7 Best Fertilizers for Gardenia

best fertilizer for gardenia

Gardenia is an aesthetic flowering plant that belongs to the coffee family. It has its origins in the tropical and subtropical regions of Asia, Africa, Madagascar, and other areas. This plant is also symbolic and has come to represent a range of emotions over the years.

Some people consider it to symbolize purity and gentleness. In any case, keeping your gardenia plant healthy and nurtured will be a priority for you. Hence, we have reviewed some of the best fertilizers for gardenia options for you.

Read ahead to understand more about the right fertilizers for gardenias and how you can use them. We have also explored many questions about caring for gardenias for you.

How to Take Care of Gardenia and Grow Gardenia Plants?

If you are reading this, you may have decided to grow some gardenia plants in your garden or backyard. These plants are a delight to care for and nurture. Gardenia has an intoxicating fragrance and looks very pleasing to the eyes.

They generally come with white flowers and have green leaves and foliage with a leather-like look. They are not an easy shrub to grow. However, the process can be an exciting and fun project to take up.

Here is how you can care for your gardenia plants well. The lovely color and fragrance that it leaves in your garden are well worth the effort.

Light Conditions for Gardenia

In general, gardenia plants prefer full sunlight. However, it is best to select a spot that allows for full sun and some light shade to go with it. It is because the summer months can be very harsh and scorch the leaves of the plant. A little shade can keep the plants healthier.

Too much sunlight in the summer may also make the leaves fall off the plant. If the climate is hot, exposure to the morning sun can be best. In the afternoon, light shade can prove more beneficial. If the area is cool, go ahead and expose your gardenia plant to full sunlight.

Make sure to cover their roots with organic mulch in this case. If you are growing your gardenia plants in containers, expose them to filtered shade in a brightly lit area. Keep them away from direct sun for the best growth.

If you are keeping them indoors, leave them next to a sunny window opening. The plants will get about 6 to 8 hours of sunlight here. It will keep them blooming and healthy.

Moisture Conditions for Gardenia

Gardenias do well in soil that is moist and well-drained. It is a good idea to see that there is consistent moisture. Just don’t let the soil around the plant get too soggy. An inch of rain or watering per week should keep them in good shape.

Do note that the soil should not dry out. The plant will not thrive in this environment. On the other hand, over-watering them can lead to buds not opening. It can even lead to falling flowers.

To retain moisture, apply a layer of mulch that comes to about 2 to 4 inches. It will maintain a constant soil temperature. In addition to this, it also keeps up the moisture levels. To get rid of excess fertilizer, simply add some distilled water to the plant once every month.

Soil Conditions for Growing Gardenia

These plants prefer acidic soil that has a pH range of between 5.0 and 6.0. You can test your soil for the same and then treat it to make up for any deficiencies. It is best not to plant the gardenia near a foundation or concrete wall.

It can make the pH too high and can stunt the growth of the plant.

Nutrients that Gardenia Requires

Gardenia loves its nutrients and keeping the soil rich with the same can be extremely beneficial. You can ensure this by adding a good amount of organic matter to your soil. Add some manure or even peat moss and watch your plants bloom.

You can also add some coffee grounds, wood ashes, tea bags, and Epsom salts to feed your gardenias. These are rich in potassium, nitrogen, and magnesium which will keep your gardenias healthy and nourished.

You may also want to pay attention to the N-P-K ratio for gardenia when you get a fertilizer. The N-P-K ratio refers to the amount of Nitrogen, Phosphorous, and Potassium in the fertilizer.

Look for a ratio of 3:1:3 or 3:1:2 for the best results. However, this will differ based on the condition of the soil.

Temperature for Growing Gardenia

There are optimal day and night temperatures are optimal for your gardenia plant and they put on their best performance during this time. The temperature between 65 degrees to 70 degrees Fahrenheit is optimal during the day.

At night, temperatures between 60 degrees to 65 degrees Fahrenheit are favored by the plant. These temperatures are necessary for the formation of flower buds. In general, your gardenia plant will prefer warmer days and cooler nights.

Humidity for Gardenia

These plants require high humidity to bloom. For the extra moisture that they need, you can simply mist them daily with some water. If you are using a potted plant, simply set it on a tray of moist pebbles. You can also take the extra step and use a humidifier.

The extra humidity can also keep away any spider mites. These thrive when the atmosphere is dry.

How Will I Know that My Gardenias Require Fertilizers?

Regularly adding fertilizer to your gardenia plants can keep them healthy in the long run. However, it is not too late yet if you haven’t started. Here are a few signs that indicate that your gardenia plants can use some fertilizer.

