Key Questions to Ask When Ordering NPK 32-0-4

10 Mar.,2025

 

What fertilizer should I buy? How to read the LABEL

   'What fertilzer should I buy?'

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We get this question all the time.  The truth is, there are a lot of fertilizers to choose from, and many of them are good.  By understanding the basics of a fertilzer label, you have a better chance of finding a quality product.

Guaranteed Analysis: N-P-K

Maybe someone has told you to buy '20-10-10' or '12-12-12'.  Do you know what this means?  Every bag of fertilzer has a label with a Guaranteed Analysis, in the form of three numbers seperated by dashes.  The numbers represent the percentage (in order) of nitrogen (N), phosphorus (P), and potassium (K) contained in that product.  Therefore a bag of 20-10-10 contains 20% N, 10% P, and 10% K.  These three nutrients are the most essential nutrients for turfgrass health.

The above label is for a 12-12-12, or 'triple twelve' fertilizer.  This is a balanced fertilizer, providing equal amounts of N, P, and K.  This particular fertilizer also provides 15% Sulfur (S), which is considered a secondary nutrient in turf health.  A well balanced fertilizer is recommended at the time of sodding or seeding to ensure that your new plants get all three essential nutrients.

Slow-Release Nitrogen

Nitrogen is the most important component of a turf fertilizer, and is most responsible for green color and shoot (blade) growth.  Nitrogen gives you a lot of 'show'.  It greens and grows turf in a hurry.  However, it also goes away quickly.  You might see 3 to 4 weeks of fast growth, then it quits, and your grass loses color.

This problem can be mitigated by using slow-release nitrogen fertilizers.  Rather than a quick feed all at once, the nitrogen is released over time.  Some high quality nitrogen sources can continue to feed for an entire growing season.

This label is quite different from the first one we looked at.  The Guaranteed Analysis is 32-0-4.  This fertilizer provides 32% N, no P, and only 4% K.  In other words, this fertilizer is mostly nitrogen, designed to provide a quick response, green color, and shoot growth.

However, notice the last line with the asterisk '* Contains 9% slowly available nitrogen . . . '.  This is good.  It means that 9% of this bag is SLOW RELEASE.  With 32% total N, 9% means that over 1/4 of the nitrogen in this bag is in slow release form.

So, which one should I buy?

Even with some knowledge of the labels, this is still an involved question.  Variables affecting your decision include grass type, time of year, weather, and soil conditions.  Here are a few key tips to remember:

  • Balance ' Try to avoid fertilizers that are mostly nitrogen.  These products can be okay at the right time of year, but can also deprive your grass of the other key nutirents.  You don't have to have perfect balance.  A 20-10-10 analysis is okay for many applications.  Or, take for example, a 23-5-12.  This one is a little heavy in N, but also provides some P and a decent application of K.  This would be a good fertilizer for late season application on Heartland Fescue.
  • Slow-Release ' There are some high quality fertilizers with anywhere from 50% to 100% slowly available nitrogen.  In lawn maintenance, this is very beneficial.  You may pay more per bag, but you should be able to put down fewer applications.  Most organic fertilizers naturally contain slower release sources of N.
  • Time of Year and Grass Type- These go hand-in-hand.  The timing of your fertilizer is almost as important as what is in the bag.  Cool-season grasses should be fed during the spring and fall.  Warm-season grasses should be fed in late spring and summer. For correct timing for your grass type, consult a professional or see the Tips and Guides on our website.

Where do I find high-quality fertilizer?

You can buy good lawn fertilizers in many stores.  If you know how to read a label, you may find adequate products at your local hardware store or even a 'big box' store.  If you are not sure, we recommend going to a local independently owned garden center.  There are also some local wholesale supply houses that sell to the general public.

Frequently Asked Questions About Fertilizing Your Lawn - Scotts

What we're talking about here is lawn fertilizing ' how to fertilize, when to fertilize, how often to fertilize and so much more. Ready to get cracking? After all, that lawn isn't going to feed itself!

Lawn Fertilizer FAQs

What is lawn fertilizer?

Think of lawn fertilizer this way: No matter how many glasses of seltzer you drink, you can't live on it'you need to tuck into a few good meals each day, too. Your lawn is just the same. As much as it needs water, it also needs additional nutrients to survive, and lawn fertilizer supplies those nutrients.

What are the benefits of putting fertilizer on my lawn?

