16-4-8 Fertilizer: Benefits and When and How to Use It

If you’re a homeowner, you probably care about keeping your lawn looking beautiful and emerald green. Or maybe you are a groundskeeper, or a gardener raising a lot of leafy vegetables.

fertilizer truck on pasture
fertilizer truck on pasture

Whatever the case, periodic fertilization of soil is critical to make sure your plants keep getting the nutrients that they need in order to stay healthy and of course maintain that lovely, deep green color.

But fertilization is something of a tricky subject, and analyzing the needs of your plants and then calculating how much of which kind of fertilizer is required can be intimidating.

But you don’t need to worry, because today I’m bringing you a guide that will tell you everything about 16-4-8, one of the best high-nitrogen fertilizers.

It’s ideal for lawn care and for feeding other evergreen plants… Grab your gloves and let’s get going.

What Does 16-4-8 Signify for Fertilizer?

In the case of 16-4-8 and other similarly marked fertilizers, you’re looking at three numbers that signify the chemical composition of the fertilizer by percentage. Sometimes, you will see this abbreviated or indicated as ‘NPK‘.

The first number signifies nitrogen content, with 16 being a fairly high content. Nitrogen is absolutely essential for any kind of plant growth as it helps them to produce chlorophyll and in turn create energy from light.

The second number, 4, indicates the amount of phosphorus, which is essential for root growth and flowering.

The third number, 8 indicates a modest content of potassium, which aids in overall plant health and disease resistance.

Before you raise your hand, yes, you read that right: the last component, potassium, is signified with the letter K.

That’s because the element potassium is denoted as ‘K’ in the periodic table: N for nitrogen, P for phosphorus, and K for potassium. Easy!

What Ingredients are Typically in 16-4-8 Fertilizer?

16-4-8, sometimes called simply “high nitro”, typically contains urea, ammonium nitrate, diammonium phosphate, and potassium sulfate.

Urea is a synthetic form of nitrogen that helps to promote leafy green growth and feed the lawn or garden.

Ammonium Nitrate provides a slow release of nitrogen that’s helpful for sustained plant growth.

Diammonium phosphate serves as a source of phosphorus, while potassium sulfate supplies the necessary amounts of potassium.

Depending on the brand and type, your fertilizer might also contain other additives like humic acid, and seaweed extract that can all help to provide even more benefits to your plants.

Benefits of 16-4-8 Fertilizer

16-4-8 is commonly thought of as an ideal, all-purpose fertilizer specifically for lawn care, grasses, evergreens, and leafy veggies.

Basically, any plant that doesn’t flower or fruit! That’s because these plants need more nitrogen and less phosphorus, and 16-4-8 offers just that…

Its high nitrogen content makes it great for promoting lush, healthy green vegetative growth all around, and dark foliage.

Nitrogen is essential for the production of chlorophyll and helps plants photosynthesize more efficiently, and though all plants require nitrogen, those that do not flower or fruit need larger amounts.

And because 16-4-8 usually contains a slow-release form of nitrogen, it also helps to avoid the ‘nitrogen shock’ that can occur if you use a fertilizer with too much all at once.

This type of fertilizer also offers lasting benefits and can be used in every cycle when fertilization is required.

What Plants are 16-4-8 Fertilizer Best For?

All kinds, but particularly green, leafy plants that don’t flower or fruit, and many grasses. This includes lawns, shrubs, trees, evergreens, ornamental houseplants and even certain bedding plants.

You should typically avoid using it on flowering or fruiting plants however, as these usually need a lower nitrogen fertilizer to ensure the maximum growth potential of their blooms and fruits.

When Should You Use 16-4-8 Fertilizer?

You should apply 16-4-8 to your lawn and other plants in the springtime, to help them get ready for the stress of the summer sun.

It’s also a great choice in the fall, when plants need an extra boost of energy to survive colder temperatures heading into winter.

You can also use 16-4-8 as part of your regular fertilization routine throughout the growing season, depending on your climate and soil type.

When’s the Best Time To Apply 16-4-8?

As usual, try not to apply fertilizer during the hottest and driest part of the day. Early morning or late evening are the best times to apply 16-4-8, as these temperatures will help prevent leaf burn from too much fertilizer.

Also be sure to water your lawn afterwards, if required: this helps to ensure that all of the nutrients are absorbed by your plants’ roots.

It’s especially important to avoid intense sun and higher temps when fertilizing with high-nitro since it is likely to scorch plants if you do!

How Much 16-4-8 Fertilizer Should You Use per Acre?

It varies depending on the product. 16-4-8 has many types, from pellets and granules to powders and liquids. This makes the old standby recommendation of 1lb-per-1000sqft. less than reliable.

The best advice I can give you is to read and follow the manufacturer’s instructions to the letter, and if you have any concerns err on the side of “not enough” rather than “too much”: 16-4-8 can easily fry your grass and other plants if you overdo it!

As always, a soil test is the very best way to determine precisely what your land or plants need.

What’s the Best Method to Apply 16-4-8 Fertilizer?

This too will depend on the product. You may need to use a spreader for granular fertilizers, or the manufacturer might recommend diluting the liquid form in water and spraying it on.

Whatever method you use, be sure to pay close attention to the settings on your applicator: if you have it opened up too liberally, you’ll end up over-applying and that can have disastrous results.

Also make sure you don’t reapply over areas you’ve already covered.

This takes a little experience to get right, both the process and the settings on your tools, but if you need help, the manufacturer can likely assist you. Better some extra homework than crispy plants!

Is 16-4-8 Fertilizer Good for Lawns?

Yes, definitely. Many people consider 16-4-8 the best overall fertilizer for lawns, as it offers a balance of nitrogen, phosphorus, and potassium that helps grass thrive while avoiding overly aggressive growth.

It’s also great for other types of green plants and shrubs, too…

Is 16-4-8 Fertilizer Good for Gardens?

Yes, but with reservations. High-nitro is ideal for any plant that does not fruit or flower, and that means you only want to rely on it to help leafy veggies like kale, spinach, lettuce, cabbage and so on.

Improper or ill-timed application can do more harm than good if you want to bring in a bumper crop of tomatoes or peppers!

What’s the Average Price of 16-4-8 Fertilizer?

Around .16 to .22 cents an ounce, depending on brand and quantity. As normal, bigger buy means a better deal, all things equal.

Where Can You Buy 16-4-8 Fertilizer?

Pretty much everywhere. The popularity of 16-4-8 means it’s available in many big box stores, home centers, nurseries, and online.

It is a perennial choice for lawn care, and is especially common as spring approaches.

What’s the Best 16-4-8 Fertilizer Brand?

There are so many good ones, making any definitive recommendation is bound to start a fight. I like Anderson’s Professional PGF Complete.

It has very small particles that cover better, and dissolve reliably and it also has humic acid that reduces grasses requirements for other micronutrients. Works like a charm and I’ve never had an issue with it.

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