Stunted New Growth

Have you noticed that your gardenia plants have been healthy for a long time now? However, you may now notice that the new growth is stunted and slow. The buds may be smaller as well.

This is often a sign that the plant lacks the necessary nitrogen to keep it growing well. In this case, a fertilizer can get the plant back on track.

Yellow leaves

This is another sure sign that your gardenia plants could use some extra care and fertilizer. This can again be traced to the nitrogen in the soil. The leaves of gardenia are directly dependent on the available nitrogen.

Healthy leaves can make all the difference as it is these that enable most of the photosynthesis in the plant. Add the necessary fertilizer and watch your gardenia plant bloom in all its green glory again.

No Growing Buds or Flowers

This can be a sad sight to see on a gardenia plant. This is a direct indication that the nutrients in your plant are scarce and they could do with some fertilizer. At this point, the gardenia slips into survival mode and diverts its attention to survive.

Root development and plant survival take all of its resources. Under these circumstances, the buds and flowers are ignored, and hence absent. To solve this problem, simply fertilize your gardenias and you will see the flowers blooming yet again.

Regular and consistent fertilization can keep all of these issues at bay. As they say, prevention is better than cure and it stands true for your gardenia plants as well.

When Should You Fertilize Gardenias?

The best time to fertilize gardenia is during their growth cycle. During this time, you can support their growth cycle and keep their development and flowering going. Pay special attention to the plants during their reproductive cycles.

They tend to require the most nutrients during this time. It is because they are using their energy not only to nourish themselves but also the baby plants that they are creating. You can fuel the growth of your gardenia by adding the essential nutrients to the soil.

You can do this by using fertilizer. Here are a few things you should know about the best time to fertilize your gardenia plants.

Prime Time for Fertilization

This is usually between April and November when the plants can do with the most nutrients. Most professional and home gardeners use this time to fertilize their plants and get them ready for the coming months.

The time for fertilizing your garden will also depend on the gardening zone you are in. Determine this and pick the best month for you.

Time the Fertilizer’s Use

Once you know the right season to fertilize your gardenia, you should also pick the right frequency. You don’t want to over-fertilize your gardenia. To avoid this, apply your fertilizer once every two to four weeks.

Some fertilizers will require you to use them once every week along with watering. Here is the thumb rule for your gardenia. Choose a longer interval between fertilization rather than a shorter one. You don’t want a higher frequency to leave your gardenia’s roots burnt.

Time to Avoid Fertilization

You should avoid fertilizing your gardenia plants during the fall. Do not fertilize them during the dormant winter months either.

How Should You Fertilize Your Gardenia?

Gardenia fertilizers come in various forms and types. Hence, when you use a fertilizer for your gardenia, read the package instructions carefully. Use only the amount specified in the optimum ratio. It will keep your plants from burning from the excess application of fertilizer.

The fertilizer you opt for may come in powder form. It may also come in the form of pellets, or liquids. They will have to be mixed with water or added directly to the soil, as per the instructions. Do not sprinkle any fertilizer on the leaves of the plant.

It can disfigure the leaves. If you are new to gardening, this is a common mistake that you should avoid. Take the recommended amount and add it to the soil where it belongs. You can do this with pellets as well.

If your fertilizer needs water, mix it in and add it only to the soil. With this, your plants will absorb the nutrients where it matters.

Using Homemade Gardenia Fertilizers

If you are a gardener who wants to prepare your fertilizer, you have options for the same. Many common ingredients can add much-needed nutrition to your soil. The most popular are old coffee grounds.

They are a great source of much-needed nitrogen for your plant. All you have to do is spread some around the base of your plant. The acid in the coffee grounds will also reduce the pH level of the soil to make it more acidic.

It makes these acid-loving gardenias enjoy their soil. You can also use old manure and tea to make some good compost for your gardenia. When feeding time for your gardenia begins, go ahead and add this to the soil.

Best Fertilizers for Gardenia-Reviews

Here are our top fertilizers for gardenia reviewed for you.

1. Espoma HT18 Holly Tone

N-P-K Ratio: 4-3-4

This is an excellent option for acid-loving plants. Gardenias are plants that love acid and that will benefit substantially from this fertilizer. You can also go ahead and use it on any azaleas, rhododendrons, hydrangeas, ad blueberries you may be growing.

The fertilizer is also great for any strawberries, evergreens, and other acid-loving plants you may have in your garden. The fertilizer’s quality speaks for itself and it is utilized by professionals.

Hence, you can bring this tried and tested fertilizer home to your gardenias. The best part is that this fertilizer has also been approved for organic gardening. For this purpose, it comes equipped with proprietary Bio-Tone beneficial microbes.

You won’t need any assembly to begin using this product. Once you open the bag this fertilizer can have a shelf life of 3 to 5 years. If you want to make it last long, seal it well and store it in a cool and dry place.

Further, the fertilizer will certainly not harm your plants but will only nurture them. You won’t have to work it into the soil either. Just spread it around the gardenia roots and you should be good to go.

Once you begin using this fertilizer, you will notice that all your acid-loving plants will look healthier and fuller. They will also bloom better. This will keep any poor output, growth, and pale leaves out of the picture for your gardenia.


  • Does not require assembly
  • Nurtures acid-loving plants
  • Organic option
  • Fast-acting fertilizer


  • Has to be used sparingly

2. Jobe’s Fertilizer Spikes

N-P-K Ratio: 9-8-7

This fertilizer is specially formulated as pre-measured spikes that are nourishing at the roots. It is a time-release fertilizer that is perfect for your gardenias that are acid-loving. You can go ahead and use it even on other acid-loving plants like hydrangeas.

You won’t have to worry about complex ways in which to get this fertilizer working. These spikes are instead very easy to use. You will notice that there will be no wasteful run-off and no mess as it is used.

Further, these spikes are not hazardous or smelly either. Hence, as the gardenias bloom and flourish, you will stay a happy gardener. The fertilizer spikes provide a continuous boost of nutrition to your acid-loving gardenias from below the surface.

This is where the active roots are present to maximize the reach of nutrition to the plants. You can use Jobe’s spikes to feed your gardenias for the full season’s length.

In addition to this, your azaleas, rhododendrons, hydrangeas, and camellias will be nourished. You can go ahead and apply this fertilizer during the late spring period or even early summer for the best results.

This is just after the plants have shed their blooms. The product also comes in a waterproof pouch that can be sealed again. Hence, your job in using and storing the fertilizer is made that much easier.


  • Easy to use
  • Slow-release fertilizer
  • Easy to store
  • Feeds gardenia below the ground


  • Spikes may break

3. Perfect Plants Gardenia Liquid Fertilizer

N-P-K Ratio: 9-3-6

This is one of the best fertilizer options as it has been specially formulated for gardenia. It allows for nourished gardenia that will show some vibrant growth and blooming. The blooms will be more consistent as well.

This fertilizer will lead to better colors in the foliage and deeper flower colors as well. You will also notice that your plants will be healthier and filled with some great essential nutrients. It will enable the flowering plant to grow larger and sturdier.

The fertilizer is formulated by keeping flowering bushes in mind. Hence, it works perfectly well for your acid-loving gardenia. The N-P-K ratio and application instructions serve both potted plants and those growing freely in the landscape well.

The mix is a concentrated one. Hence, you only have to add a measured amount to water before you begin watering your garden. Further, it has a resealable bottle as well to make storage that much easier. It ensures that the fertilizer is effective for months to come.

You may wonder why should opt for liquid fertilizer. This fertilizer will allow your gardenia to access the nutrients much faster due to its liquid form. It also ensures uniform nutrient consistency for the plants. Finally, you can expect a good starter and in-season application.


  • Packed with nutrients
  • Easy to apply
  • Bottle offers good storage
  • Ensures nutrient consistency


  • May burn some plants

4. Flower Fuel Bloom Booster

N-P-K Ratio: 1-34-32

Ensuring the best blooms for your flowering plants cannot get easier. This bloom booster fertilizer is here to ensure just that. It will see to it that your gardenia bloom heavier and get healthier with each application. It is a super-premium fertilizer with the best nutrients.

It has organics, vitamins, and amino acids to make it an effective fertilizer for your gardenia. It has more resin and essential oil content so that your gardenia plants are larger, denser, and achieve a much better harvest.

 Each jar of this fertilizer has more than 40 proprietary ingredients in it. These include powerful vitamins, hormones, and each micro and trace elements that will leave your harvests healthier.

Using this fertilizer is just as easy as well. It is a 100% hydroponic-grade fertilizer that is soluble. You can use it with any base nutrient to make the best of its abilities for your gardenia. Add it to an aeroponic or hydroponic system if you like.

For gardenia, soil or coco also work with this bloom booster. With each package, you will be able to treat 200 gallons of water. Hence, opting for this fertilizer means that you will be opting for full harvests each season.

Professional gardeners and amateurs use this product in their gardening ventures. Hence, it is a trusted fertilizer and a great accompaniment to all your gardening tools.


