When to Use 10-10-10 Fertilizer? | How to Use Triple 10

Out of all the different NPK ratio options available for your plants today, there is one that offers balanced nutrition with far less risk of root burn and overfeeding. This is the ever-popular 10-10-10 fertilizer. 

With just 10% each of nitrogen, phosphorus, and potassium, this NPK can be used for a wide variety of applications. Lawns, vegetables, evergreens, and ornamentals can all benefit from it, depending on soil conditions, plant variety, and growing stage. 

When to apply a 10-10-10 NPK, and how much, will be relative to each plant type. Which we’ll discuss more in detail, further on.

Understanding 10-10-10 Fertilizer Labels?

Trying to figure out if a 10-10-10 fertilizer is the best one for you, may seem daunting. When all you want to do is to grow healthy plants without breaking the bank. Well, there is hope on the horizon! You can easily match an effective fertilizer to your specific plant goals by understanding the fertilizer labels. 

Most manufacturers will state the NPK ratio of their product on the label. Which will reflect how much nitrogen, phosphorus, and potassium the product contains. On the back of the container should be an ingredients list, just like you’ll find on grocery store items.

This list reveals all the ingredients that make up that product. First, the NPK content (macronutrients), then all secondary micronutrients like calcium and magnesium. Followed by trace elements such as copper and manganese. Lastly, will be any fillers the manufacturer may include, for an easy-to-use product.

N-P-K Ratio

So, how exactly do you decipher an NPK ratio? If you’re not familiar, an NPK ratio is three numbers, separated by dashes. This indicates the fertilizer’s proportions of nitrogen, phosphorus, and potassium.

As mentioned, a 10-10-10 NPK has 10% nitrogen, 10% phosphorus and 10% potassium. Every plant requires these three elements in order to thrive. Just in different proportions or NPK ratios.

Each of these macronutrients plays a vital role in cell formation, photosynthesis, and flower production. All working in tandem to create a healthy, bountiful plant. And when applied properly, they can increase soil fertility and beneficial bacteria activity, too. Read Plant Food Vs Fertilizer to understand the differences between the roles of plant nutrients and photsynthesis in plant growth.


Nitrogen plays a key role in encouraging the growth of healthy, green foliage, by fueling the production of chlorophyll. This gives foliage its green color and ensures that photosynthesized energy is available to convert starches and carbohydrates into food. 

This multi-tasking macronutrient also fuels the proteins and enzymes that regulate water and nutrient uptake and disbursement. High nitrogen fertilizer is typically formulated for lawns and other plants where foliage is the primary focus.


Phosphorus is a major contributor to the process of photosynthesis. Once the chlorophyll is produced, this macronutrient triggers the energy captured by the chlorophyll to convert starches and carbohydrates into food. High phosphorus fertilizers assist with the creation of abundant flowers and fruit, rather than foliage. 

Phosphorus begins its work at the cellular level. It contributes to the construction of those same proteins and enzymes that nitrogen uses to regulate water and nutrients.


This final macronutrient is primarily responsible for the circulation of water, nutrients, and photosynthesized food throughout your plants. Yet, it also activates those proteins and enzymes that were formed using phosphorus and nitrogen to build healthy plant structures. 

Proper amounts of potassium contribute to a plant’s resistance against disease extreme heat and drought by helping them to conserve moisture. High potassium feeds are the perfect fertilizers for tomatoes or other vining crops such as squash and melons as they help to encourage large, well-formed fruit. 

What is Triple 10 Fertilizer Used For?

The intended use of a triple 10 fertilizer is to increase plant success and soil fertility, while not overwhelming your plants. This would also apply to houseplants, given the low percentage of each macronutrient. 

For plants grown in hanging baskets, a triple 10 fertilizer can give you an advantage against the heavy water and nutrient leaching that occurs. Allowing your plant’s consistent access to nutrients, as they grow.  

When applied to ornamentals and vegetables grown in fertile soil, a 10-10-10 NPK will encourage vibrant foliage for optimum photosynthesis. While providing maximum support for flower and fruit formation. Although, many fruiting plants may need more phosphorus and potassium, once buds are set.

For in-ground annuals and perennials, a 10-10-10 NPK will provide consistent nutrients, just as in hanging baskets and pots. Fewer applications will be needed here though, due to increased moisture and nutrient retention.

Why Use a Balanced Fertilizer?

