When Should I Fertilize My Lawn In The Spring?

When Should I Fertilize My Lawn In The Spring?

You’re prepared your lawns for winter, waited patiently for warmer temps and longer days to roll around, and now finally jumping into your spring lawn care.  So now you may be asking yourself, “When should I fertilize my lawn in the spring?”

It’s a common question, but for us avid lawn phixers, it may not be as cut and dry. There’s a lot of outstanding questions that we should answer first before we start applying fertilizer to our lawns this spring.

Springtime is when your grass is actively growing, so you’ll want to make sure you account for this in your annual fertilizer schedule. Feeding your lawn in the spring will help developer stronger, deeper roots and promote a green and healthy lawn. Providing enough food for your turf is key to help it get through the hot and stressful summer months.

4 Step Spring Lawn Fertilizer Timing

Step 1: If you are planning a simple 4 Step plan, be it from Jonathan Green or Scott’s, your first application of spring fertilizer will also contain a crabgrass pre-emergent. This means you need to get this applied before your soil temps hit 55 degrees. So target early spring (early April in New England).

Step 2: The second spring application is generally a weed-and-feed fertilizer. Step 2 is applied 6-8 weeks after Step 1. The timing here is around Memorial Day – or approximately two-to-three weeks before the first day of summer.

Early Spring Fertilization

If you skipped a winter fertilizer application and/or did not try nitrogen blitz, then you would also want to apply fertilizer in early spring. This can go down around the same time as your pre-emergent. As always, follow the labels and recommendations on your soil test.

Mid Spring Fertilization

If you applied a last-minute, fast-release fertilizer to over-winter, then you won’t need to apply a nitrogen fertilizer so early on. Your soil should have enough food stored over from winter (October/November) to give it the jump-start it needs in early spring. After you apply your pre-emergent herbicide, you can wait until soil temperatures are warmer – around 55-60 degrees, which roughly correlates to 65-70 degree outside temperatures.

For New England, this first spring fertilizer application can be the end of April. As always, follow the labels and recommendations on your soil test.

Late Spring Fertilization

If you wanted to add a slow release fertilizer to feed your lawn throughout the summer months, shoot a non-burning organic fertilizer such as Milorganite. You do not want to apply any more nitrogen in the hot winter months. This can add more stress to the grass in the heat of summer by trying to force more growth, when in fact the grasses want to slow down.

It’s not uncommon for lawn care nuts with well-irrigated lawns to apply Milorganite on the 4th of July. But sticking to the spring theme – apply prior to the heat and drought summer months. As always, follow the labels and recommendations on your soil test.

Spring Fertilization Applications


  • 4 Step users: Early April
  • No winterizer year prior: Early-Mid April
  • Winter Fertilizer year prior: Late April/Early May
  • 0.75 – 1.0 pounds of Nitrogen oer 1,000 sq. ft.
  • Always conduct a soil test to address micoronutrient and macronutrient deficiencies. Always follow the labels.


  • 4 Step users: Late May
  • Others: Memorial Day
  • 0.75 – 1.0 pounds of Nitrogen oer 1,000 sq. ft. (1.5 – 2.0 lbs. of N year-to-date)
  • Incorporate Humic Acid and micronutrients such as Kelp4Less Green Lawn & Turf or ExtremeBlend. Soil enhancements and amendments will drastically improve the soil quality and promote a healthier and greener lawn.
  • A third application, lower rates, of organic fertilizer is option at the end of spring (mid June)

Spring Fertilization FAQs

When should I fertilize my lawn?

If you skipped a winter fertilizer application and did not nitrogen blitz, then applying an earlier application of nitrogen fertilizer would be a good idea. Most all of the nitrogen gets used up by the end of the growing season in most cool season soils .  When spring rolls around, it’s generally deficient and an earlier application of fertilizer is required. The exception to this is when organic matter levels are very high, and in cases of over-fertilization. But if nitrogen was not applied over-winter, it would most likely not fit into either one of these categories.

Verdict: If you did not apply a winter fertilizer, apply an earlier application of fertilizer such as a Step 1 (Fertilizer + Pre-emergent herbicide combo) as your soil temps approach 55 degrees.

Why should you not apply too early?

If you did apply a late season winter feeding, you can hold off on applying nitrogen fertilizer to your lawn until both soil temperature and outside temps get warmer. For soil temps around 60 degrees, which is when the outside temperatures are approximately 70 degrees. There should be enough nitrogen in the soil to wake your lawn up faster than others who did not winterize. Adding more nitrogen on top of an already-sufficient soil would push the grass hard to grow and cause an excessive amount of top-growth.

Verdict: If you applied a winter fertilizer, wait until temps are consistently warmer. ~55-60 degree soil temps, and ~65-70 outside temps.

When is the best time to fertilize my lawn in the spring?

In New England for example, your peak time frame will be around Memorial Day. Historically, soil temperatures are ~65 degrees which is prime time for cool season grasses. A full application of fertilizer according to the bag rate, which should deliver around 3/4 lbs. of Nitrogen per 1,000 sq. ft. Use our lawn fertilizer calculator to help make the calculations easy.

Verdict: The best time will be the second application towards the end of May when soil temperatures are consistently ~65 degrees.

What is the best way to fertilize lawn in spring?

The most popular choice is by applying a granular fertilizer through a fertilizer spreader. However, there are great liquid options available such as Simple Lawn Solutions, CoRoN, and LawnStar.

What is the best fertilizer to use in the spring?

If your soil test shows low levels of Phosphorus and Potassium, then a starter fertilizer is a great option. Otherwise, a typical Turf Builder or an N-P-K label of 25-0-10 (or similar) with fast-release or quick-release nitrogen. Save the organics and slow-release for warmer months.

Should I apply anything else to my lawn in the spring?

Aside from your standard fertilizer application, we highly recommend soil amendments such as Kelp4Less. As the temperatures get warmer, prepare your own for summer with extra potash, humic acid and sea kelp.

Mid-spring is also time for grub control and lawn fungicide.

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