It's about more than just thicker, greener grass that's the envy of the neighborhood (although you'll get that, too). Fertilizer helps your grass by providing nutrients to build deeper roots and thicker, greener blades. It's how you get lush grass that can take a beating from heat, sun and all the foot traffic you can throw at it. And you know those weeds you hate? Since stronger, thicker grass naturally crowds out weeds, they'll stand much less of a chance in a lawn that is well-fed.

How do I choose the right fertilizer for my grass type?

First, determine whether you live in the northern or southern half of the country. That's important because the cool-season grasses that grow in the North have different fertilizer needs than the warm-season grasses found in the South.

Next, you'll need to determine if you have other needs, like insect or weed control. Scotts® has products that address multiple issues at once, so identifying your lawn's needs helps you zero in on the right product.

And finally, choosing the right fertilizer depends upon the time of year you are applying it, as grass has different needs during each season. Visit How to Choose Lawn Products and Spreaders for more info and specific lawn food recommendations, or check out the Scotts Lawn Care Program to get recommendations for your lawn.

How long does it take for lawn fertilizer to work?

You'll start to see results anywhere from 1 to 5 days afterward, depending upon the type of fertilizer you use. And because most Scotts® Lawn Food products have Scotts® All-In-One Particles®, they give your lawn an even distribution of nutrients every time you apply it'helping your grass avoid the feast-or-famine, green-to-brown rollercoaster every couple of weeks that you'd experience with poor quality fertilizers.

What do the letters NPK on the fertilizer bag mean?

Those letters stand for the nutrients nitrogen (N), phosphorus (P) and potassium (K). The numbers you see on the bag (32-0-4, for example) let you know the percentage of the N, P and K (by weight) that's in the bag. Here's why it matters: Nitrogen greens up your grass and helps it grow, phosphorus stimulates root growth and helps seeds sprout, and potassium helps your lawn withstand drought and disease. The highest number for lawn fertilizers will usually be the "N"'after all, growing green grass is the ultimate goal, right?

Lvwang Ecological Fertilizer contains other products and information you need, so please check it out.

How do I kill weeds while fertilizing my lawn?

Simply choose a fertilizer with weed control, sometimes referred to as a weed-and-feed. Scotts® Turf Builder® Weed & Feed, for example, kills over 50 types of weeds (including dandelion and clover) while feeding your lawn. If you live in the North, another option is to use Scotts® Turf Builder® Triple Action, which both kills and prevents weeds while nourishing your grass. In the South, Scotts® Turf Builder® Southern Triple Action is the product to turn to for weeding, feeding and all-important fire ant control. As you can see, there's no need to apply two or three products to cover all of your lawn's needs'and that means less work for you.

When and how often should I fertilize my lawn?

This one's easy ' fertilize four times a year, in early spring, late spring, summer, and fall. Have a hard time remembering? Just download the My Lawn App to help you keep track.

For more information, check out When to Fertilize for a Greener Lawn.

What is the best way to apply fertilizer?

It's pretty simple! Just follow these steps: 

  1. Water your lawn a few days before fertilizing so your soil is ready to accept the fertilizer.
  2. Following the directions on the bag, pour the fertilizer into your spreader and adjust the spreader settings. You can use a hand-held spreader, like the Scotts® Whirl' Hand-Powered Spreader for a small lawn or a Scotts® Turf Builder® EdgeGuard® DLX Broadcast Spreader for a larger lawn.
  3. Apply the fertilizer beginning with the perimeter of your lawn, then move inward toward the center, walking in your typical mowing pattern. Use straight, slightly overlapping lines to ensure good coverage.
  4. Return any unused product to the bag and store it properly (again, check the bag for instructions).

How do I know which spreader setting to use?

There are several easy ways to help you figure out the right spreader setting. Try one of these:

  • Visit the product detail page for your particular fertilizer on Scotts.com and look for the downloadable label in the "Specs and Details" tab.
  • Use our Spreader Settings tool or read the spreader settings guidelines on the product package.

Is there a best time of day to apply fertilizer?

Late afternoon or early evening (when there's still light, of course) is the best time of day to apply lawn fertilizer. Applying it in the heat of a scorching afternoon can cause the sun's rays to burn your grass'and when your goal is "lush and green," burned grass blades simply won't cut it.

Do I need to mow, rake or aerate my lawn before or after fertilizing it?

Ideally, you should mow and rake before fertilizing so that excess lawn waste is removed and the fertilizer will have an easier time reaching the soil. Aerating your soil before fertilizing can also help; the best times to aerate are when your grass is actively growing, such as in spring or early fall. For more information, check out How to Aerate & Dethatch Your Lawn.

