If you are wondering what else do flowers need other than the sun and water, the answer is fertilizer!
But beware, feeding the wrong plant food or feeding too much can ruin the flowers.
If you to enjoy the colorful blooms, you must remember plants need lots of energy and nutrients to grow flowers.
Fertilizers are needed for both potted flowers and those growing in the garden bed.
This buying guide has detailed information about the best fertilizers for flowers and recommends the best flower fertilizers.
We get commissions for purchases made through links in this post.
Best Fertilizers for Flowers
The best fertilizers for flowers are all-purpose fertilizers that contain the necessary macronutrients nitrogen, phosphorus, and potassium indicated as NPK such as 24-8-16 or 12-4-8. Overly high phosphorus values in fertilizers are not needed for flowers to bloom. Fertilizers for flowers need to be higher in nitrogen (N).
The best fertilizers for flowers are:
- Best Overall Flower Fertilizer – Blossom Booster by Jack’s Classic
- Best Instant Flower Fertilizer – Water Soluble Bloom Booster by Miracle-Gro
- Best Organic Flower Fertilizer – Bud and Bloom Booster by Dr. Earth
Best Fertilizers for Flowers
Table of Contents
Phosphorus for Plant Blooms
According to the University of Massachusets Amherst, fertilizers sold as bloom boosters with overly high phosphorus such as 15-30-50 or 10-30-20 are missing the point.
Only agricultural soils depleted of phosphorus would need such a high concentration.
Non-agricultural soils generally have a balanced NPK ratio present already.
High nitrogen is more important the university concludes as it is needed for photosynthesis, green leaf development as well as fruiting and seed development.
But all of the 3 need to be present.
Phosphorus is indeed needed for flowering but also to transport energy through the plant and its roots.
Lastly, potassium supports photosynthesis and is needed for flowering, seed growth, and the general growth of a plant.
Best Flower Fertilizers
The below fertilizers are fertilizers I have used in the past that work great.
But as mentioned all of them contain probably more phosphorus than you will ever need depending on the soil you are using.
Blossom Booster by Jack’s Classic – Best Overall Flower Fertilizer
This is an all-purpose flower fertilizer and can be used for flower beds, hanging baskets, or pots.
This flower fertilizer is formulated for indoor and outdoor use to enhance the bloom size, number, and color.
The manufacturer also provides a measuring scoop with this plant food for precise measurement of the fertilizer.
The macronutrients are present in the ratio of 10-30-20; however, it also contains essential micronutrients for better root and leaf growth.
As a water-soluble fertilizer, it can feed your flowering plants through the soil or leaves, depending on your preferred method of feeding.
I prefer using this plant food as a foliar spray, but you have to make sure all leaf surfaces are covered with the fertilizer.
To increase the number of flowers, the manufacturer recommends using it during the budding stage.
Generally, this fertilizer should be applied every 1 or 2 weeks in the active growth season.
Pros
- No risk of burning if used according to directions
- Can be used for flowers, vegetables, and berries
- Detailed dosage instructions and a measuring spoon is provided by the manufacturer
Cons
- It’s a strong fertilizer, and overdosage can kill young flowering plants
View this incredible product here.
Water Soluble Bloom Booster by Miracle-Gro – Best Instant Flower Fertilizer
Oftentimes the roses and other flowers in your garden start wilting and need an instant dose of nutrition. A good quality instant fertilizer can help prolong the blooming period for such plants.
This flower food has been manufactured to serve as instant food for the plants as it is water-soluble.
It will not only improve the color of the blooms but also increase the number of blooms on a single plant.
The nutrient ratio in this bloom booster is 15-30-15. It’s rich in phosphorus, which makes it an excellent plant food for blooming houseplants.
Miracle-Gro recommends repeating the application after 7 or 14 days, especially if your plant is still in the recovery stage.
You can also add this fertilizer at the time of planting to help the plant establish itself in the new environment before the blooming phase begins.
For indoor potted plants, mix ½ teaspoon in one-gallon water. For outdoor potted plants, use 1 ½ tablespoon of this bloom booster in 1 ½ gallon of water.
For large garden beds, you can adjust the fertilizer ratio depending on the size of the area.
You can feed this fertilizer using a water can or the Miracle-Gro garden feeder.
I would highly recommend using this bloom booster for all the flowers in your garden before and during the bud formation and blooming period to enjoy a long blooming season.
