Best Rose Food For Knockout Roses of 2024: Top 6 Picks

By Harry RamosLast update: 2024-04-21

Knockout roses are some of the most popular and beloved flowers in many gardens around the world. But in order for them to bloom to their fullest potential, they need the right soil and balance of fertilization. In this article, we review the 6 top options and include a buying guide so you can find the best rose food for knockouts!

Here are the best rose food for knockout roses you can buy in 2024:

  • Fast Acting: Jobe’s Organics 09423
  • Best For Insect And Disease Control: BIOADVANCED 701110A
  • Slow Release: Scotts 200950
  • Best For Abundant Blooms: Miracle-Gro 2000221
  • Best For Bigger Blooms: Espoma RT4
  • Best For More Vibrant Blooms: Bloom City 3-2-4 Rose & Flower Natural Plant Food
6 Best Rose Food For Knockout Roses
Fast Acting
Jobe’s Organics 09423
    Best For Insect And Disease Control
    BIOADVANCED 701110A
      Slow Release
      Scotts 200950
        Best For Abundant Blooms
        Miracle-Gro 2000221
          Best For Bigger Blooms
          Espoma RT4
            Best For More Vibrant Blooms
            Bloom City 3-2-4 Rose & Flower Natural Plant Food

              Fast Acting: Jobe’s Organics 09423

              Jobe’s Organics 09423
              Jobe’s Organics 09423
              Pros
              • Help plants absorb nutrients rapidly – fast-acting formula
              • Eco-friendly - OMRI listed for organic gardening by USDA
              • Easy to control the dose - a granular form
              Cons
              • The fertilizer has a bad smell

              We were pleasantly impressed with Jobe's Organics 09423 for its fast-acting formula.

              This fertilizer exclusively contains Job's Biozome, a consortium of 3 microorganisms that includes a unique species of Archaea. This ingredient helps speed up the digestion process of nutritious materials, so plants can absorb more rapidly and give faster results.

              Unlike other fast-acting fertilizers, this one is OMRI listed for organic gardening by USDA, so you can use it with confidence.

              Made in a granular form, this fertilizer is easy to apply because you can control the dose better and there's no risk of spillage.

              Jobe’s Organics 09423 Specifications

              Size

              16 lbs.

              Fertilizer Analysis

              3-5-3

              Highlight Features

              fast-acting formula

              OMRI listed for organic gardening by USDA

              Verdict

              The Jobe’s Organics 09423 is a great choice for knockout roses. Its fast-acting formula helps nourish plants quickly and its OMRI listing ensures quality.

              Best For Insect And Disease Control: BIOADVANCED 701110A

              BIOADVANCED 701110A
              BIOADVANCED 701110A
              Pros
              • Insect and disease control – contain fungicide
              • Offer long-lasting protection up to 6 weeks - systemic rainproof protection
              • Safe & reliable - a science-based formula
              Cons
              • Wish it had a measuring cup

              If your knockout rose garden is often attacked by diseases and insects, the BIOADVANCED 701110A is surely a lifesaver!

              This is a science-based solution with three main functions:

              • Control diseases like Southern Blight, Rust, Powdery Mildew, and Black Spot.
              • Kill multiple harmful insects. Such as Leafhoppers, Aphids, Japanese Beetles, and more.
              • Promote strong roots and beautiful blooms.

              It uses fungicide, which is eco-friendly and toxin-free, while the systemic rainproof formula prolongs the protection up to 6 weeks per application.

              Each 4-pound bottle is enough to feed 32 roses, and the price is great.

              BIOADVANCED 701110A Specifications

              Size

              4.3 Pounds (4000ml)

              Fertilizer Analysis

              6-9-6

              Highlight Features

              contain fungicide

              systemic rainproof protection

              a science-based formula

              Verdict

              We find the BIOADVANCED 701110A to be absolutely invaluable for keeping knockout rose gardens from insects and diseases.

              Slow Release: Scotts 200950

              Scotts 200950
              Scotts 200950
              Pros
              • No need to feed frequently – slow-release formula, lasting up to 2 months
              • Easy to use – granular form
              Cons
              • No complaint

              The Scotts 200950 is a great product for any gardener seeking to nourish their knockout roses with a slow-release formula.

