What Is 10-10-10 Fertilizer, and When Do You Use It

Measure the length of the plant row in your vegetable garden. Unlike lawns and ornamentals, many vegetables are heavy feeders so you don’t have to worry about overfertilization. Always follow the label instructions for amounts and frequency.

A Homeowner’s Guide to Fertilizer

This label, known as the fertilizer grade, is a national standard.

A bag of 10-10-10 fertilizer contains 10 percent nitrogen, 10 percent phosphate and 10 percent potash. Fertilizer grades are made by mixing two or more nutrient sources together to form a blend, that is why they are called “mixed fertilizers.” Blends contain particles of more than one color. Manufacturers produce different grades for the many types of plants.

You can also get fertilizers that contain only one of each of the primary nutrients. Nitrogen sources include ammonium nitrate (33.5-0-0), urea nitrogen (46-0-0), sodium nitrate (16-0-0) and liquid nitrogen (30-0-0). Phosphorus is provided as 0-46-0 and potash as 0-0-60 or 0-0-50.
Calculating Nutrient Content To calculate the pounds of nitrogen in a 50-lb bag of 10-10-10 fertilizer , multiply 50 by 0.10. Do the same for calculating the amounts of phosphate and potash. A 50-lb bag of 10-10-10 contains a total of 15 lbs of nutrients: 5 lbs nitrogen, 5 lbs phosphate and 5 lbs potash. The remaining weight is filler, usually sand or granular limestone.

50-lb. bag of 8-0-24 fertilizer
1. To calculate the pounds of nitrogen: Multiply 50 by .08, which equals 4.
2. To calculate the pounds of phosphate: There is no phosphate in this bag of fertilizer.
3. To calculate the pounds of potash: Multiply 50 by .24, which equals 12.

• 5-10-5
• 5-10-10
• 10-10-10
• 8-0-24
• 6-6-18

What Is 10-10-10 Fertilizer, and When Do You Use It?

Nadia Hassani is a a Penn State Master Gardener with nearly 20 years of experience in landscaping, garden design, and vegetable and fruit gardening.

Mary has been a Master Gardener for 30+ years and a commercial and residential gardener for 50+ years. She is a former Clemson University Extension Agent.

10-10-10 is a fertilizer that contains equal proportions of nitrogen, phosphorous, and potassium. It is used to give plants the main nutrients they need. Because it contains all three macronutrients, it works for most plants, but there are limitations.

Read on to learn about what 10-10-10 fertilizer is, when to use it, when not to use it, and how to apply it.

Key Takeaways

• 10-10-10 is also referred to as a complete balanced fertilizer. It contains three plant macronutrients (nitrogen, phosphorus, and potassium), and is “balanced” because the fertilizer contains the nutrients in an equal percentage of 10%.
• The fertilizer is added to plants that benefit from an overall general fertilizer boost and don’t have a high need for any specific nutrient.
• There is no one-fits-all rule on how much 10-10-10 to apply, as this depends on the plants, the soil quality, the time of application, and other factors. Always check the fertilizer label for application rates.

What Is in 10-10-10 Fertilizer?

10-10-10 is also known as NPK fertilizer because it contains the three macronutrients nitrogen (N), phosphorus (P), and potassium (K) most plants need to thrive. Other micronutrients and ingredients are often added, such as iron for deep greening.

The formula 10-10-10 does not say anything about the sources of those nutrients, which can be synthetic (inorganic) or natural (organic). Read the product label or product sheet for details on the sources of the plant nutrients. Note that organic 10-10-10 fertilizer is not commonly found because organic fertilizers typically contain plant nutrients in lower percentages of concentration.

Liquid vs. Granular 10-10-10 Fertilizer

10-10-10 comes in two different forms, as a liquid fertilizer and as granules. Both forms have their pros and cons.

Liquid 10-10-10 Fertilizer

• Premixed for easy use and convenience
• Watered in with the hose at the time of the application
• Works fast but does not last as long as granular fertilizer
• Has to be applied more often

Granular 10-10-10 Fertilizer

• Needs to be broadcast evenly
• Has to be watered in deeply; failure to do so can burn the plants
• Slow-release and lasts longer than liquid
• Granules can get washed away by rainfall
• Possible health hazard for children and pets until watered into the soil

Which Plants Benefit from 10-10-10 Fertilizer?

10-10-10 is called an all-purpose fertilizer because it can be used on almost any type of outdoor plant, including vegetables, shrubs, trees, flowers, lawns, and houseplants. Generally, it can be applied to any plant that doesn’t need one of the three macronutrients in higher amounts.

Warning

It should be applied with caution to any flowering plants and other plants where too much of one nutrient, usually nitrogen or phosphorus, would be harmful. For example, indiscriminately adding 10-10-10 fertilizer to a flowering shrub or flowers could add excess nitrogen to the soil and cause the plants to produce mostly foliage instead of flowers.

Before You Begin

Before fertilizing your yard with 10-10-10 fertilizer or any fertilizer and applying it regularly during the growing season, it is essential to do a soil test. It does not have to be every year, but it should be done at least every two to three years to provide you with a baseline of your soil quality.

Only a detailed analysis done in a specialized lab can tell you which nutrients should be added to the soil for the types of plants in your landscape. It might turn out that 10-10-10 fertilizer is not the best option for your plants. Overfertilizing can be just as bad as a lack of fertilizer, which can lead to plant wilting, fertilizer burn in lawns, and burned leaves on shrubs, trees, and other ornamentals.

How to Use 10-10-10 Fertilizer

There are generally three ways to use 10-10-10:

By Surface Area (Lawns):

Measure the area to be fertilized, and if in doubt, use less rather than more when applying fertilizer. In addition to measuring the size of your lawn, follow the instructions about when to fertilize depending on the type of grass, and follow the best practices for how to fertilize a lawn.

By Individual Plants

To fertilize a tree, which should be done in the spring, calculate the size of the root zone, also called the drip line. After measuring out the amount of required fertilizer, mark the drip line with a garden hose or spray it with natural grass marking paint and mark another circle 3 to 4 feet away from the trunk. Spread the fertilizer evenly between the two circles and make sure the fertilizer does not hit the trunk. Water the fertilizer in deeply.

For tender plants, follow the label directions and apply to the soil away from the trunk or stem of the plant to prevent burning. Water deeply.

By Plant Row (Crops):

Measure the length of the plant row in your vegetable garden. Unlike lawns and ornamentals, many vegetables are heavy feeders so you don’t have to worry about overfertilization. Always follow the label instructions for amounts and frequency.

You can use 10-10-10 as a lawn starter fertilizer but a fertilizer that is higher in nitrogen is the preferred choice for a new lawn.

A good substitute would be any organic fertilizer that is somewhat balanced in its NPK ratio, such as 3-4-4. It has less nitrogen in the mix and it contains fewer nutrients overall so you would have to apply it more frequently than 10-10-10 but is safer during application for kids and pets.

It depends on whether you are using a liquid or granular fertilizer. Granular products are usually slow-release fertilizers while liquid 10-10-10 has a quicker effect.

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