With a huge choice of fertilizer products available to the domestic gardener, narrowing down your selection can seem overwhelming.
No one wants to buy or use the wrong product, especially when it comes to using high-nitrogen fertilizer as there is a lot that can go wrong if not used correctly.
For example, high levels of nitrogen can easily lead to scorching and even killing your lawn or precious plants, and if used out of season can lead to forced growth at the wrong time of year. And no self-respecting gardener wants that.
You will be pleased to know then, that our experts have been busy trialing and testing to bring to you the best nitrogen-rich fertilizers currently on the market that cover a range of different gardening needs.
Whether you’re looking for the convenience of a leading brand or in need of nitrogen-rich organic fertilizer, we’ve done the homework to turn your garden, lawn, or allotment into a green, and bountiful paradise.
- Best High Nitrogen Fertilizers
- Why Do Plants and Lawns Need Nitrogen
- When to Use a High Nitrogen Fertilizer
- Choosing A High Nitrogen Fertilizer
- Best High Nitrogen Fertilizer Reviews
- 1. Lawn Booster Nitrogen and Iron Spray 6-0-0
- 2. Scotts Turf Builder Lawn Food 32-0-10
- 3. Jobes Fertilizer Spikes For Houseplants 13-4-5
- 4. Down To Earth Blood Meal Fertilizer 12-0-0
- 5. Jobe’s Tree & Shrub Fertilizer Spikes 16-4-4
- 6. Dr. Earth Blood Meal Natural Nitrogen Fertilizer 13-0-0
- 7. Miracle-Gro Water Soluble Lawn Food 30-0-6
- 8. GreenView Fall Lawn Food Fertilizer 20-0-10
- 9. Espoma Organic Winterized Fall Lawn Fertilizer 8-0-6
- 10. Miracle-Gro All Purpose Plant Food 24-5-16
- How To Use Nitrogen-Focused Fertilizer
- When To Apply Nitrogen
- Verdict: High Nitrogen Fertilizer
Best High Nitrogen Fertilizers
If you’re short on time, then here are my best high-nitrogen fertilizers for general use, house plants, and lawns.
Best Liquid Lawn Fertilizer
Lawn Booster Nitrogen and Iron Spray 6-0-0
A high nitrogen fast-acting liquid fertilizer with iron. Perfect for applying mid-season as a booster, to achieve a greener lawn.
Best Lawn Fertilizer Granules
Scotts Turf Builder Lawn Food 32-0-10
An excellent high nitrogen granular formula with a good level of potassium to support strong roots for drought-resistant lawns.
Best Houseplant Fertilizer
Jobes Houseplant Fertilizer Spikes 13-4-5
Convenient and long-lasting fertilizer spikes from Jobe’s are by far the easiest way to maintain healthy foliage on your houseplants
Why Do Plants and Lawns Need Nitrogen
Nitrogen is an essential element that plays a vital role in the growth and development of plants. It is an important constituent of chlorophyll, the green pigment found in plants that is responsible for trapping light during photosynthesis. As such, nitrogen is critical in the process of converting sunlight into sugars, which are then used by plants as a source of energy. Without enough nitrogen, plants appear stunted, exhibit slow growth, and are generally unproductive.
Nitrogen is also a building block for proteins, which are essential for the growth and function of plants. The amino acids that makeup protein molecules all contain nitrogen, necessary to form the new plant cells required for vegetative and flower growth.
A study published by the National Library of Medicine concluded that nitrogen fertilizer significantly enlarges root biomass and individual root diameter and length, leading to increased plant size and a more robust structure.
A sufficient supply of nitrogen is crucial to ensure healthy plant growth and high fruit or flower yield. However, as nitrogen is a highly mobile element, it can be easily lost from the soil through leaching or volatilization. Or it can be used by the plants themselves leaving the soil depleted. It is in these circumstances that a high nitrogen fertilizer may need to be applied.
When to Use a High Nitrogen Fertilizer
The symptoms that indicate a need for a high-nitrogen fertilizer can vary depending on the plant species and the growing conditions. However, here are some common signs that a plant might need a high-nitrogen fertilizer:
- Stunted or slow growth: If your lawn or plants seems to be growing more slowly than expected, or not growing to their full potential, they might need a nitrogen boost.
- Yellowing leaves: Nitrogen deficiency can cause yellowing of the leaves, especially on the older leaves at the bottom of the plant. New leaves may appear pale or smaller than usual.
- Poor stem and branch development: A lack of nitrogen may cause weak, spindly stems or branches that are more prone to breakage than usual.
- Delayed flowering: Without adequate nitrogen, plants may produce fewer or weaker flowers than usual or take longer to set blooms.
- Late-season crop production: If crop yields are lower than expected or late in the growing season, a high nitrogen fertilizer could help stimulate growth and development.
If you notice any of these symptoms, it may be time to apply a high-nitrogen fertilizer to help your lawn or plants get the nutrient boost they need to grow and mature. However, it’s important to follow the instructions on the fertilizer label carefully to avoid over-fertilization, which can cause its own set of problems for your plants.
Choosing A High Nitrogen Fertilizer
There are a number of considerations when selecting a nitrogen fertilizer. The area the product needs to cover, and consequently is the product you purchase suited for distribution over the area. Do you need a slow-release product that will deliver nutrients over time in a controlled manner, or do you have an immediate problem and therefore need a fast-acting liquid formula? In this section I will explain each option and when best to use each product type.
Understanding NPK Ratio
The nitrogen, phosphorus, and potassium (NPK) ratio is a way of measuring the number of essential nutrients a fertilizer contains. The ratio is represented as three numbers separated by dashes and represents the percentage of each nutrient in the fertilizer by weight.
For example, a 10-2-4 NPK ratio means that the fertilizer contains 10% nitrogen, 2% phosphorus, and 4% potassium. These three elements are necessary for healthy plant growth and development, so it’s important to select a fertilizer based on your soil’s needs.
What Is Considered High Nitrogen
A nitrogen, phosphorus, and potassium (NPK) ratio of 10-2-4 or higher is typically considered a high nitrogen fertilizer. The nitrogen ratio should be at least double that of the phosphorus and potassium ratios combined. So a ratio of 10-2-4 means that the fertilizer contains 10 parts nitrogen for every 2 parts phosphorus and 4 parts potassium. In terms of percentages, this would mean an NPK ratio of 40% nitrogen, 8% phosphorus, and 16% potassium.
Fast Vs Slow Release
Fertilizer products are available in multiple forms, with each designed for a specific rate of nutrient release. As a general rule of thumb if you have an imminent problem with your lawn or plants or need a mid-season boost, then a fast-acting liquid formula could be a preferable option.
Whereas slow release formulas are ideal when you’re thinking ahead and putting down granules of spikes to see you through 4-8 weeks during an important growth stage.
Granules are compressed ingredients, ideal for spreading across the surface of the soil by hand or across large lawn areas by broadcasting with a fertilizer spreader. They dissolve slowly when in contact with moisture providing a slow release of nutrients over time.
Spikes are similar to granules, in that they are compressed ingredients, but this time in the shape of a spike or stick. They are pushed into the soil and dissolve over an 8-week period making them ideal for trees, shrubs, and large individual plants.
Liquid Concentrate is a fast-acting fertilizer. The nutrient is suspended in a water solution and penetrates the soil quickly, with the whole nutrient content available to the plant immediately. This is ideal where a fast response is required to lush up a lawn or fix an ailing plant.
Organic Vs Synthetic
Whether you choose an organic product or synthetic is a matter of personal choice. The trade-off is often the environmental impact of chemical fertilizer versus a lower performance, and more often than not, a more expensive organic fertilizer.
Synthetic fertilizers, are processed and typically contain chemical formulations. This provides the advantage of designing a very specific fertilizer product that can be far more effective than an organic natural product. The downside is the environmental impact of chemicals leaching into the water table.
Organic fertilizers are derived from natural sources such as animal by-products or plant material. They are available in single ingredients (e.g. bloodmeal), or blended forms as a general fertilizer. The main benefit is that they are 100% organic and present little risk.
Organic Sources Of Nitrogen
- Blood Meal 12-0-0
- Feather Meal 12-0-0
- Worm Castings 1-0-0
- Rabbit Manure 7-2-0
- Tea Leaves 4-1-1
- Silkworm Cocoons 9-1-0
- Bat Guano 7-3-1
If you have an abundant supply of one or more of these materials at home and can process it for use, it could be a great organic option. But in practice, it isn’t really convenient given the quantity required and the processing required to allow you to distribute it evenly across your lawn.
As an example, for use on lawns, you will need to powder it or produce a liquid ‘tea’ form of fertilizer for each application. So understandably, most people will prefer to buy a bag of synthetic granular fertilizer, suited for broadcasting, and giving a slow release of nutrients.
Lawn fertilizer needs to be easy to apply, given the area that typically needs feeding. Slow-release granules are often the best option for broadcasting early in the growing season. Then follow that up in summer with a hose-end spray liquid lawn fertilizer to deliver an immediate boost to achieve a greener lawn.
Fertilizing Trees and Plants
For trees, plants including houseplants, a granular top dressing, or perhaps a fertilizer spike of larger specimens will be a very convenient way of delivering a controlled release of nitrogen over a 6-8 week period. Switching to a liquid concentrate later in the season, that can be watered in using a watering can.
Best High Nitrogen Fertilizer Reviews
Our team has searched far and wide to find the best high-nitrogen fertilizers available for general consumers’ use. Our priority was the quality of the nitrogen fertilizer nutrient balance, overall performance, and ease of application.
As well as my own testing and that of colleagues’ previous experience of using these products, we also take into account customer reviews across the major online retailers and growing forums showing the level of customer satisfaction these specific products have delivered.
- Commercial Grade Lawn Energizer with nitrogen and iron
- Exceptionally easy to use, screw on to hose and spray
- I have had years of outstanding results with this company’s products. They are excellent.
This ready-to-spray lawn fertilizer from Simple Lawn Solutions is my favored lawn booster. It has a high nitrogen content with iron, which means it provides a nice green lush lawn. This is a commercial-grade product developed for professional use. But, it is just about as simple to use as you could imagine. Just screw the hose attachment to your garden hose and spray.
This lawn fertilizer is good for all grass types including Bermuda, Zoysia, St. Augustine, Buffalo, Centipede, Florida Palmetto, Bahia, Fescue, Ryegrass & Kentucky Bluegrass. This single hose connector bottle will treat around 3,000 square feet.
This is an excellent product from a fantastic range developed by Simple Lawn Solutions. I am a huge fan and cannot recommend it highly enough.
How To Use: Connect the hose attachment to the end of any standard garden hose pipe. Turn the thumbscrew to release the flow and work the spray back and forth across your lawn.
- NPK ratio of 32-4-7 provides high nitrogen as well as potassium for strong root growth
- Includes organic ingredients such as kelp and feather meal
- Easy to apply in granular form, every few months during the growing season
- Can be expensive compared to some other brands
- May cause an imbalance in the soil if too much is used
Scotts Turf Builder Lawn Food 32-0-10 is a great choice for anyone looking to give their lawn the nutrition it needs to stay green and healthy throughout the growing season. The NPK ratio of 32-0-10 is ideal for strong foliage growth, but also provides a good level of potassium for strong root development, improving the lawn’s resilience to dry weather and drought. This product is available for grasses in southern regions as a 32-0-10 where drought tolerance is a higher priority and a formula for northern regions 32-0-4.
This formulation is designed to be used from spring through to late summer, with multiple uses over the year to keep the grass lush and green.
What’s interesting about this fertilizer is that it includes high-nitrogen synthetic ingredients, but also organic ingredients such as kelp meal and feather meal avoiding being a 100% chemical-based formulation. These organic ingredients will also sit within the soil and moderately improve its texture over time.
How To Use It:
Water your lawn prior to application. Check the packaging to find the correct setting for your fertilizer spreader. Work around the outside perimeter of your lawn, and then back and forth across the interior section. Water your lawn again 24hrs after application.
