later – pause mowing later. One follows the other, but you have a choice of doing it earlier or later. Simple.
After waiting for 2 weeks, start mowing again and keep mowing it short, but gradually increase the height to follow the growth of new grass (which you don’t want to cut).
Late Fall Fertilizers: What Winterizer To Apply
You’ve probably applied some compost already mixed with soil after overseeding, but that was supposedly a thin layer just to help cover the seeds. Now it’s time to think about actually feeding the plants.
Aim for a winterizer that is medium-low in Nitrogen (<20), near-zero Phosphorus, and higher in Potassium (10 or more). For example: 18-0-12
Potassium is the key element in making plants resistant to freezing.
- Southern climates: apply winterizer in early fall,
- Northern climates: apply it in mid-late fall
Some winterizer brands include weed-killer chemicals in them. This would probably be a good time to apply it since it’s best not to put those chemicals on the lawn next year in the spring/summer when you want to actually spend time rolling around on your perfect grass blanket.
Unwanted Winterizer Combinations
The reason behind low N is that we’ve gotten some fresh seeds growing and we don’t want too much nitrogen, but we do want them to uptake the potassium.
Grass reactions (resistance) to nitrogen burn differs a lot depending on the grass type:
- Centipede grass is not resistant to N at all
- Bermuda, Zoysia, Tall Fescue: all of them can handle medium N, but it can be harmful in late fall/winter.
- Tall Fescue can handle high N in early or late fall, but it’s still not recommended.
Slow-release N-fertilizers (granulated) would be the only case where you have a guarantee that high-N fertilizers wouldn’t damage your lawn.
Late Fall: Leaf Cleanup
Cleaning up leaves if you have trees around is important for multiple reasons, but the main one is that leaves are quite large and cover newly germinated seeds from getting sunlight in months when there’s already a light deficit.
Leaves also make for a good compost if properly stored and processed. As they fall from the trees, though, they’re just a nuisance that creates a good environment for mildew.
Apart from that, you’re probably going to be picking them up along with the grass clippings, but when it comes to leaf collection, don’t take a break. Just collect them regularly and you won’t have problems.
Conclusion? No, Bonus Content!
Now it’s time to start taking “before” photos so that you can show off your cozy new lawn in a compilation of before/after photos.
But before we send you off, here are a couple of concrete examples of how you can apply the information above and make some necessary adjustments.
To this end, we picked 2 different scenarios, and explained how each scenario “interacts” with the suggestions from the article. so let’s adjust the timing and approach for both scenarios:
PORTLAND, OR (Bluegrass-dominated, Clay Soil):
- First frost: typically late November
- Higher rainfall, milder temperatures
- Clay soil retains moisture longer
Adjusted sequence for Portland OR:
- Soil Testing: Early-Mid September
- Clay soils often have drainage issues, so testing is crucial
- De-thatching: Mid September
- More critical in the Pacific Northwest due to moisture encouraging thatch
- Must be aggressive due to bluegrass’s thatch-forming tendency
- Aeration: Late September
- Very important due to clay soil slow water infiltration rate
- Consider double-pass aeration, nothing is preventing you from just doubling up
- Wait for first fall rains to soften soil – important for clay-heavy soils if you aerate manually
- Compost/Dirt: Right after aeration
- Add more sand-heavy mix to improve drainage
- Overseeding: Late September to early October
- Bluegrass takes longer to germinate
- It has to still be warm enough, but with some natural rainfall
- Earlier than East Coast timing due to milder winters
- Irrigation:
- Less supplemental irrigation needed
- Focus on morning watering to prevent fungal issues
- Monitor carefully due to clay’s tendency to stay wet!
AUSTIN, TX (Fescue-dominant, Silty Soil):
- First frost: typically late December/early January
- Hot, dry falls
- Well-draining soil
Adjusted sequence:
- Soil Testing: Late September
- Focus on nutrient retention in porous soil
- De-thatching: Early October
- Less aggressive, due to soil type and dominant grass type
- Wait for temperatures to moderate
- Aeration: Mid October
- Single pass sufficient, maybe even redundant
- Soil structure allows easier aeration
- Compost/Dirt: After aeration
- Use moisture-retaining amendments
- Apply a bit thicker layer to help with moisture retention
- Overseeding: Mid-Late October
- Fescue germinates faster
- Wait for consistent temps below 85°F
- Can extend into early November
- Irrigation:
- More frequent watering needed
- Focus on deep watering to establish deep roots
- Continue longer into season due to extended growing period
Key Differences:
Portland timing is earlier overall due to:
- Earlier fall rains
- Slower bluegrass establishment
- More moisture management needed
Austin timing is later due to:
- Need to wait for heat to subside
- Faster fescue establishment
- Extended growing season
In both cases, leaf cleanup and mowing continue through the growing season, but:
- Portland: More frequent leaf cleanup needed due to bigger leaf drop
- Austin: Can often mulch leaves into lawn due to extended decomposition season
Conclusion, finally.
We hope you enjoyed this guide. To wrap up, we will include a list of good resources related to the topics covered in this article: