Here’s your Spring Lawn Care Guide!
We’re going to start with a summary and then in a few minutes we’re going to go into greater detail. Watch the summary and then refer back to the detail section as much as you like.
Before winter ends and while your grass is still dormant you need to resist the urge to fertilize, dethatch, or apply-pre-emergents. Wait until your lawn starts waking up and wait until soil temps start creeping towards 50 before you apply weed preventers. There are caveats to all of this however and I’ll cover many of them further down this page.
As winter is ending you’ll want to coax your lawn back to life again by raking it to get grass blades standing upright. Mechanically aerating it and watering it deeply (not rain), you’ll then apply humic acids, micro-nutrients, and liquid iron.
This will get the grass started so take your time to put the sharpest blade you possibly can on your mower so that you are ready to use it when the grass starts growing.
Apply weed prevention product of choice then set the sprinkler schedule to very deeply water once a week but no more.
Start mowing twice a week and then apply slow-release organic fertilizer in addition to a liquid aeration product to push balanced growth through the Spring and stimulate microbial life in the soil.
You can manually or mechanically dethatch a lawn that has a problem at this time after regular growth has commenced.
Later in the Spring we’ll start a liquid thatch application schedule after soil temps are above 55-60 (when microbial life gets active) and then apply more late Spring fert (no phosphorus and heavy potassium) along with grub preventative as Spring comes to an end.
By late May or early June your mowing height may be raised slightly to provide more soil shade for the summer. I also like to start applying root growth stimulants in mid to late Spring such as Sea Kelp extract to push stronger root systems prior to summer heat extremes.
Before we get further into the article I want to give you the option of watching the video version of this post right here:
Now with all that out of the way; let’s talk about these things in greater detail so you can understand the what and why and when something may not apply to your specific situation.
1. Spring Lawn Fertilization Schedule
2. Can You Overseed A Lawn In Spring
3. When To Water A Spring Lawn
4. Should You Dethatch Every Spring?
5. When To Fertilize A Spring Lawn
6. Are Spring Pre-Emergents Nessesary
7. When To Aerate In The Spring
8. How Early Do You Mow The Lawn In The Spring
Let’s go though things in the order that you’ll likely be doing any or all of these lawn chores.
1. Wake The Lawn Up
I like to wake the lawn up from winter by doing a light raking to the lawn and then running the lawn mower over the lawn on a lower setting than normal to cut off some of the brown tips from the grass from the cold winter weather.
After cutting things down a notch just before the grass starts greening itself up naturally I like to take a manual or mechanical core aerator over the lawn. The manual aerators take a lot of time to get through a lawn so plan accordingly. I’ve demonstrated that it takes me approximately 13 minutes to do 30 square feet of lawn space which would be just shy of 45 minutes for 100 or 450 minutes for 1000 square feet.
The aeration is important because as mid-February rolls around sunlight levels are back to what they were in late October – they should be plenty high enough to generate quality photosynthesis, the aeration allows warmer air to enter the sub-soil layers of the lawn and warm it all up a bit faster than it would otherwise.
Once the lawn has been aerated then you can easily water it with irrigation water or with room temperature tap water to get the temperature of the soil climbing even faster. If you can get soil temps into the 40’s for cool season grasses or the 50’s for warm season grasses then the root systems for those grass types will slowly start to come out of winter dormancy and want to wake up.
You can usually visually see the difference in the grass. It will be slightly more perky and will be slightly more green. At this time I like to apply a light dose of micronutrients to the lawn in tandem with humic acid. The micros should contain some manganese and magnesium for improving the plants photosynthesis process and they should not contain any of the macro nutrients, NPK as we don’t need to push top growth, root growth, or overload the plant with Potassium so early in the season.
After five days to a week the root system should have absorbed a light feeding of these products and should then be ready for a light application of liquid iron, a nutrient usually found in soil but unavailable to the grass in large quantities. The iron will be absorbed by the plant foliage and will allow for greater chlorophyll production for a faster and more noticeable green-up ahead of the natural schedule for your grass type.
In my lawn I then wait a week to 10-days before starting to mow the grass regularly with a freshly sharpened blade. If you do these things then chances are very good that your grass will be green and growing before just about anyone else in your town or neighborhood.