Some outdoor plants require more of one macronutrient than another. But, when planted in poor soil, a balanced fertilizer can provide a nutrient-rich environment that promotes healthy growth. 

It is also possible to add certain organic elements to increase the benefits of macronutrients when needed for flowering and robust fruit formation. This includes chopped banana peels for potassium and bone meal for phosphorus. 

Indoor plants benefit from a balanced fertilizer due to more frequent watering and the leaching of vital nutrients from the soil. An equal NPK will keep the growing medium fertile enough to keep them happy.

How Often to Use 10-10-10 Fertilizer

Liquid options can be applied to vegetables and ornamentals once a month to maintain a steady stream of nutrients. In well-composted soil, every other month is sufficient. 

Turfgrasses can use a triple 10 fertilizer 3 times per year, beginning in the spring. You can expect to see results from just one application within a week.

With slow-release options, like granules or spikes, even fewer applications are necessary. With beneficial soil microbes and periods of rainfall doing the work for you, while also enriching your soil. 

Results with these take a bit longer to see but the increased benefits are well-worth the wait.

10-10-10 vs 8-8-8 Fertilizer

In terms of fertilizing, plants are typically categorized as heavy, medium, or light feeders. From this perspective, there isn’t much difference between a triple 10 and a triple 8 fertilizer (10% of each macronutrient vs 8%).

But, when using it to cover large plots, it’s important to note how much more of an 8-8-8 NPK is needed to reach optimum nutrient availability, than a 10-10-10. 

For example, 12.5 lbs of a triple 8 fertilizer would be needed (per 1000 sq ft) in order for the full NPK to be available to every plant. Only 10 lbs are needed with a triple 10. When cost is a factor, a triple 10 is often more economical.

Fertilizer Type

There are several application types available that make the process of nourishing your plants and soil less strenuous and more enjoyable. These fall into four different categories: 

  • Quick Release – these liquid or water-soluble options offer an immediate uptake of nutrients. Resulting in accelerated, visible improvement for plants growing in poor soil.
  • Slow-Release – Heavily concentrated, granules and spikes offer a steady stream of nutrients over an extended period of time. Rather than inundating plants with high doses all at once. 
  • Organic – made from strictly natural materials like well-rotted plant material and animal bi-products that, when combined, meet the required NPK levels of most plants. 
  • Inorganic – manufactured with minerals and synthetic chemicals. These can result in a higher yield. But, they can also potentially contaminate soil and nearby water sources.

Liquid Concentrate

Liquid concentrates are used by mixing in a recommended amount of water and applying it around the base of plants. Some are also formulated to be used as foliar sprays and are quite effective when leaves show signs of nutrient deficiency. 

Premixed options are available as well, but maybe a bit higher in price. Once applied, nutrients are immediately carried to the root system through the soil or leaves.

Liquid feeds tend to keep the pH levels in your soil balanced, as well. However, caution is recommended, as over-feeding is common and could lead to root burn.

Water Soluble Powder

Water-soluble, powder fertilizers can be applied either directly into the soil around the base of trees, shrubs, and plants or diluted in water as a “tea”. This type is perfect for larger applications such as expansive allotments or home vegetable gardens.

As a dissolvable, the effectiveness per application is fairly consistent. As nutrients are equally dispersed throughout the solution when mixed with water. 

Powders are some of the most economical and carry the benefit of virtually indefinite shelf life. But, they do carry a risk of root burn, if exact measurements are not followed.

Slow-Release Granules

Granules are a slow-release choice. Heavily concentrated, these can provide consistent nourishment for up to nine months, with the first results showing in just a couple of weeks.

They’re also less likely to cause root burn and are considered more eco-friendly. This is because no watering is needed to activate, and the product is less likely to leach into nearby surfaces or groundwater. 

Granular fertilizers are applied by casting them evenly around the base trees, shrubs, and plants. They can safely feed crops longer into the growing season and support even growth on lawns, while reducing the amount of fertilizer required, per season.

Fertilizer Spikes

Spikes are one of the most convenient to use, especially if you have a substantial container garden. Pre-measured in various sizes, they’re easy to push into loamy soil.

In compacted soil under large trees, simply water the area to be fertilized first. Then, gently tap spikes into softened soil with a rubber mallet.

This form of nutrient released by micro-organisms that naturally live in the soil carries the added benefit of stimulating an increased resistance to disease and pests.

And being slow-releasing, they run little risk of root burn. Unused portions can then be stored mess-free until needed.

