10 Best Fertilizer for Gardenias 2021 [Top Picks & Guide]

Gardenias are prized for their beautiful, creamy-white blooms with a sweet fragrance. But without fertilizer, you can’t think about the desired blooms and fragrances that make your neighbors jealous.

So, if you want a bushy gardenia with dark green, glossy leaves, and long-lasting blooms, you should feed a good fertilizer to your plant. 

But choosing the best fertilizer for gardenia is a little bit tricky because of its complex biology. There are hundreds of fertilizers available in the market today. All are not good for gardenias.

Then what is the best fertilizer for gardenias?

Gardenias are acid-loving plants like Azaleas and Camellias, So, in a nutshell, the best gardenia fertilizers are the specially formulated fertilizers for the acid-loving plants that have a balanced NPK ratio with required micronutrients and don’t contain any toxic chemicals.

For your convenience, In this article, I have reviewed the 10 best fertilizers for gardenias that help you to pick the right fertilizer for your gardenias.

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In a Rush? Here is the best of the best fertilizer for gardenia plants that you can buy right now with confidence-

Best Fertilizer for Gardenias- Comparisons

Gardenias FertilizerNPKFormTypePrice
Dr. Earth 703P Organic Acid Fertilizer4-5-4GranularOrganic
Jobe's Azalea, Camellia & Rhododendron Fertilizer Spikes9-8-7SpikeSynthetic
Miracle-Gro Plant Food for Acid Loving Plants30-10-10PowderedSynthetic
Jobe’s Organics (08281) Fertilizer6-1-1PowderedOrganic
Espoma HT50 Holly Tone Fertilizer4-3-4GranularOrganic
J R Peters Jacks Classic Acid Fertilizer17-6-6PowderedSynthetic
Nelson Acid Loving Plant Food9-13-11GranularSemi-Organic
Gardenia Fertilizers by Plants for Pets3-1-2LiquidOrganic
Sunniland Azalea , Camellia & Gardenia Fertilizer8-4-8GranularOrganic
Lilly Miller Rhododendron Evergreen And Azalea Food10-5-4GranularOrganic

Best Fertilizer for Gardenias- Reviews

1.Dr. Earth 703P Organic Acid Fertilizer

Dr. Earth 703P Organic 4 Azalea/Camellia/Rhododendron Acid FertilizerAre you looking for the best organic fertilizer for gardenias? Here is the Dr.Earth 703p Acid fertilizer. It is an OMRI listed fertilizer for organic gardeners that is specially formulated for acid-loving plants.

According to the NPK ratio, it contains 4% nitrogen,5% phosphate, and 4% potash and you know nitrogen is the main component of chlorophyll that helps you to get lush green gardenias plant, higher phosphate encourage the plant to blooms and potash is important for overall plant health, and long-lasting blooms.

Good news; the total amount of nitrogen of this DR.Earth fertilizer has been coated for slow release. Slow-release nutrients release slowly and feed your plant continuously.

Moreover, it also contains some other macro and micronutrients but the manufacturer didn’t mention their percentages. Then how could I know that it contains some other nutrients?

From the label of the fertilizer, it enriches with feather meal, cottonseed meal, alfalfa meal, fishbone meal, kelp meal, and kelp flour. All are the organic source of essential plant nutrients including nitrogen, phosphorus, potash, calcium, iron, manganese, and so on. 

So, you don’t need to worry about the major and minor nutrient deficiency like chlorosis, yellow veins, if you feed it to your gardenias.

The best parts of this natural fertilizer are-

It has a probiotic formula. That means it contains some beneficial soil microbes and mycorrhizae fungi as the non-plant food ingredients that promote soil health, root growth, and make the plant disease resistant.

Also, it has 11% humic acid for protecting the gardenia plants from different types of environmental stress like water and heat stress.

Sprinkle 2 cups of 1-inch trunk diameter for inground gardenia or 2 tablespoons per gallon of potting mix for potted gardenia, mix with the surface soil gently, and water the plant. Repeat the application after 1-2 months. Read the label for the dosages of new plantings.