              This fertilizer provides a steady stream of nutrition over the course of a few months, including nitrogen, phosphorus, and potassium, to help promote strong, healthy roots and foliage.

              We particularly appreciate that it is easy to apply and that it doesn't have a strong odor.

              Scotts 200950 Specifications

              Size

              3 lbs.

              Fertilizer Analysis

              12-4-8

              Highlight Features

              slow-release formula, lasting up to 2 months

              granular form

              Verdict

              The Scotts 200950 is a reliable slow-release fertilizer and a perfect choice for those gardeners who want to feed their rose plants with no risks of overfeeding.

              Best For Abundant Blooms: Miracle-Gro 2000221

              Miracle-Gro 2000221
              Miracle-Gro 2000221
              Pros
              • Produce abundant blooms – the 24-8-16 ratio
              • Reliable - endorsed by the American Rose Society
              • Easy to apply with either a water can or Miracle-Gro Feeder
              Cons
              • A bit hard to open

              The Miracle-Gro 2000221is endorsed by the American Rose Society for its effectiveness in helping roses, and all flowers for that matter, to produce bigger and more beautiful blooms.

              After just a few days of use, you will see your roses are noticeably fuller and more vibrant. Soon after, they have even more blooms than before.

              As an added bonus, this fertilizer is easy to use, no matter whether you're an amateur or an experienced gardener.

              Miracle-Gro 2000221 Specifications

              Size

              1.5 lbs.

              Fertilizer Analysis

              24-8-16

              Highlight Features

              the 24-8-16 ratio

              endorsed by the American Rose Society

              Verdict

              The Miracle-Gro 2000221 really lives up to its name - we definitely recommend it if you want abundant blooms!

              Best For Bigger Blooms: Espoma RT4

              Espoma RT4
              Espoma RT4
              Pros
              • Encourage bigger blooms - Bio-tone microbes
              • Provide optimal growth - feather meal and pasteurized poultry manure
              • Versatile – the all-purpose formula
              Cons
              • The fertilizer has a strong smell
              • The bag could be sturdier

              The Espoma RT4 contains two organic ingredients – feather meal and pasteurized poultry manure – that work together to provide the nutrients needed for optimal growth and superior performance in rose flowers.

              It also contains Bio-tone microbes, which are beneficial to their healthy development and hence encouraging bigger blooms.

              The all-purpose formula means you can use this fertilizer on all types of roses, including established, new, and even indoor herb gardens.

              Espoma RT4 Specifications

              Size

              2.04 Pounds (4 Liters)

              Fertilizer Analysis

              4-3-2

              Highlight Features

              Bio-tone microbes

              feather meal and pasteurized poultry manure

              the all-purpose formula

              Verdict

              If you’re looking for an all-purpose fertilizer to produce bigger blooms in your roses, then we would certainly recommend the Espoma RT4. It’s easy to use, safe for the environment, and brings great results.

              Best For More Vibrant Blooms: Bloom City 3-2-4 Rose & Flower Natural Plant Food

              Bloom City 3-2-4 Rose & Flower Natural Plant Food
              Bloom City 3-2-4 Rose & Flower Natural Plant Food
              Pros
              • Promote more vibrant blooms - a combination of essential nutrients and minerals
              • Help balance soil’s pH level – containing fulvic, humic, and dolomitic
              Cons
              • It’s hard to mix unless you have proper tools

              When it comes to finding the perfect fertilizer for more vibrant blooms, the Bloom City 3-2-4 Rose & Flower Natural Plant Food should be at the top of your list.

              It contains a powerful combination of essential nutrients and minerals that encourages stronger roots and more vibrant blooms, so that your plants can reach their full potential without risking their health.

              The fertilizer also contains a blend of three types of humic acid—fulvic, humic, and dolomitic—which work together to increase nutrient availability and help balance the pH levels of soil.

              This ensures that your plants are getting the vitamins and minerals they need for optimal growth, and can even help plants already suffering from nutrient deficiencies bounce back quickly.

              Bloom City 3-2-4 Rose & Flower Natural Plant Food Specifications

              Size

              32 Ounces (0.94 Liters)

              Fertilizer Analysis

              3-2-4

              Highlight Features

              a combination of essential nutrients and minerals

              containing fulvic, humic, and dolomitic

              Verdict

              The Bloom City 3-2-4 Rose & Flower Natural Plant Food is a fantastic choice if you want your flowers to reach their full potential. Its unique formula helps promote stronger roots and more vibrant blooms for a truly stunning garden.

