Did you know that grass root systems come out of winter dormancy well before the grass greens up? The root systems actually start putting on root growth before top growth to improve health and stress recovery.
You can usually tell that grasses are starting to come out of dormancy at the root level as soil temps get into the mid 40’s for cool season grasses and in the low 50’s for warm season grasses. Another tell-tale sign is that your lawn just barely starts greening up all on it’s own. A 15% green-up paired with the aforementioned soil temps is your general queue to feed the lawn as I describe below.
You can see this video for more on when grass starts greening up based on geographic location and grass type.
Now let’s talk about the feeding for this time of year.
How To Fertilize Your Lawn In the Early Spring – It’s First Feeding Of The Year
For Spring feeding you want to encourage green up, improve soil health, and stimulate robust root development. You do not want to push top-growth of your lawn however so you shouldn’t add nitrogen until time of year and soil temps are causing your grass to actually start growing naturally.
On the low end of the spectrum, for northern grass types like Ryes, Fescues, or KBGs this could be when soil temps are in the mid 40’s on average and also on the low end for southern grass types like Bermudas, Zoysias, St. Augs, and others this might be when the soil temps are in the low to mid-50s.
Green up fertilizers include products that include micronutrients like Magnesium, Manganese, and Iron, while root development fertilizers include products that contain Phosphorus and Potassium however it’s not usually wise to apply Phosphorus so early in the season – those are best applied later in the season – and an overabundance of Potassium in the lawn has a negative correlation with root uptake of the micronutrients needed for green up so that should be applied later in the season as well.
Remember, most products are generally fine to apply to a lawn in low application rates when the soil is well thawed from the surface level all the way down through the root zone of your grass (the fist 4-5 inches) and when your grass type is starting to exit winter dormancy in the root zone.
Even if your grass hasn’t significantly started growing new leaf tissue yet its root systems will start growing under ground in cold climates when soil temps are in the mid 40s and southern grasses roots will have woken up when soil temps are close to 50-55. These temps indicate that the roots can uptake some nutrients so long as they aren’t over-applied.
We don’t want to push leaf growth however so instead of fertilizing with any NPK in the early Spring we can (or should) only apply the other misc products that stimulate root development without actually feeding the lawn and/or pushing growth.
Products that stimulate root development typically include ingredients like humic acids, which aide in nutrient uptake in the root zone while also improve the soil structure. Humic acid will not feed the lawn at all and it won’t stimulating top growth but it will make the soil healthier and allow your grass plants to uptake nutrients efficiently when they are ready to do so.
To further support root systems on top of adding humic acid to the lawn we can add other specialty products that contain sea kelp, seaweed, or straight cytokinins (which are usually found in sea kelp and seaweed extracts).
These products serve as hormonal stimulants to your grass root structure. As it is starting to grow this type of feeding can help those root systems grow more vigorously better preparing the lawn to start putting on top growth later in the Spring. These hormonal responses in your grass may also help end winter dormancy a touch earlier than normal just the same way that they can help stave off or postpone winter dormancy by a little bit in the late Fall.
You can learn more about the products I use and recommend on my recommended product page right here.
If you plan on fertilizing the root zone of your grass and/or to encourage green up without top growth then the products best applied will be liquids. Many liquids are absorbed in part through the foliar leaf structure if it is not dead or dormant and the liquid products can get to the root zone much easier than granular products can.
Granular fertilizers are better used later in the Spring as soil temps are approaching or above 50 because they need to be watered in and many need to be broken down by soil microbes to become plant available; this isn’t usually possible in March or early April unless you live in a very warm southern area of the country.
It may also be tempting to apply products to the lawn that feed the microbial life. Molasses is a common ingredient used to feed microbes and there are other options out there too that are specifically used for supporting heathy ecosystems in your soil but they shouldn’t be applied to soil that is colder than 50 degrees because most soil life is dormant as temperatures drop below the 50-55 degree range.
In my opinion the first lawn application of the year should be done for cold season lawns when you start seeing signs of the grass emerging from dormancy. This may be when you have between 5-15 percent green up already and average soil temps are consistently in the 42-45 degree zone. For warm season grasses you may be better served waiting for soil temps to get above 50 before doing any of these things.
In my lawn I’ll be kicking the season off by applying a half rate of liquid micro-nutrients only along with a full liquid rate of humic acid – at the same time. The humic will aid the grass-plants that are emerging from dormancy in their root systems to uptake the micros more efficiently and start forming chlorophyll… and then the following week (assuming weather allows) I will follow up with a half rate application of straight liquid chelated iron mixed with a half rate application of CytoGro, my source for cytokinins, the hormone that aids in limiting dormancy and the active ingredient that stimulates robust root development from the nutrients already inside the plant.
This 1-2 punch will help to quickly bring your lawn out of dormancy and green up before everyone else on your bock and it will also stimulate early and robust root development well before everyone else starts thinking about boosting the root system in preparation for the high heat of summer.
You can price out CytoGro over on Yard Mastery right here.
Alternatively you can price out N-EXT’s RGS product which also contains Sea Kelp Extract, a source for cytokinins, also over on Yard Mastery right here.
For warm season grasses your most vigorous grass growth will come in the Summer anyway so this plan should be effective for you guys because it builds the health of the soil, greens things up, and pushes new roots during the time of year that your lawn doesn’t really want to grow quickly anyway.
Remember, we don’t want to add NPK, all of these nutrients should be in the grass plants already as storage from last fall. When the plants are ready to grow then they will grow and then we can start thinking about applying NPK fertilizers and feeding the microbes in the soil during the mid Spring after nature shows itself off in early April.
If you’ve read this far then make sure to see the next post in this series, my full Spring fertilization schedule, or my full Spring lawn care guide which covers all of the things we should do to the lawn in the Spring to let it perform it’s best. You can see the Spring lawn care guide right here.
Thanks for reading and I hope all of this helps you out in your lawn!