 

2.Jobe’s Azalea, Camellia & Rhododendron Fertilizer Spikes

Jobe's Azalea, Camellia & Rhododendron Fertilizer SpikesIf you want an easy-to-use fertilizer for your in-ground and potted gardenias, you may like the best spike fertilizer for gardenias; no need to pre-measured, take a spike, and push into the soil. 

Sounds simple, right? Now let’s analyze the fertilizer-

This fertilizer is specially formulated for acid-loving plants such as azalea, camellia, rhododendron, gardenia, and hydrangea.

As the plant food, it contains 9% nitrogen,8% phosphate,7% potash, less than 7% chlorine, and an adequate amount of calcium, magnesium, and sulfur. You know all the nutrients are essential for bushy dark green gardenias with strong roots and robust and beautiful blooms.

Sad but true it is poor in micronutrients. You can overlook it if the soil quality is good enough. But the good news; A small portion of the containing nutrients is coated for slow releases that can feed gardenias slowly and continuously as well as instant feeding.

All the nutrients are derived from some toxic-free and ammonium(good for acidic soil) riched compounds such as ammonium phosphate, ammonium nitrate, and potassium chloride. As you saw, the nutrients enrich with ammoniacal nutrients that don’t increase the soil pH.

The best thing about the spike fertilizer; It comes with a ready to apply spikes and has a minimum chance of runoff with surface water.

To feed this slow-release fertilizer-

Simply push 1 spike per foot diameter of the plant into the one inch below the soil and water the plant thoroughly. Feed this fertilizer once or twice per month.

 

3.Miracle-Gro Plant Food for Acid Loving Plants

Miracle-Gro Plant Food for Azaleas, Camellias, and RhododendronsMiracle-Gro Plant food for acid-loving plants is the best water-soluble fertilizer for gardenias that feeds the plant instantly and it is also formulated only for acid-loving plants including gardenias, azalea, blueberries, camellia, hydrangea, orchid.

According to the fertilizer analysis, it has 30% nitrogen,10% phosphate, and 10% potash. As you saw, it contains a heavy amount of nitrogen that promotes foliar growth, makes the plant bushy with green and glossy leaves, and keeps the soil acidic for a long time.

On the other hand, the adequate amount of phosphate and potash help the plant to produce more robust blooms and make the plant strong and resistant.

Moreover,it also contains 0.02% boron,0.07% copper,0.325% iron,0.05% manganese,0.07% zinc and 0.0005% molybdenum to fulfil the minor nutritional needs of gardenias.

And good news; most of the micronutrients are chelated form that means the nutrients have an organic coating for preventing them from any reaction. So, they always remain in the available form.

You know water-soluble fertilizer releases quickly and feed s the plant instantly. So, frequent application is required in the case of water-soluble fertilizer.

Moreover, the nutrients of this fertilizer are also derived from some safe and toxic-free ingredients.

Mix 1 tablespoon for outdoor gardenia and ½ teaspoon for indoor gardenia into a gallon of water and feed the solution once per 7-14 days.

 

4.Jobe’s Organics (08281) Fertilizer for Acid Loving Plants

Jobe’s Organics (08281) Holly, Azalea & Rhododendron Fertilizer for Acid Loving PlantsJobe’s Strikes again with Jobe’s Organics (08281) Fertilizer for Acid Loving Plants and you know, Gardenia likes acid fertilizer like azalea, holly, camellia, and rhododendron. Also this time it is enriched with micronutrients.

This fertilizer has a 6-1-1 NPK ratio. That means it contains 6% nitrogen,1% phosphate, and 1% potash. I know what you are thinking. About the poor NPK ratio, right? But it is not actually poor in NPK ratio. Let me explain-

You know water-soluble fertilizer feeds the plant instantly and it doesn’t contain anything for continuous feeding. As a result, the extra nutrients runoff with surface water. This fertilizer also comes with water-soluble powder but a small portion of nutrients of this fertilizer have been coated for slow release.

So, it can feed your gardenia for a longer period than other water-soluble fertilizers, though the NPK ratio is not heavy.

And good news; the fertilizer is derived from some organic compounds such as soy protein hydrolysate, kelp, soft rock phosphate, and sulfate of potash.