- High nitrogen fertilizer spikes perfect for a ‘feed-and-forget’ approach to houseplant care
- Almost impossible to get the fertilizer dose wrong
If I only had one choice for my houseplant fertilizer, then it would be Jobe’s Fertilizer Spikes for Houseplant. They are by far the easiest approach to maintaining beautiful, healthy houseplants. If you have as many houseplants as we do in our home, then refilling the watering can and reapplying liquid fertilizer is just a bit too much of a chore. That’s where spikes come into their own.
How To Use: Simply push between 1-3 spikes into the planter soil and that’s it. Spikes will last most of the growing season, in some cases, you may repeat the application one more time. But it is a super-efficient approach to houseplant care.
Miracle-Gro also has a houseplant fertilizer spike but it has a nutrient ratio of 6-12-6, so if you’re after green foliage then Jobe’s is the best high-nitrogen fertilizer spike on the market in my experience.
- 100% organic single-ingredient fertilizer
- Easy to apply, just sprinkle or broadcast
- Presents no risk to animals or waterways
- May attract the interest of wildlife
- Relatively expensive to use over large areas
Bloodmeal is a traditional, organic, high-nitrogen fertilizer. It provides a readily available source of nitrogen in powder form, for use as a top dressing or base dressing. This is the perfect nitrogen fertilizer for vegetable beds. Great for heavy feeders such as corn, broccoli, and leafy greens with an NPK 12-0-0.
If organic, traditional gardening is your priority then there’s no need to look any further than blood meal. The one downside of using animal-based products is that they ironically attract interest…from animals. But this is true of blood meal, bone meal, and fish meal. It’s advisable to take extra precautions to protect your crop if you have a risk of deer or other large animals in the surrounding area.
How To Use: For vegetable gardens, prepare 3lbs per 100 square feet and apply as a top dressing to be worked into the soil and water for best results. For container plants use 1-2 tables spoons per gallon of soil.
Easy to insert into the ground around each tree or shrub
Provide essential minerals that help promote healthy plant growth
Last up to 8 weeks, making them very convenient to use
May not be suitable for very stony, or very dry soil.
Jobe’s Tree and Shrub Fertilizer Spikes are excellent for providing your trees and shrubs with a high nitrogen formula over an extended period of time. I have been using these spikes for a few years now, and really appreciate how simple and convenient they are to use.
Each spike provides a high nitrogen boost, along with other essential minerals that help your plants grow including, iron, phosphorus, magnesium, and other trace elements. These spikes are designed to feed your trees with a gradual release of nutrients lasting up to 8 weeks. I found the more rain we get the quicker they tend to dissolve, but 6-8 weeks is normal.
How to Use: The dose depends on the tree trunk diameter, with smaller trees (1-2-inch diameter) requiring a single spike placed 30 inches out from the trunk. Then as the tree size gets larger you can add more spikes following the instruction on the packet.
It’s a good idea to soak the soil prior to application as the spikes are made from compressed minerals. So in some cases, you may need to hammer them into the ground, so pre-soaking the soil helps them go in without crumbling.
- An excellent 100% organic high-nitrogen fertilizer
- Perfect for use on plants and vegetable beds
- Dr. Earth TruBiotic assists microorganism development within your soil
- Your dog will love this stuff, so be sure to consider how and where you use it
Dr. Earth Natural Blood Meal is a premium quality, organic fertilizer for use with plants and vegetables. The nutrient ratio of 13-0-0 is one of the highest you will find in a 100% natural product. The name of this product gives a clue as to where the nitrogen comes from, but Dr. Earth supplements this with plenty of really useful ingredients. Their TruBiotic formula is a biological soil inoculant. Now, what that really means is it contains beneficial microbes and fungi to bring life to the soil by supporting microorganism development.
How To Use: For new plantings use blood meal as a part of your soil amendment and mix to a depth of 4-8 inches within the planting hole. Use 3 tablespoons per shrub. For established plants in borders apply at a rate of 12 cups per 10 sq ft and mix into the soil well.
- Stripe-free, deep green grass with visible results in one week
- Water-soluble for use with a spray kit or watering can
- Suitable for all grass types
- Premium price for a premium brand
Yes, it’s Miracle-Gro again! When compared to the many other products I have tried over many years of treating lawns, Miracle-Gro just delivers predictable and reliable results. I guess that’s why it’s the biggest brand on the market.