Pros
- Instant feeding for instant results
- Will not burn the flowers or foliage if you follow the instructions for feeding
- Formulated especially for flowering plants with high phosphorus content
- It can be used for all types of annuals, perennials, container flowers
- Two methods for feeding
- Easy to apply as a water-based solution
Cons
- Customers received torn packages with missing scoops
- Difficult to pour the fertilizer from the bag
Learn more about this fertilizer here.
Bud and Bloom Booster by Dr. Earth – Best Organic Flower Fertilizer
If you want a single fertilizer for all the rhizomes, tubers, and bulbs in your garden, invest in this product.
The biggest advantage of this flower fertilizer is that it’s 100% natural and organic.
It’s created by blending natural ingredients like feather meal, fishbone, and alfalfa meal.
Dr. Earth is committed to introducing sustainable gardening approaches; this fertilizer is created using up-cycled food-grade waste products.
Although it’s rich in nutrients, it does not contain synthetic chemicals, GMOs, or chicken manure. You can use this fertilizer for any growth stage, and the 4 lbs package will last for several months.
This fertilizer also has the TruBiotic, which helps in reviving the soil using the beneficial microbes. These microbes ensure long-term benefits for your soil and plants.
The NPK ratio of this fertilizer is 3-9-4. The unique combination of macronutrients and other natural ingredients in this fertilizer promises strong root and flower growth.
It ensures your flowering plants receive a consistent supply of phosphorus.
This fertilizer is OMRI (Organic Materials Review Institute) certified for organic use.
Pros
- 100% organic and rich in natural ingredients
- Long-lasting nutrition
- It contains mined potassium sulfate ad soft rock phosphate
- Enriched with soil microbes
- Improves the plant tolerance against droughts
- Can be used for flowering plants, Citrus, and fruit trees
- Helps in root and flower development
- Does not cause growth spikes
Cons
- Has a strong smell
- Can lead to fungus gnats infection
- Does not dissolve in water
You can buy this fertilizer by clicking here.
Super Bloom by Scotts – Best Phosphorus based Fertilizer
The most important element for flowering plants is phosphorus. Feeding with a phosphorus-rich fertilizer at the right time can result in bursts of blooms within your garden.
This fertilizer has an NPK analysis of 12-55-6.
The word super in the name of this fertilizer definitely has meaning because this plant food contains the highest percentage of phosphorus compared to all other fertilizers in this list.
This water-soluble plant food also contains chelated iron.
Keep in mind that even the best fertilizer can only work if you follow the application rates recommended for it – this fertilizer should be reapplied every 1 or 2 weeks.
This fertilizer can be used for all varieties of flowers growing in raised beds, containers, or any other outdoor area.
This fertilizer is rich in phosphorus, but if you want to protect the flowers from fertilizers burns, I would suggest applying the fertilizer as directed by the manufacturer.
Another tip is to water the soil before adding the plant food.
Pros
- Highest phosphorus content
- Easily dissolves in water to create a water-based plant food mixture
- For potted and in-ground flowers
Cons
- Customers received fertilizer packages with a broken seal
Want to make a purchase? Click the link here to avail of this product.
Rose and Flower Care by BioAdvanced – Best Granular Flower Fertilizer
If you want to do a little something extra for your favorite flowers in the garden, you can feed them with this fertilizer.
It’s a 3-in-1 fertilizer – it works as a fertilizer, insect killer, and disease controller.
This granular fertilizer is designed to encourage not only strong roots and blooms but also to get rid of most pests and diseases in the garden.
The best feature of this multipurpose fertilizer is that a single application will last for 6 weeks.
You can use it for several diseases. The top ones are powdery mildew, black spots, rust, and blight.
To apply the fertilizer, sprinkle the granules near the base of the plant, water the soil to help the granules blend in.
For optimum results, repeat the application every 6 weeks in spring, summer and autumn.
Pros
- Rainproof fertilizer
- Can also control bugs and disease that might hinder blooming
- Suitable for all flowers and flowering shrub types
- Ready-to-use product as no dilution is required
- A single bottle can treat 32 roses
Cons
- Not recommended for potted flowers
- Customers complained that the bottle is difficult to open
Purchase this fertilizer here.
Rose and Flowering Formula by Neptune’s Harvest – Best for Budget Flower Fertilizer
This liquid plant food will increase the volume of flowering plants. The NPK ratio is 2-6-4.
In addition to the blooms, this fertilizer will also enhance the drought tolerance of your flowering plants.
This fertilizer is created using humic acids, fresh fish, seaweed, and yucca extract. All these ingredients improve the overall vigor and flowering capabilities of your plants.