You will be happy to know; kelp is marine algae; a good source of macro and micronutrients and soy protein hydrolysate is the source of nitrogen and amino acid that makes your plant green and resistant.

But the best part of this fertilizer is-

It contains a natural blend of healthy Bacteria, Mycorrhizal fungi, and Archaea that is called biozome. It helps to improve the soil quality, plant growth, and make the plant resistant.

To feed this best gardenia fertilizer-

Mix 1 tablespoon into a gallon of water and apply it to the foliage and soil. Feed every 7-14 days for more blooms.

 

5.Espoma HT50 Organic Holly Tone Fertilizer

Espoma HT50 Organic 4-3-4 Holly Tone FertilizerEspoma HT50 is another best organic fertilizer for gardenias that is specially formulated for acid-loving plants, trees, and shrubs. Now let’s see what inside this holly tone fertilizer for gardenia-

As the primary nutrients, it contains 4% nitrogen,3% phosphate, and 4% potash, and 2.5% out of 4% nitrogen is water-insoluble nitrogen. You know water-insoluble nutrient dissolves slowly and feeds the plant continuously.

So, the perfect ratio of water-soluble and insoluble NPK makes the gardenia plant deeper green with more vibrant and fragrant blooms.

Besides NPK, it also has 3% calcium,1% magnesium,5% sulfur, and some other micronutrients for producing more robust and long-lasting blooms.

You will be happy to know that; all the nutrients are derived from some organic sources such as feather meal, bone meal, alfalfa meal, poultry manure, greensand, sulfate of potash, and elemental sulfur.

Bio-tone Microbes formula is the best part of this fertilizer. It contains some beneficial soil microbes for improving soil health as well as plants.

Also, it contains 1% humic acid that acts as a stress reviver and protects your gardenias from different kinds of environmental stress.

So, it can be said undoubtedly, this is one of the best plant food for gardenias today. But it can also perfect for some other plants such as amaryllis, andromeda, azalea, bayberry, blueberry, camellia, hemlock, holly, hydrangea, and so on.

To feed this Holly tone fertilizer-

Measure 1 cup per foot of branch spread for gardenia bush in the ground and 1 tablespoon per 3 inches pots. Sprinkle the pre-measured fertilizer around the base of the plant and water thoroughly.

 

6.J R Peters Jacks Classic Acid Special Fertilizer

J R Peters Jacks Classic No.1.5 17-6-6 Acid Special FertilizerJ R Peter Jack Classic Acid Special Fertilizer is acid-based fertilizer for gardenias that help the soil to reduce soil pH and make favorable growing conditions for gardenias. Good news; this fertilizer contains every required macro and micronutrient for gardenias.

As the macronutrient,this fertilizer contains 17% nitrogen,6% phosphate,6% potash,and 14% sulfur.All the most required nutrients for thriving, blooming, and developing the strong roots of gardenias.

Also, it contains 10.58% ammoniacal nitrogen out of 17% nitrogen. You will be happy to know, ammoniacal nitrogen acidifies the soil for a longer period.

As the micronutrient.it has 0.02% boron,0.05% copper,0.30% iron,0.05% manganese,0.05% zinc and 0.0009% molybdenum.

The best part of these micronutrients is; all are chelated nutrients and you know chelated nutrients have an organic coat that protects them from different reactions in the soil and always makes the nutrients available for plants.

This fertilizer comes with water-soluble powder that can feed your gardenias instantly and you can also feed this fertilizer to your other acid-loving plants such as hydrangea, blueberry, azaleas.

Want to produce creamy blooms with lots of sweet fragrance?

Mix 1 tablespoon for outdoor gardenia and ¼ teaspoons for indoor gardenia into a gallon of water and feed every 10-14 days.

 

7.Nelson Plant Food for All Acid Loving Plants

Nelson Plant Food for All Acid Loving PlantsNelson Plant Food is the best granular fertilizer that is specially formulated fertilizer for acid-loving plants including gardenias. It is a semi-organic fertilizer. That means this fertilizer enriches with some organic and synthetic compounds.