The products I use include frost blankets to retain heat in the soil overnight. These can be purchased at local garden supply stores. Here however is an option available on Amazon in case you want to price things out or shop online: XXXXX
In my lawn I’ve used the Yard Butler core aerator and Lawn Star liquid Iron both available on Amazon, as well as the N-EXT’s liquid Humic Acid, and Simple Lawn Solutions’s Micro Boost. You can improve the speed at which all of these products work by covering your lawn day and night with a frost blanket which will retain ground heat through the night (even when temps don’t get to freezing levels) but will let sunlight through during the day. Frost blankets typically don’t cost a lot and each package will usually cover a lot of square footage… and they can be used year after year if you take care of them.
This is an example of a good cold cover blanket for the lawn on Amazon: XXXXX
For cold season grasses you can usually get the grass green and growing by the time soil temps hit 45 degrees. I recommend checking soil temps regularly (early morning and late afternoon) with a compost thermometer. I use this one that I bought on Amazon: XXXXX
For warm season grasses Centipede grass will green up at low temps, Zoysia wil green up around 50, and the other grass types like Bermuda, St Augustine, & Bahia will typically come out of dormancy when you can get average soil temps into the mid-50s or higher.
2. Apply Weed Preventers (Pre-Emergents)
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4. Thatch Removal
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5. Grub Prevention
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6. Summer Prep
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Here’s Your Spring Summary In Greater Detail (Overview)
- Don’t fertilize, dethatch, or put pre-emergents on the lawn in the winter. You need to wait until nature starts waking things up.
- Once soil temps are well above freezing and before grass starts growing rake the yard to get grass blades standing more upright. This adds air flow and helps the plant to accelerate the photosynthesis process and green up early.
- Early Spring you aerate, then apply weed preventors, humic acids, micro-nutrients, and liquid iron to wake the lawn up and prevent weed infestations later in the year.
- Take time now to get the sharpest lawn mower blades possible before the grass starts growing. Do it yourself with an angle grinder or take it to a mower repair shop. Sharp blades will help the grass resist browning tips and disease later in the year because they will be cut cleanly.
- After grass starts growing begin mowing it twice a week to train your grass to a desired height. Parts of the lawn will start growing before others, just mow it all regularly and it will all even out as Spring progresses. For your first few cuts make sure to bag the clippings to keep as much soil surface exposed to warmer Spring air and to more sunlight which will both work to warm up the upper soil layer.
- Apply a slow release nitrogen rich organic fertilizer such as Milorganite) after the grass has been growing for a few weeks to slowly feed it over the next 8-12 weeks.
- If your lawn has thatch buildup this is the time to run a mechanical or manual dethatching machine or rake over it.
- Set your Sprinklers to run once a week per zone for long enough to apply one inch of water to the area. As summer approaches the duration of this watering session will increase to 1.5 inches per zone due to heat and increased evaporation.
- Continue to mow two times per week all Spring never letting the grass get over-grown and never cutting too much off at any one time.
Pre-Spring (AKA Winter)
During the winter while your lawn is dormant don’t fertilize, dethatch, or put down pre-emergents on the lawn – your lawn isn’t ready for these things unless you live in a very warm southern or coastal climate where your grass never goes dormant.
If your grass is growing in January and February then applying these products may be reasonable. For the majority of the country however most of these action steps can damage the lawn and stunt it’s emergence from winter if done before the lawn comes out of dormancy.
At the end of winter just before grass emerges from dormancy you can and should manually or mechanically aerate the lawn assuming the soil is not frozen in the northern climates. This allows warmer air to travel into the upper inches of top soil warming it up faster while loosening soil for the development of new roots through the growing season.
First Things To Do Early Spring (or Pre-Spring In Warmer Climates)
Soil 40 Degrees – Turn irrigation system on and water the lawn deeply just before the first warm snap of late winter or early spring. This will further help loosen up the soil and continue to warm it up faster due to thermodynamics of heat transfer through water. Water causes the heat transfer effect to speed up approximately 20 times as fast as air transfer alone. A cold Spring rain may be sprinkling your lawn with 35 to 40 degree water but your irrigation system underground can be spraying your lawn with 50-60 degree water which will warm the soil up faster causing your grass to want to wake up a bit earlier.