How and When to Use Triple 10 Fertilizer

A triple 10 fertilizer can be applied as a liquid or by working slow-release granules or spikes into the soil. 

When planting saplings in nutrient-weak soil, a handful of 10-10-10 granules can be added to the hole prior to planting. Roots establish more quickly and encourage new growth. 

In new garden beds, working granules into the top few inches of soil or applying a water-soluble option, just after planting, will provide plants with a great start. 

When used as a vegetable fertilizer, applying a triple 10 NPK just after transplanting will contribute to an abundant harvest. 

For flowering and fruiting veggies, follow this up with an NPK higher in phosphorus and potassium, once buds set. 

When used as directed, a 10-10-10 NPK is far less likely to cause the kind of burning that can result from high doses of nitrogen. But, despite the low ratio, care must still be taken not to over-apply it.

Trees and Shrubs

When used as a fertilizer for evergreen trees and shrubs, a triple 10 fertilizer can help to establish strong root systems and produce healthy color and size faster when for a month or two after planting. 

Increased soil fertility will also help these large plants develop an effective resistance against extreme temperatures. And to conserve moisture in times of drought.

Once established, perennial evergreens typically don’t require any further fertilizing. But, if browning or loss of foliage occurs out of season, a good soil test should be conducted to reveal what nutrient is lacking and needs to be added to the soil.

Citrus and Fruit Trees

Fruiting trees typically need more of one macronutrient than another at different times. So a triple 10 may not be suitable for them, in the long term. This includes berries, stone fruits, and citrus.

But, if you’re planting these in poor soil, adding a few handfuls of dry 10-10-10 granules into the planting hole in spring will help them get established quickly. And contribute to a bountiful harvest, come summer and fall.


Ornamentals, in beds, pots, and hanging baskets, need consistent access to nutrients in order to produce lots of vivid, summer color. A triple 10 NPK can ensure this and help accelerate plant maturity in annuals. Resulting in buds and flowers appearing sooner.

Unless, they’re already growing in rich, fertile soil. In this case, a watered-down dose of 10-10-10 will better support a nice show of healthy stems, leaves, and blooms, without running the risk of overfeeding.  A full 10-10-10 NPK in rich soil may force extra growth and blooms but at the expense of the overall health of the plant.

Vegetable Gardens

Green, leafy crops like broccoli, cabbage, and lettuces grow best when side-dressed with a triple 10 NPK, roughly a month after planting. As do kale, celery, and asparagus. Showing strong root development and vigorous growth.

Tomatoes, squash, and melons require more phosphorus and potassium once buds are set. Even those grown in pots will need more to produce large and well-formed fruit. 

If you’re starting with poor soil, it’s better to start out with a 20-20-20 NPK after transplanting. But, once buds are set, less nitrogen is needed. Otherwise, you’ll have a lot of foliage and few flowers and fruit.

Is 10-10-10 Good for Tomatoes

When first planted in nitrogen-poor soil, a 10-10-10 NPK will provide new seedlings with a healthier growing environment that will encourage a robust root system and vibrant foliage. But, beyond the first month of growth, a 5-10-10 fertilizer would be more appropriate.

Continuing with a triple 10 will produce lots of pretty green leaves, but with few flowers or fruit. The same applies to all varieties of squash and melons. 


Houseplants also need the right ratio of nutrients to form strong roots and healthy foliage. But, due to the frequent leaching of water and nutrients, they’ll need a consistent stream of it. 

A 10-10-10 NPK will do just that without risking damage to roots and foliage. 

An exception would be when using fertilizer for African violets, bromeliads, and other flowering houseplants. These need more phosphorus to form flowers and nitrogen for vibrant foliage. These do well with a 7-9-5 NPK.

When adding extra nutrients to houseplants, please do so with caution. Just as with outdoor plants, too much can overwhelm and kill your plant.

Lawn and Grass

Most liquid fertilizers for lawns and grasses include higher doses of phosphorus to produce a thick, lush blanket of color and form with robust root systems. They also rely on higher levels of nitrogen to maintain a vibrant structure that’s also resistant to wear-and-tear, excessive heat, and drought.

When starting a new lawn fertilizing regimen, using a 10-10-10 NPK is a great place to start. If you haven’t tested the soil beneath, this will provide adequate nourishment without risking root and blade burn. 

Excessive amounts of any macronutrient on lawns and different grass types may end up causing root damage ultimately killing them.

10-10-10 Fertilizer FAQ’s