Can I apply fertilizer to a wet lawn?

Most Scotts® fertilizers can be applied to either a wet or dry lawn. If you're applying a weed-and-feed product like Scotts® Turf Builder® Weed & Feed, though, you may need to apply to wet grass to help the particles adhere to the weeds for best results. How to know for sure? Check the package directions!

How long after fertilizing should I wait to water my lawn?

It depends on the fertilizer. Some lawn foods perform better when you water them in right after applying, while others'such as some weed-and-feed products'need to be watered a day or two after fertilizing. It all comes down to this: Check the product directions on the bag'they'll tell you when to water.

Should I apply fertilizer before or after rain?

You'll definitely want to check the weather before you plan to apply fertilizer'if rain is in the forecast, you'll want to wait for another day. Rainfall before you fertilize won't ruin your plans and in some cases may actually help. A light rain after you apply fertilizer won't hurt either, but a downpour could wash the fertilizer away.

When is it too hot or too cold to apply fertilizer to my lawn?

This depends upon whether you have cool-season grass or warm-season grass. The best time to fertilize your lawn is when the grass is actively growing. For cool-season grasses, that's when air temperatures are 60 to 70° F. For warm-season grasses, active growth will usually happen when temperatures are between 75 and 85° F.

If you live in an area where grass goes brown during the summer, you'll want to avoid fertilizing it while it's dormant. As for the deepest winter months, there's no benefit to feeding your lawn at that time of the year in most areas of the country, as the grass is dormant from the cold weather. Keep in mind, too, that you never want to put fertilizer on frozen ground because the grass won't absorb it.

Can I fertilize before or after I seed or lay sod?

First off, fertilizer won't kill your new grass when you follow the directions. It's best to look for a starter fertilizer with a higher ratio of phosphorus than regular fertilizer. We recommend using Scotts® Turf Builder® Starter® Food for New Grass right after seeding or laying sod. Not only will it help your grass grow 35% quicker and 70% thicker than new lawns that haven't been fed, but you can also use it on all grass types.

On the same topic, don't fertilize before seeding or laying sod. You're just making more work for yourself. If you use a weed and feed to kill weeds before starting a new lawn, you typically need to wait at least a month before seeding or laying sod. Double check your product's label for specific instructions.

How long after reseeding or overseeding my lawn should I wait before fertilizing?

Your best bet is to fertilize your newly seeded or overseeded lawn with Scotts® Turf Builder® Starter® Food for New Grass directly after seeding. Then, you need to wait 6 to 8 weeks before fertilizing again. If you get over-eager and think "If a little fertilizer is good, then a lot of fertilizer is better," let us save you from yourself. Over-fertilizing at any time, especially with newly seeded lawns, can actually damage your grass.

How long do I need to keep kids and pets off the lawn after fertilizing?

A good rule of thumb here is to allow 24 hours after rainfall or irrigation has watered in the fertilizer before letting kids or pets play on the lawn. So, for example, if you fertilize on Thursday and water or have rain on Friday, then you can let everyone release all of their pent-up energy out in the yard on Saturday.

Can I use lawn fertilizer in the garden?

While you technically could use lawn fertilizer in the garden, it's not ideal. That's because veggies and flowers have totally different needs from grass. Lawn fertilizer would still feed your garden plants, but they wouldn't achieve maximum growth. Plants fed with lawn fertilizer might grow more leaves at the expense of flowers and fruits since that's what lawn fertilizer is optimized for: growing lush and green.

Another reason to avoid using lawn fertilizer in the garden is that many lawn fertilizers also contain ingredients meant to kill weeds. Guess what happens when you use those in your garden? That's right, both the weeds and the garden plants bite the dust. Your best bet? Keep lawn fertilizer in the lawn.

Not to worry, though. Just like Scotts has your lawn covered, Miracle-Gro has a variety of plant foods designed to help your garden thrive.

Does fertilizer ever expire?

Fertilizer doesn't expire, but we recommend keeping it dry and in an airtight container, and using it up within a year to get the best results. The longer the fertilizer sits unused, the more likely it is to become damp and clumpy, which could make it hard to spread.

Does Scotts offer a money-back guarantee?

Absolutely. Every Scotts® fertilizer carries the Scotts Miracle-Gro No-Quibble Money Back Guarantee': If for any reason you, the end-user consumer, are not satisfied with the performance of your product, we will happily refund the purchase price. Simply send us evidence of purchase and we will mail you a refund check promptly. We believe in our products and want you to have that same confidence.

For more information, please visit NPK 32-0-4.