This purpose-made lawn feed is formulated for turfgrass with high nitrogen and chelated iron; it feeds through both the roots and grass blades.
This general-purpose, high-nitrogen fertilizer is specifically designed for use on your lawn. 1.25lb covers up to 7,00 sq feet of lawn. NPK 30-0-6. Recommended use every 2-3 weeks throughout the growing season for the best results. Go to Miracle-Gro Lawn Food on Amazon
How To Use: Apply using Miracle-Gro Garden Feeder Spray and cover 1000 sq ft in 12 minutes. Or simply use 1 tablespoon for every gallon of water and mix and apply with a watering can.
- Great for strong spring growth
- Slow release, feeds for 8 weeks
- Low cost for large coverage
- Can use in a broadcaster or drop spreader
- Needs to be applied in fall/autumn
- May still need a liquid feed throughout the growing season
If your looking for a slow-release, granular feed then GreenView Fall Lawn Food may be right for you.
A granular feed has different qualities than a liquid spray feed. You will need to apply the granules in the fall and leave it sitting over winter. This will give your lawn a head start in spring by up to 2 weeks and offer 8 week feeding period to allow the grass to really establish a strong root system. Being granular, it can be broadcast with a spreader for quick application.
We recommend applying a fall feed and following it up through the growing season with a liquid fertilizer spray every 2-4 weeks for the best results.
16lb of the product will cover 5,000 square feet of lawn. NPK 20-0-10. Check the latest Greenview price on Amazon.com
How To Use: Apply at a rate of 3.2lb per 1,000 sq ft. using a drop spreader or broadcaster. For cooler climates, apply 2 treatments per year, for warmer climates apply 4 applications per year.
9. Espoma Organic Winterized Fall Lawn Fertilizer 8-0-6
Best Organic High Nitrogen Fertilizer For Lawns
- 100% Organic
- Can be used in a broadcast spreader
- Added potash to support healthy root development
- Organic nature makes it more expensive than other product
Espoma Organic Fall Fertilizer works in much the same as GreenView Lawn Fall Food. Apply in the fall and you will get an early boost on your lawn, with an extended feeding period from the slow-release formula resting in the soil. The only real difference is Espoma’s Organic ingredients, making it pet and child safe.
Made with feather meal, poultry manure, and potash, it’s an easy product to apply as a top dressing, without the risk of scorching or burning your lawn. 30lb covers 5,000 square feet. NPK 8-0-6. Find Espoma Lawn Food here
How To Use: Apply between late summer to November. Apply to a dry lawn that has recently been mowed, and fill your drop spreader or broadcaster with 6lb of fertilizer per 1,000 sq ft. If no rain is forecast, it is best to water the fertilizer to activate it.
- Proven track record of delivering results
- Easy to use and fast-acting
- No scorch guarantee
- Premium price for a premium brand
When it comes to commercially manufactured, high-nitrogen fertilizers, there are not many products that can match Miracle-Gro’s product range and proven track record. Based on performance alone, many people will argue it’s the best nitrogen fertilizer on the market.
Of course, the beauty of this product is the convenience factor. Use this with Miracle Gro’s Watering Hose Garden Feeder Kit, allowing you to water it into very large areas in no time at all. Or just pour the stated amount of product into your watering can or sprayer and apply it to your lawn, plants, or vegetables. Check Miracle-Gro prices on Amazon.com
This general-purpose, high-nitrogen fertilizer is suitable for indoor and outdoor use. 1.5lb covers 600 sq feet of garden. NPK 24-8-16. Recommended use every 1-2 weeks.
How To Use: this 8oz packet of Miracle-Gro is a water-soluble granular feed. There are no hard and fast rules, the manufacturer recommends using it every 7-14 days. However, I would suggest you use it once a month through the growing season, then less throughout the plant’s dormant period.
Simply mix one spoon of fertilizer in your watering can for every gallon of water.
How To Use Nitrogen-Focused Fertilizer
There are different ways to apply high-nitrogen fertilizer but according to the University of Nebraska, it is vitally important to consider the 4 Rs when it comes to its use. The 4Rs cover the right amount, right source, right time, and right placement so it is worth checking the manufacturer’s labels for specific instructions when using commercially purchased products.