This fertilizer should be used twice – initially at bud formation and later when blooming starts. You can repeat the application every 1-2 weeks.
We have categorized this fertilizer as best for budget because a single bottle can make about 64 gallons of fertilizer.
You can apply this fertilizer directly to the soil or as a foliar feed. Make sure the top and bottom sides of the leaves are covered with fertilizer for best results.
Since it’s diluted in the water, there are very few chances of overfeeding your plants. But I still recommend following the dosage instructions by the manufacturer.
Always prepare a fresh batch of fertilizer solution before application, avoid storing excess fertilizer.
The only thing that bothers most gardeners about this fertilizer is the smell; however, there is nothing to worry about as the smell fades after a day or two of application.
Pros
- Plants will have more buds and flowers
- Organic
- Sprayer friendly liquid fertilizer
- Simple to use with natural ingredients and effective results
- Great for flowers and foliage
- Can be applied to indoor and outdoor flowers
Cons
- Not OMRI listed
- Costumers received leaked bottles with broken lids
Buy this incredible fertilizer here.
Premium Water Soluble Plant Food for Flowering Plants by Proven Winners – Best Starter Flower Fertilizer
This fertilizer is easy to use with the measuring scoop and the handle.
I would highly recommend using this fertilizer for newly planted, young flowering plants that need a boost of nitrogen as this fertilizer is rich in nitrogen.
The NPK ratio for this flower fertilizer is 24-12-17.
Detailed application rates based on container size are printed on the fertilizer tub. It’s important to follow these rates if you want to avoid burning your plants.
This fertilizer is designed to improve plant performance, increase plant life and encourage better blooms.
It is great for heavy bloomers that grow fast as it can meet their nutritional demands.
This fertilizer should be applied after mixing it in water to help deliver the nutrients faster.
Pros
- Has high nitrogen for strong root development that leads to better blooms
- Fast-acting fertilizer
- Can be used for hanging baskets, containers, or landscape beds
- Great for annual flowers
- Can also be used for hydroponic flower gardening
- Safe for use around pets
Cons
- Not organic
- Expensive for large applications
Buy this fertilizer here now.
Rose and Flower Mix by Down to Earth – Best Rose Flower Fertilizer
Down to Earth has a wide range of natural products, including organic fertilizers, compost, and soil amendments.
If you love feeding your roses with natural fertilizers, this might be the best fertilizer. You can use this natural product for any type of flowers growing from bulbs.
With the NPK ratio of 4-8-4, the Rose and Flower mix is the ideal fertilizer to achieve beautiful blooms that have rich colors and fragrance.
It has a healthy blend of nitrogen, phosphorus, potassium, plus other trace minerals that cause vigorous plant growth.
This fertilizer can be used at the time of planting new flowers or when new growth appears on the already planted ones.
I like using this fertilizer for other edible plants and vegetables in my garden because it’s OMRI listed and is safe for all types of plants.
Pros
- Great for spring and summer bulbs
- The extra phosphorus will produce vibrant flowers
- Recyclable cardboard box
- OMRI listed
- Stand-alone fertilizer for flowers that can be used throughout the season
- Enriched with fish meal, alfalfa meal, kelp, and blood meal
Cons
- Customers complained about receiving packages that were already opened
- Not for indoor flowers because of the smell
Buy this incredible fertilizer here.
Types of Fertilizers for Flowers
Liquid Fertilizer
Two types of liquid fertilizers are sold in the market. The first one is concentrated liquid plant food that should be diluted in water before application.
You can also buy powder fertilizer that is mixed with water to create a liquid plant food solution. Always follow what the manufacturer says in terms of dilution or mixing rates.
You can apply liquid fertilizer in two ways. You can feed them directly to the soil or use them as a foliar spray.
They do not last long in the soil, and most of them can feed the plants for 1 or 2 weeks only. For this reason, liquid fertilizers need to be reapplied very often.
This type of fertilizer is absorbed fast and easily. So plants will show quick results. They are the perfect choice to save a wilted or diseased plant.
Winner: Rose and flowering Formula by Neptune’s Harvest
Granular Fertilizer
You can add a granular fertilizer to the soil using a spreader or by scattering the granules on the soil surface.
Do not let the granules sit on the soil surface; instead, mix them well in the top layer of soil so the roots have better access to the fertilizer. For best nutrients distribution, water the soil before and after adding the granules.
Did you know that granular fertilizer will stay the longest in your soil; some varieties can stay there for up to 9 months.