              How To Choose The Best Rose Food For Knockout Roses?

              Type Of Fertilizer

              When choosing the right fertilizer for your knockout roses, it’s essential to understand the different types of fertilizers that are available and then determine what your roses need.

              Inorganic fertilizers, such as those made from manufactured chemicals, provide a quick boost of nutrients but can build up in the soil over time. In turn, they carry risks of causing harm to the surrounding environments, your health, and your pets.

              Organic fertilizers, on the other hand, are made from natural sources such as plant, animal, and mineral materials, and provide a slower release of nutrients over a longer period of time.

              Fertilizer’s Ingredients & NPK Rating

              For knockout roses, the best fertilizer will depend on the type of soil, the amount of sun, and the particular needs of the rose.

              For instance, if you are growing in sandy soil with limited organic matter, a slow-release fertilizer that contains nitrogen, phosphorus, and potassium is ideal.

              If your soil is rich in organic matter, opt for blood meal or alfalfa meal, which are high in nitrogen but low in phosphorus and potassium.

              The fertilizer’s ingredients also depend on the growing stage of your rose plants.

              For newly planted roses, a complete fertilizer with a high phosphorus ratio, such as 18-24-16, may be beneficial.

              When the plants are established, a nitrogen-rich fertilizer should be used for the first application, along with Epsom salts to encourage new cane development and lusher growth.

              For 4-5” long shoots, a slow-release fertilizer can be added.

              Additionally, finding a fertilizer that contains additional essential micronutrients (such as iron, magnesium, and zinc) can help strengthen plants’ abilities to resist disease and increase crop yields and overall quality.

              When in doubt, use a balanced fertilizer such as a 10-10-10 or a 20-20-20 blend for best results.

              Which Brands Make The Best Rose Food For Knockout Roses?

              Jobe’s Organics

              Jobe's Organics is dedicated to organic and eco-friendly fertilizer products. They offer a wide range of high-quality fast-acting organic fertilizers that bring guaranteed results. With Jobe's, you get less work and more results!

              Miracle-Gro

              Miracle-Gro is a good brand and here's why:

              • Their fertilizers are safe to use and very reasonably priced
              • They provide an enormous amount of nitrogen for plants so that they grow bigger and stronger
              • The formula is guaranteed not to burn when used as directed.

              Miracle-Gro is also a great choice for organic gardens, as they offer specially formulated organic fertilizers.

              FAQs

              Do I need to fertilize my knockout roses?

              Yes, you should fertilize your knockout roses in the spring and early summer, following the instructions on the fertilizer label.

              How often do knockout roses need to be fertilized?

              Knockout roses should be fertilized around three times a year, specifically in the spring after they leaf-out, and again after their first flush or blooms. This will help give them an extra boost and ensure they are getting the nutrients they need to thrive.

              How do I make my knockout roses thicker?

              To make your knockout roses thicker, you should prune them over three years for major leggy growth. Additionally, you should use a balanced fertilizer with high nitrogen and low phosphorus and potassium, such as blood and alfalfa meal, and apply about a cup or so each time.

              How do I make knockout roses bigger?

              To make knockout roses bigger, it is important to plant them in rich and well-draining soil in a sunny location, provide consistent watering, and use proper garden maintenance techniques, such as pruning and fertilizing.

              Can I give knockout roses too much fertilizer?

              It’s not recommended giving knockout roses too much fertilizer because this can cause chemical burn and make your roses look unhealthy. It is important to use the proper amount and follow the instructions on the fertilizer label.

              Conclusion

              That’s everything for this article!

              We have looked at some of the best rose food for knockout roses that you can use to give your flowers all the nutrients they need.

              With a bit of research and knowledge on what rose food is right for your plants, you should be able to keep them looking their best and ensure they remain healthy all year round.

              However, if you ever find yourself in doubt or need further information, do not hesitate to contact a professional gardening service - they will always be happy to help!

              I’m Harry Ramos, who's crazy about all things green. I’m here to share some experience in my gardening adventure and how to choose the best products for your garden. Let's dig in, get our hands dirty, and celebrate the simple, earthy pleasures of the garden together!


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