As the primary nutrients, it contains 9% nitrogen,13% phosphate, and 11% potash for promoting lush green, healthy roots and colorful blooms of your gardenias.

The best parts of this fertilizer, it has water-soluble nutrients for instant feeding and slow-release, water-insoluble nutrients for continuous feeding. And you will be happy to know, the slow-release nutrient is derived from an organic source that feeds your gardenias with no risk of burn or damage.

Sounds impressive, right? But there’s more-

It contains 3.42% ammoniacal nitrogen and you know ammoniacal nitrogen plays an important role to reduce pH and retain soil acidity for a long time.

Also, this fertilizer has 13% sulfur,3.2% iron, and 20% cottonseed meal. Cottonseed meal is the organic compound that improves the soil health, revives the plant stress by producing humic acids, and feeds some essential plant nutrients.

For feeding this semi-organic,slow-release granular fertilizer to your gardenias and other acid-loving plants-

Sprinkle 16 grams for 2.5 square feet area and 8.5 grams for the 1-gallon size of the container. Mix with the 1-2 inches surface soil and water the plant. Reapply after 1-2 months.

 

8.Gardenia Fertilizers by Plants for Pets

Gardenia Fertilizers by Plants for PetsGardenia Fertilizers by Plants for Pets is the best liquid fertilizer for gardenias. It is specially formulated only for gardenia to bloom.

It has 3% nitrogen for growth and development of foliage,1% phosphate for sturdy roots, and protecting the roots from root rot. and 1% potash for strong and healthy plants. Lastly, the balanced feeding of these NPK gives you a lot of beautiful blooms.

This fertilizer is perfect for all the varieties of gardenias such as flourish Golden Magic, Kleim’s Hardy, Cape Jasmine, Star Gardenia, and other varieties of the gardenia species.

Besides gardenia, it can also be applied to some other flowering plants of the Rubiaceae family.

This fertilizer comes in concentrated form. You need to dilute this solution for applying to gardenias.

Simply mix 2 teaspoons of liquid fertilizer into 2 cups of water and pour the solution around the base of the plants. Feed this fertilizer to your gardenia twice per month from March to October and feed once per month from November to December.

 

9.Sunniland Azalea, Camellia And Gardenia Fertilizer

Sunniland Azalea, Camellia And Gardenia Fertilizer

Do you need a fertilizer bag that can fulfill every need of the gardenia? Here is the Sunniland Azalea, Camellia, And Gardenia Fertilizer for you. It is another best fertilizer for gardenia bushes and other acid-loving plants that is fortified with all the essential plant nutrients.

According to the NPK ratio, this fertilizer contains 8% nitrogen,4% phosphate, and 8% potash and good news, it has both water-soluble and insoluble nutrients for quick and continuous feeding.

You know, gardenias love acidic fertilizer and you will be happy to know, it has 7% ammoniacal nitrogen out of 8% total nitrogen that helps the soil remain acidic.

Besides NPK,it also contains 1.20% magnesium,5.50% sulfur,0.02% boron,0.05% copper,0.5% iron, less than 6% chlorine,0.06% manganese,0.05% zinc and 0.0005% molybdenum for healthy gardenias and blooms.

All the nutrients are derived from some organic and toxic-free synthetic compounds such as ammonium sulfate, sewage sulfate, muriate of potash, sodium borate, etc.

Sprinkle 2-3 cups of fertilizer per 2-3 feet plant height, mix with the surface soil, and water the plant thoroughly.

 

10.Lilly Miller Rhododendron Evergreen And Azalea Food

Lilly Miller Rhododendron Evergreen And Azalea FoodLilly Miller Rhododendron Evergreen And Azalea Food is the last but not least fertilizer in my list. It is a natural ingredient containing fertilizer that is perfect for all acid-loving plants including gardenias.

This fertilizer has 10% nitrogen,5% phosphate,4% phosphate for dark green leaves, and colorful blooms. The good news, the nitrogen of this fertilizer is derived from four different sources including ammoniacal nitrogen.

It is a continuous release type fertilizer that means the nutrients release slowly and feed the plant continuously up to six weeks.