Winner: Rose and Flower Care by BioAdvanced
Organic Fertilizer
Do not rely on the word organic printed on the fertilizer package because there is a chance that the product might not be truly organic. The best organic fertilizers are the ones certified by OMRI.
Ingredients like earthworm castings, kelp, and secondary nutrients enhance the overall efficiency of organic fertilizers.
They will not show dramatic results, but at the same time, they do not burn your plants.
Organic fertilizers fall in the category of slow-release fertilizer as the nutrients are released within a few weeks or months.
If you want quick results for your plants, go for a good quality synthetic plant food in liquid or granular form.
But if you want to repair your soil using natural ingredients, my recommendation is organic fertilizers because chemical fertilizers do not contribute to soil fertility.
Organic or natural fertilizers take a long time to break down nutrients; therefore, add them to the soil a few months before planting or sowing seeds.
They feed the plants and the living microorganisms inside the soil.
Organic fertilizer might be costly compared to their synthetic alternatives, but they offer more long-term benefits.
Patience is important if you want to become a true organic gardener but believe me, the final results are worth the effort, extra cost, and wait.
Winner: Bud and Bloom Booster by Dr. Earth
Fertilizing Your Flower Garden
All houseplants need sunlight, water, and nutrition to thrive. But the real question here’s the type of nutrition is required for flowering plants.
The NPK ratio of the fertilizer will help you in selecting the right flower fertilizer.
Ornamental and flowering plants love all three nutrients, nitrogen, phosphorus, and potassium.
The N is needed for lush green leaves, P is needed for growing strong roots and fluffy blooms, and lastly, K is needed for the overall growth of your houseplants.
Many gardens start their gardening journey with ornamental plants because they want to enjoy the fragrance and colors of beautiful flowers.
But they often struggle with feeding their flowers at the right time with the right fertilizer.
The time of fertilizing flowers depends on two factors:
- Type of flower – perennial or annual
- Growth stage – new or established plant
The best time to feed annual flowering plants is while preparing the soil for the garden bed or pot.
Reapply plant food after 6 or 8 weeks. You can even feed them in late August.
Young perennials should be fed at the time of planting.
Established Perennials should be fed once they break dormancy and start growing in the spring season.
Both varieties should be fertilized regularly during active growth.
However, remember that annual plant varieties need more food as compared to perennials, so prepare a fertilization plan accordingly.
If you are growing flowers from bulbs, fertilize them as you notice new growth in spring or summer.
The first step before adding any flower plant food is watering. Water your plants as you would do on a regular day to make sure the soil is moist.
Skipping this step makes the root vulnerable to chemical or fertilizer burns because dry plants absorb the nutrients faster.
If your flowering plant is in the seedling stage, feed it lightly with a gentle solution, usually at half strength.
This is because the roots are tender at this stage and cannot handle a strong product.
Most gardeners do not want their beautiful plants to face nutrient deficiencies, so they forget about over-fertilizing. Too many nutrients are also not good for the plants.
If your soil has extra nitrogen, your plant will produce more leaves compared to flowers or fruits.
Phosphorous is essential for blooming, but too much of it can hinder the absorption of micronutrients. Even excess potassium is not good for the plants.
Flowers growing in pots need more food because they do not have other sources of nutrition.
You might have to feed them every week to grow the healthiest and colorful flowers. Always feed the plants early morning or late in the evening.
Generally, flower beds are fertilized from spring to late summer, but you should avoid feeding in fall and winter.
Watering or excessive rain can wash away the essential nutrients from the soil. You should give another dose of fertilizer to revive the nutrient content.
If you are wondering how often you should fertilize the flowers, it entirely depends on the type of fertilizer you are using.
Liquid fertilizers need to be applied more frequently compared to other types.
You might not find the perfect plant food on the first try but keep experimenting because trial and error is part of your gardening journey.
Conclusion
Adding fertilizers will boost the soil to help you achieve bigger and colorful blooms.
But what fertilizers you choose for your flowering plant really matters.
All the recommendations for the best flower fertilizers in this article are trusted and tested by expert gardeners.
They give impressive results for annual and perennial flowers.
Daniel has been a plant enthusiast for over 20 years. He owns hundreds of houseplants and prepares for the chili growing seasons yearly with great anticipation. His favorite plants are plant species in the Araceae family, such as Monstera, Philodendron, and Anthurium. He also loves gardening and is growing hot peppers, tomatoes, and many more vegetables.
Last update on 2024-12-21 / Affiliate links / Images from Amazon Product Advertising API