Here below, are the various ways this fertilizer can be used to best affect.
Topdressing is a method used for powders and granules. It is best to apply top dressing in spring, according to The Gardening Fix the vegetative growth stages of plants and vegetables, benefit significantly from regular low doses of nitrogen top dressing. Right up until the formation of flower buds, when it is recommended to switch to a more balanced fertilizer or a product with higher phosphorus and potassium, to support flower or fruit production.
Broadcast the material across grass using a drop spreader or place it around the base of plants, avoiding direct contact with leaves or flowers, to avoid scorching. Topdressing will provide a slow release of the fertilizer as it dissolves and seeps into the soil.
A base dressing is where you incorporate the fertilizer into the soil or growing medium. Basically, apply a top dressing and dig in, or mix directly with potting composts or soil during the planting or re-potting process.
Watering in fertilizer is applicable to liquid feeds. Generally, you will be required to mix the concentrate with water (ideally rainwater) and spray or pour it into the soil around the plants. This will provide faster absorption and can be a great way of providing a ‘recovery’ shot of macro-nutrients to plants showing signs of slow growth or boosting root development.
A foliar spray is simply a diluted concentrate sprayed directly on the vegetative growth to correct nitrogen deficiencies. The most tender parts of the plant will provide better absorption of nutrients. Take care to avoid foliage spray in bright, strong sunlight (which can cause scorching) or just before the rain (to avoid washing off). Foliage spray tends to be reserved for highly diluted natural products, as chemical fertilizers can burn leaves and young plants.
When To Apply Nitrogen
There are two main uses for nitrogen fertilizer, for use on your grass to create a healthy, lush green lawn, or for use on plants and vegetables to help develop strong, healthy foliage and structure.
Let’s look at the various uses of fertilizers that contain high amounts of nitrogen to clarify when you should consider using them. But the same principle applies that nitrogen uptake is at its highest level through the growth stage of vegetation, so it’s important not to lose sight of that basic principle.
Nitrogen For Grass
The application of nitrogen fertilizer on grass is intended to provide a healthy-looking lawn throughout the growing season, so typically from March through to November. The time to apply it will depend on what the product you are using is designed for. For example, Espoma Organic Fall Fertilizer was developed for application in fall and sits over winter to provide an early boost of nutrients right from the get-go in spring.
Nitrogen For Plants
With the majority of plants growing throughout the summer season, spring tends to be the preferred time for nitrogen fertilizer use. It is important to restrict high nitrogen use leading up to and during the flowing season, so as not to force too much foliage growth at the expense of blooming flowers or fruit.
Houseplants are no different from plants that grow in your backyards or garden, they need a boost during the most active growth stage. So, use it sparingly, once or maybe twice, early to mid-season on mature houseplants. For tender young plants, just rely on good quality compost to do the job for you.
How Often To Use Nitrogen
Slow-release fertilizers will last for months, sometimes all growing season. So, check the manufacturer’s instructions. Never over-fertilize with a high-nitrogen product, they are potent and can cause plant or lawn damage. When in doubt, less is better than more.
Verdict: High Nitrogen Fertilizer
That concludes my review of the best nitrogen fertilizers for general use and for lawns and plants. In summary:
If you intend of delivering a fertilizer schedule onto your lawn in spring, and again during summer, then opt for a slow-release granular product. The best option has to be Scotts Turf Builder Lawn Food 32-0-10. Its slow-release formula will last for up to 3 months in my experience, so apply it in spring and mid-summer.
For lawns that need a boost throughout the season, I would recommend Lawn Booster Nitrogen and Iron Spray 6-0-0 which I have had a fantastic track record with year after year. It’s very simple to use and works within 7 days, showing notable improvements.
For houseplants, I like to use Jobes Houseplant Fertilizer Spikes 13-4-5, which I push into the soil and forget…which is perfect for me and my lifestyle.
Consider what you intend to use your nitrogen fertilizer for and whether you need a powder, granule, or spray. Then, your own priorities will decide the rest; organic, low-cost, or a brand with a proven track record of delivering time and time again.
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