best fertilizer for knockout roses

Best Fertilizer for Knockout Roses | Reviews in 2022

Knockout roses are quite famous for landscapers and gardeners. They grow in rows or groups and can adapt to various environments. These flowers are easy to take care of and known for their extended blooming season. 

This family of roses is not hungry feeders, but fertilizer will help them thrive and make a beautiful and long-lasting bloom. 

In this article, we will introduce you to fertilizer for knockout roses. These fertilizers are the top selections available in the market. We will tackle each of them so that you can decide the perfect one for your flowers. 

So without further delays, let’s get right into it!

Best 7 Fertilizers for Knockout Roses in 2022:

In this review, we will tackle some of the best products out there. Each of which is sure to provide you with top-notch features. Let’s delve on these fertilizers further.

1. Jobe’s Organics Knockout Rose Granular Fertilizer

If you want an excellent fertilizer, Jobe’s Organics is here to offer you guaranteed results. This pack comes in a convenient 16-pound size and is excellent with a knockout, tea, hybrid, and heirloom roses. More so, it is a fertilizer that is specifically designed for organic gardening. 

This formula is fast-acting granular fertilizer that has a 3-4-3 NPK ratio. Even if you directly apply it to your flowers, there is no possibility of plant burn. For great results, the correct application is every 4 to 6 weeks. But if you think you have to put more, do not hesitate and apply it as needed. 

As a plus, it also contains Jobe’s exclusive biozone microbe formulation that comes with archaea. By this, you will notice that the soil condition you are working on is improving. It also helps your plants resist the risks of drought, diseases, and insects.

Finally, this fertilizer is the number one organic and natural plant food brand that is very much trusted in doing home gardening. Furthermore, it is OMRI registered and ideal for soil preparation and established plants. Surely, Jobe’s Organics is an excellent pick for your knockout roses.

Special Features
  • Has Jobe’s exclusive biozone microbe formula
  • Designed for organic gardening
  • Even if directly applied, it won’t burn plants
  • Number one organic and natural plant food

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2. Urban Farm Fertilizers Professional Rose Fertilizer

If you are in the mood for a custom-blended fertilizer, Urban Farm Fertilizers is here to offer you an excellent fertilizer for roses. It is super concentrated with a ratio of 256:1. This statement means that with only one gallon, this rose fertilizer can accommodate 256 gallons of high strength formula. 

Additionally, it is straightforward to prepare with just a shake and mix motion. More so, it is 100% complete in nutrition, including calcium for fast and explosive growth. This one is incredible for it is made from organic components, humic acid, mycorrhizae, enzymes, kelp, and minerals. 

Urban Farm Fertilizers are hand-crafted and micro-brewed with an NPK ratio of 4-4-3. It is perfect for hose-end sprayers, drip systems, foliar feed, hydroponics, and even hand watering. 

Therefore, if you want to have a high-performance fertilizer with visible effectiveness, turn to Urban Farm. Your plants will undoubtedly grow to their fullest bloom, which will make your garden an attractive one.

Special Features
  • The super-concentrated formula of 256:1
  • Fertilizer is hand-crafted and micro-brewed
  • It has a 4% Calcium for explosive growth
  • Full of nutrients and 100% water soluble
  • Contains organic components, humic acid, mycorrhizae, enzymes, kelp, and minerals

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3. Miracle-Gro Water Soluble Rose Plant Food

Adding to this list is a fertilizer that will instantly make your roses bigger and more beautiful. Miracle-Gro is the best rose food for knockout roses, which is soluble with water. This container can hold up one and ½ pound of fertilizer.

Well, it contains nitrogen, phosphorus, and potassium for better growth of your flowers. Unlike its other competitors, it is designed explicitly for roses and is endorsed by the American Rose Society.

You can simply apply this fertilizer using any watering can, and you are recommended to feed your plants every 1 to 2 weeks. Even you directly apply this one; you will be sure that it won’t burn your plants.

Finally, when you use this product, you can be sure that your flowers can receive appropriate nutrients. And due to its liquid form, it is very much suited for newly planted plants. Therefore, it is unquestionably beneficial for young gardens.