The best part of this fertilizer, it contains cottonseed meal. Cottonseed is the natural and organic ingredient that improves the soil quality, protects the plant from environmental stress, and feeds the essential plant nutrients to the plant.

So, you may pick this fertilizer and feed your gardenias regularly and get the green gardenias with lots of blooms.

 

How to Choose The Best Fertilizer for Gardenias?

If you want the best fertilizer for gardenia to bloom, then you should consider some points while choosing the fertilizer. Here is the buying guide that may help you to pick-

Fertilizer for Acid Loving Plants

Gardenia is an acid-loving plant. They can’t produce desired blooms if the soil pH is high. Also, they can’t uptake essential plant nutrients if the soil is not acidic. So, only the acid fertilizer can help the gardenia to take sufficient nutrients for thriving and blooming.

Ammonium forming fertilizer helps the soil pH lower for a long. So, before choosing the best gardenia fertilizer, make sure most of the nutrients are derived from ammoniacal ingredients.

Available Nutrients

Gardenias need nitrogen, phosphorus, and potassium more than other essential plant nutrients. Nitrogen need for foliar growth, phosphorus for blooms, and potassium for overall plant health, and the balanced ratio of the fertilizer only can give you a healthy plant with colorful blooms.

Moreover, the best fertilizer must have some other essential plant nutrients such as iron, zinc, copper, calcium, sulfur, etc.

Types of The Fertilizer

There many types of fertilizer available for acid-loving plants like gardenia. Gardenia likes all types of fertilizer. Now it will depend on you what type of fertilizer you like to apply on gardenias.

You need to prepare a dilute solution for applying water-soluble and liquid fertilizer. In contrast, you don’t need to prepare a solution for applying granular fertilizer but you have to work on the surface soil after sprinkle the granular fertilizer around the base of the gardenias.

Spike type fertilizer is also available in the market today. For applying the spike fertilizer, simply push the spikes into the 1-2 inches of soil. In my opinion, spikes type of fertilizer is the best fertilizer for potted gardenias.

When to Fertilize Gardenias?

The growing season is the perfect time to apply fertilizer to gardenias. Apply fertilizer to your gardenia from spring to mid-autumn by following the label instruction and stop feeding a month before winter comes.

How often to Fertilize Gardenias?

The fertilizing schedule may vary depending on gardenias requirements, types of fertilizer, and soil quality.

Generally, water-soluble fertilizer applies more frequently because it can only feed instantly but slow-release fertilizer can feed continuously so you don’t need to apply it frequently.

Generally, the water-soluble fertilizer applies after 7-14 days and slow-release fertilizer once per month. 

How to Fertilize Gardenias?

There are no hard and fast rules for feeding the gardenia plant. But here I will discuss the best way to apply fertilizer to gardenias. Let’s strat-

Step 1: Pick the Best Fertilizer for Your Gardenias

Healthy food means healthy plants. So you need the best food for your gardenias. Pick any fertilizer from the list of my top fertilizer or follow the buying guide and buy the perfect fertilizer.

Step 2: Choose the Right Time for Fertilizing

Fertilizing in hot sunny days can damage plant health.So.you should fertilize your gardenia in cool and calm weather.

Early morning or evening can be the best time for applying fertilizer to the gardenia because this is the time when the weather remains calm and windless. Never apply fertilizer on outdoor gardenias if there is a little chance of rain recently.

Step 4: Measure and Prepare a Solution

Measure the fertilizer according to the label direction and prepare a dilute solution if the fertilizer is water-soluble. Otherwise, you don’t need to pre-mixed with water. Also, you can ignore this step if you pick spike fertilizer.

Step 3: Apply The Fertilizer On Gardenias

Water-soluble fertilizer: Pour the pre-mixed dilute solution around the base of the gardenia plant. If the fertilizer permissible to spray on foliage, then spray the leaves until they wet completely.

Granular fertilizer: Sprinkle pre-measured fertilizer around the drip line or the edge of the container and apply water thoroughly.

Spike fertilizer: Take the one or more spike according to the size of the plant. Push the spike into 1-2 inches soil near the stems of the plants and water the plant.

How to Make Soil Acidic for Gardenias?