Soil 43 Degrees – Assuming the soil has not been frozen for a week or two, rake the lawn to fluff up the grass and loosen any debris that has worked its way to the soil surface. Bag the clippings to keep as much soil surface exposed as possible. Then the next day mix a surfactant, liquid humic acid, and liquid micronutrients and apply to soil to stimulate nutrient uptake and wake the plant up as quickly as possible.
Soil 45 degrees – Mix a light dose of liquid chelated iron and apply to dry grass that hasn’t been cut in at least 48 hours and won’t be cut or rained on in another 48 hours. This will stimulate chlorophyll production and photosynthesis helping to turn the lawn green earlier in the season than it would otherwise.
Soil 48 Degrees – Apply a heavy dose of Milorganite to the lawn for slow release of nitrogen, phosphorus, and calcium throughout the spring season. Iron gets applied to with Milo but most isn’t absorbed into the plant.
Soil 48-50 Degrees – apply your early season app of weed preventer / weed pre emergent. This should probably be a half dose of a prodiamine product for a 3-4 month barrier or a pendimethalin product for a 2-3 month barrier for those who either have brand new baby grass or for those people who plan on overseeding earlier in the fall.
- Pendimethalin – (Full Strength Scotts WeedEx App) lasts for 9-13 weeks, or
- Prodiamine – (Low app rate of Anderson’s DG) lasts 14-18 weeks
Alternatively you can apply either of these products if you are getting a late start (mid-spring) or if you simply want to use something organic instead of chemical:
- Corn Gluten Meal – (organic heavy app in late Spring) – lasts for 4-8 additional weeks and includes slow release NPK for steady fert through the summer.
- Dipiophyr – This is an optional mid-spring weed control product that can stop late weeds from germinating and kill off baby weed seedlings that germinated early in the spring. It’s more expensive though. You can get Dimension (even more expensive) or pick up a generic version like this one: Quali-Pro Dithiopyr 40 WSB on Amazon.
Mid-Spring – Mid April to Late May
This is the time to apply products like Sea Kelp for the purpose of stimulating new and deeper root growth before the heat of the summer arrives.
This is also the time to start a 3-4 week liquid thatch removal regimen… even if you don’t have a thatch problem because the program will build soil microbial health even if you don’t have excessive thatch build up.
Late Spring – End of May to Early June
- Apply a grub worm preventative like Scotts GrubEx. This will prevent grub damage to grass root systems later in the summer and early fall and will discourage burrowing animals such as moles who sometimes enter yard space to eat the grubs living under the soil surface.
- Begin cutting your lawn slightly taller and slightly less frequently as temps get close to summer levels. This gives more shade to soil allowing it to manage the heat of summer slightly better.
- This is the time to apply your next fertilizer product, one that contains low-or-no phosphorus but does contain Potassium. I will use a liquid aeration product to deliver ample amounts of potassium and nitrogen rich organic fert to deliver slow and steady nutrients well into the summer but you could use a faster liquid nitrogen product as well to push growth in late Spring before summer heat really takes hold.
Basic Spring Maintenance
Each of these topics will be discussed at length in future posts here on the site and in videos over on the Turf Mechanic YouTube channel.
- What mower should you choose to use, battery mowers emphasized.
- When To Start Mowing The Lawn & At What Height
- When To Fertilize The Lawn In Spring & How Much
- How Often Should You Mow The Grass
- Thoughts On Irrigation Requirements
- Should You Dethatch Your Lawn in Spring (Early vs Late vs Fall)
- Should You Aerate Your Lawn In Spring (Liquid or Mechanical / Early vs Late)
- Should You Overseed In Spring & When
- How To Stimulate Root Growth In Grass For Drought & Heat Resistance In Summer (RGS)
- Late Spring Feeding To Improve Your Lawns Resistance To Disease
- Considerations For Mid-Late Spring Weed Prevention & Early Post Emergents (Dyphomir for Grassy weeds & Tenacity for dandelion and clover, etc )
- Height to cut your lawn as spring advances towards summer
Lead Up to Summer
- Plan for a smaller fertilizer application in late Spring instead of mid summer.
- Begin summer applications of liquid dethatching products before Spring ends – plan on applying every three weeks for optimal soil structural improvements.
- Plan to apply a grub preventative product such as GrubEx in early June before the heat of summer fully sets in.
Setup the viewer to watch the follow-up video on summer lawn care which is yet to be filmed and released.