Special Features
  • Endorsed by American Rose Society
  • Will not burn your plants even if directly applied
  • Makes your plants grow more prominent and more beautiful
  • Recommended to feed roses every 1 to 2 weeks

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4. Plants for Pets Gardenia Fertilizer Shrub or Flowering Plant Food for Pot and Shrubs

Next up is a fertilizer and plant food that is offered to us by Plants for Pets. It is an accurate gardenia plant fertilizer that, when applied to plant soil, you would have the experience of fantastic flower growth.

You can grow your plants thoroughly with the fertilizer’s miracle ratio of 3-1-2. This liquid fertilizer ratio of nitrogen, phosphorus, and potassium are developed by the manufacturer to promote a beautiful growth of gardenias.

And because this formula is specialized for gardenia flower species, you can surely yield a healthy flowering plant. Furthermore, one teaspoon of this plant food can make the right solution of two cups of water. The mixture is advisable to apply to your gardenia twice a month in days in which the sun is very bright.

Therefore, this fantastic fertilizer promotes health optimization and will bring out the best of your cheerful flowers. You should include this fertilizer on your potted flowers and display a beautiful specimen in the terraces to offer you better attraction.

Special Features
  • A gardenia plant flood
  • Has NPK ratio of 3-1-2
  • This product is water-soluble
  • Due to this fertilizer, you can yield delightful flowers
  • Gives you the capability to nurture indoor plants

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5. Miracle-Gro Shake ‘N Feed Rose and Bloom Plant Food

Another addition to this list is a plant food that promotes spectacular colors and delicate blooms in your flowers. This one the Shake ‘N Feed fertilizer form Miracle-Gro that helps you have healthy and vibrant plants. 

Like the other options, this one also provides many micronutrients and natural ingredients to nourish above and below the soil. Moreover, this product is formulated with kelp, feather meal, earthworm castings, and bone meal for an all in one detail. 

Miracle-Gro’s plant food can be used anywhere, namely in-ground or in containers. You can feed your flowers for up to three months when using this product. As a plus, it is very beneficial because it can be used on new plants and existing roses and flowering plants.

Special Features
  • Contains natural ingredients to feed microbes on soil
  • Great for new plants and existing roses
  • Able to be used for grazing for up to three months
  • Can be conveniently applied on all flowering plants
  • Fertilizer can yield you spectacular colors and more blooms

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6. Bayer Advanced All-In-One Rose and Flower Care Concentrate

In case you do not want to do some spraying methods, this product from BioAdvanced is the one you need. All you have to do is to measure, mix, pour it around the plant base, and provide complete care for your rose and flowers.

For a fantastic feature, this fertilizer is a three systemic product incorporated into one bottle. It can control pests, kills, and prevents fungal diseases and has an NPK ratio of 9-14-9. This blended fertilizer also has rainproof protection that lasts for up to six weeks. 

Furthermore, this fantastic fertilizer promotes strong roots and adorable blooms for a great appearance. Its insect control is superb and will take away adult Japanese beetles, aphids, and other pests around your flowers. For disease control, it can fight black spots, rust, powdery mildew, and southern blight. 

This product is undoubtedly very beneficial and will give you a high percentage of satisfaction. Use this plant food and see how healthy your flowers can be.

Special Features
  • No need for spraying
  • With systemic rainproof protection of up to 6 weeks
  • Has insect control and disease control
  • Promotes strong roots
  • 9-14-9 blended fertilizer

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7. Dr. Earth Rose and Flower Fertilizer

For the last product, Dr. Earth fertilizer is a 24-ounce formula that will make superior flowers and larger roses. This last option is infused with beneficial microbes that will enhance your plants’ growth in no time.

There are organic nutrients that must break down thoroughly and be released on the soil. By that manner, the roots of the plants can absorb them easily and as they are needed. More so, it is rich in prebiotic, which maintains healthy soil.

Most importantly, this plant fertilizer is safe for people and pets. It ensures you a high safety against the harmful effects of toxic chemicals. Given that it is natural and organic, it is best in quality. 

Therefore, if you want a healthy and abundant bloom for your roses and other flower species, use this Dr. Earth fertilizer. It is a money-wise decision, and also, your safety is its top priority.

Special Features
  • Product is infused with beneficial microbes for enhanced growth
  • Fertilizer is natural and organic
  • It will give you more massive and abundant bloom
  • Product is safe to people and pets
  • Can yield you superior flowers

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When to Fertilize Knockout Roses?

Experts say that you have to let knockout roses grow on their own accord before you can fertilize them. However, once the roses have gone through one complete bloom cycle, they are ready to be fed.