Method 1: Apply White Vinegar

Items Required:

  1. White Vinegar
  2. Watering Can

Steps:

  1. Simply mix 1-2 teaspoons of white vinegar while watering.

Method 1: Sprinkle Coffee Grounds

Items Required:

  1. Coffee Grounds

Steps:

  1. Sprinkle a handful of coffee grounds around the base of the gardenia.
  2. Apply water to the plant.

You can also apply commercial soil acidifiers to make the soil acidic. Here is the best organic soil acidifier for you-

Homemade Fertilizer for Gardenia

Items Required:

  1. Epsom Salt
  2. Eggshells
  3. Coffee Grounds
  4. Banana Peels
  5. White Vinegar
  6. Watering can

Steps:

  1. Cut the banana peels into small pieces and dry it in the sun then grind the dried banana peels.
  2. Also, grind the dried eggshells.
  3. Mix the crushed eggshells, banana peels, and coffee grounds in equal ratio.
  4. Sprinkle the mixture around the base of the gardenias.
  5. Pour water into the can and mix 1 teaspoon of white vinegar and Epsom salt.
  6. Mix properly and apply water to the plant.

Note: Epsom salt, coffee grounds, eggshells, banana peels are the natural sources of magnesium, nitrogen, calcium, potassium respectively. Besides, they also provide some other essential plant nutrients and vinegar can acidify the soil.

Frequently Asked Questions

#Can You Use Epsom Salt on Gardenias?

Chemically, Epsom salt is hydrated magnesium sulfate. It is the natural source of magnesium. It helps the gardenia plants bloom and develops dark green leaves. So, you can feed Epsom salt to your gardenias.

#Are Coffee Grounds Good for Gardenia Plants?

The pH of coffee grounds is 4.5 – 6.0. That means it is highly acidic. So if you apply coffee grounds on gardenias, the soil becomes acidic and you know acidic soil is good for gardenias. Moreover, coffee grounds feed nitrogen to the plant,

#Are Eggshells Good for Gardenias?

Chemically, eggshells are calcium carbonate crystal. So the eggshells can feed calcium to the gardenias and calcium is the essential plant nutrients. So, eggshells are good for gardenia plants but remember excessive calcium can increase the soil pH.

#Are Banana Peels Good for Gardenia Plants?

As a fertilizer banana peels are good for all plants.It contains 42% potassium,and 25% phosphorus.You know; potassium and phosphorus are the primary nutrients of plants that help the gardenias to produce more robust and colorful blooms.

Read more: How to Make Banana peels Fertilizer

#Are Gardenias Acid Loving Plants?

Gardenias are an acid-loving plant. They grow well and produce lots of blooms in acidic soil. The optimum pH range for Gardenias is  5.0-6.0

#How Do I Fix Yellow Leaves on my Gardenia Plant?

Iron and magnesium deficiency are the main cause of yellow leaves (chlorosis) of gardenia plants.

If the base of the leaves turn yellow but tips remain green, then the magnesium deficiency is the cause of chlorosis. In contrast, if the tips become yellow and the base and veins of the leaves remain green, then it may happen for iron deficiency.

Here is the fertilizer for yellow leaves of gardenia-

Feed Epsom salt(our pick: Solimo Epsom Salt) to provide magnesium and feed iron tone(our pick: Espoma IT’5 Iron Tone Bag) or liquid chelated (our pick: Southern Ag Chelated Liquid Iron)to provide iron.

#Is Miracle-Gro Good for Gardenias?

Miracle-Gro is a popular brand for fertilizer.They have been producing lots of products but all the fertilizers are not good for gardenias.You know, gardenias are acid-loving plants.So, the acid-loving fertilizer from Miracle-Gro can be the best for gardenias.

Conclusion

Gardenias are beautiful plants that you can grow in pots or ground. Choose the right soil and fertilizer for your gardenias and enjoy their blooms and fragrant without facing the problems like yellow leaves, and poor flowering set.

And I hope you picked the best fertilizer for gardenias. Now read the label carefully, feed the fertilizer by following the direction, and wait. A sweet smell of gardenia blooms will cover your yard or home very soon.

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