For a fact, these flowers bloom every four to six weeks starting from spring and up to the first frosty season. Specifically, eight weeks before the frost is not a good time if you live in areas with colder climates. If you follow this consideration, you will allow buds to acquire less frost damage.

You should not put fertilizer on knockout roses in the late summer. That season is where the roses are not actively growing but are already in full bloom. 

Besides, this family of roses can grow beautifully, even without the use of fertilizer. If you have gone to a decision to boost its appearance, it will flourish into a beautiful and compact bush of flowers.

Knockout Roses Care and Maintenance Tips

Before you start growing these beautiful flowers, you have to know that these flowers are easy to grow and need too much of your care. As a plus, they do not easily catch diseases, making them an excellent plant for your garden.

● Place Organic or Chemical Food

For caring for these cheerful flowers, you have to feed them with an excellent organic or chemical rose food to make them have a good kick start. So, you keep them well fed up to the end of the blooming season; you’d have attractive and beautiful rose bushes on your lawn. 

● Requires Minimal Trimming

However, when the time comes in which they’d be in bad shape, minimal trimming now and then is a good move. Admittedly, flowers will be right back to their usual form in no time. You can have them again in a great appearance together with a lovely bloom.

● Perform Pruning

Besides, if you do not prune the rose to adjust the height, they can grow as 3 to 4 feet wide and 3-4 feet tall. Hence, when you decide to do pruning, you need to do that during early spring. This time is highly recommended because your roses can attain the top performance and grow into magnificent shrubs by that time.

Factors Need to Consider While Choosing the Best Fertilizer for Knockout Roses:

Don’t rely on something that dubs itself as the best. Also, you just cannot opt for a certain product without considering the following factors. Here are some of the factors to consider before you choose the right fertilizer for your roses.

NPK Ratio

For you to have a good fertilizer, a well-balanced NPK ratio is essential. NPK means nitrogen, phosphorus, and potassium, for which these three chemical elements are primary elements of a fertilizer. 

Due to the different plant varieties, there should be a right blend of the three. Especially on roses in which they react best on even formulations.

Organic or Non-Organic Type

In choosing a fertilizer, you have to be keen in choosing for either organic or non-organic ones. Each type has its advantages, so you’d surely have a tough time picking what to pick. But, it will be mainly due to your preference as the user of the product.

Organic fertilizers will enhance the beauty of your roses as well as the soil where it is planted. The roots of your flowers will grow stronger and healthy. On the other hand, non-organic fertilizers will make great food but have only a little help on the soil. But on the bright side, it will protect your plants from insects and diseases.

Rotating the Type of Fertilizer

One factor that you have to consider is the rotation of fertilizer that you are using. It is because if you use the same chemicals on an area of the soil, it may lead it to poor quality. Proper rotation of chemicals will lessen the risk of adverse effects. However, organic fertilizers are best if you want to improve soil quality.

Frequently Asked Questions

1. How can I make my knockout roses bloom more?

Garden lovers would surely want to see their knockout flower to go in full and more prominent blooms, so for you to do that, you should take good care of your favorite flowers.

First, you have to let them drink 1-inch of water per week. If the season is hot, you can apply more than that measurement. You have to be careful enough of overwatering because it may lead you to a dying bush of roses. 

Removing insects is also one of the contributors to a healthy garden. These insects may spread harm to your plants and will affect their growth. Also, do not forget to take away deadheads so that you’d attain a good bloom.

2. Why did my roses stop blooming?

There are a few reasons why your flowers stopped blooming. It may be because of insect infestation, lack of feeding, or you overwatered it. But, the highest percentage is because of feeding your knockout roses the wrong fertilizer. So, you should be knowledgeable about when and how to fertilize them.

3. Do you need to water knockout roses every day?

Watering of your flowers will primarily depend on the weather that you are in as of the moment. For example, if you have these roses in summer, you need to water them every two to three days, depending on the decency of heat. 

If it is warm and dry weather, you just have to let them take a sip of water once a week.

4. Are coffee grounds good for knockout roses?

Indeed, roses love coffee grounds, but then, it is not advisable to sprinkle them into the plants. They may contain various minerals, but too much of these can be detrimental to the roses, which will eventually kill them.


At this point in the article, you’d probably know that good fertilizer will yield great roses. We genuinely hope that we helped you pick the best fertilizer to attain a magnificent bloom. Good luck!