  • Good quality fertilizer
  • Leads to bigger harvests
  • Gardenia blooms better
  • Will last for a long time to come


  • May be too strong for a few plants

5. Miracle-Gro 3002210 Plant Food

N-P-K Ratio: 10-18-9

This rose and bloom variation of the fertilizer is excellent if you prefer to grow your gardenias organically. It is because the fertilizer is made of natural ingredients that will feed the microbes in the soil. These microbes go ahead and break down the natural ingredients.

The ingredients present in the soil are converted by the microbes into nutrients that strengthen the gardenia and promote their growth. It begins by supporting the root development and strength of the plant.

This increases water efficiency for increased nutrient delivery and better blooms. You can expect some spectacular color in your garden. Compare any of your unfed plants with the gardenia you have treated with this fertilizer.

You will see that the fed plants are blooming with vitality. You can use this for your new and fresh blossoms. It can also be used on older flowering plants. It will feed your plants for up to 3 months. Hence, you can take the guesswork out of feeding.

Expect a beautiful garden all season long with this fertilizer at your beck and call. Do note that you should use only about 1/2 a cup for every 10 square feet. Over-application can have negative effects on your plant.

You can lightly mix it into a soil that is 1 to 3 inches high for the best results. It has been formulated with kelp, bone meal, earthworm castings, and feather meal to make an organic formula.


  • Spectacular blooms
  • Lasts for 3 months
  • Contains vital micronutrients
  • Great for new and old plants


  • Not meant for heavy-handed use

6. Dr. Earth 703P Organic 4 Acid Fertilizer

N-P-K Ratio: 3-4-3

This fertilizer is recommended if you have children and pets running around in your garden each day. Your pets will tend to sniff around and you want to keep them as safe as possible. Use this fertilizer just as directed and you will have a healthy garden, family, and pets.

It is largely because the fertilizer is free from any synthetic ingredients. Simply use as directed on the package and you will be good to go. Once you apply it, the fertilizer will provide continuous feed for several months to come.

You will find champion strains of some extremely beneficial microbes, in addition to pro-biotic ingredients. It also comes with endo and ectomycorrhizae. It also leaves the soil more acidic which is perfectly beneficial for your acid-loving gardenia.

You will get some superior booms and buds in your garden when you use this. All of this is made possible with a completely organic formula and 100 percent natural. You can expect great results because the right nutrients are released promptly.

Your plants will also be left drought tolerant and performing very well when this fertilizer is added. They will also have enhanced nutrient availability at each stage of their growth It is because of the eight strains of the endo and ectomycorrhizae mentioned above.

You can use it as directed for optimum nutrient delivery to your gardenia. It is now up to the microorganisms in the soil to thoroughly break down the nutrients and let your plants bloom. The fertilizer has been handcrafted from feed-grade ingredients for the best results.


  • Good quality ingredients
  • Microbe-enabled growth
  • Balanced nutrition
  • Child and pet-safe fertilizer


  • May leave an unpleasant smell

7. Miracle-Gro Water Soluble Plant Food

N-P-K Ratio:  30-30-10

This fertilizer is a great option for acid-loving plants like Gardenia. If you like your plants with lush foliage and spectacular blooms, this is the plant food to opt for. In addition to gardenia, you can also go ahead and use it for azalea, rhododendron, and camellia.

All of these are acid-loving plants that this fertilizer will treat just right. Your flowering plants will be fed instantly by this soluble fertilizer. However, do note that you will have to feed your plants every 1 to 2 weeks. Your orchids, hollies, and hibiscus will go ahead and thrive.

You can use the Miracle-Gro garden feeder to get the best of this fertilizer. If you have a watering can of your own, you can go ahead and use it as well. Customize it as you like to feed your gardenia and see your garden bloom.

To use it, fill your feeder jar with the plant food. Attach the hose to your feeder jar and set the desired sprayer pattern. Turn the spray head and squeeze the trigger to spray the feeder on the plants. For a watering can, you can mix half a teaspoon per gallon of water.

The best part is that the nutrients reach your plant as you water it each time. You can even use it for your flowering plants that are acid-loving. It ironizes and acidifies for the best blooms.

You can also use it with drip irrigation and fertilizer method. You will see that your gardenia will grow larger, stronger, and bloom much better as well. It is used by professionals and home-growers alike. You can also use it in your large-scale projects.


  • Won’t burn foliage
  • Easy to use
  • Has the right nutrients for gardenia plants
  • Gives rich color


  • Requires regular usage and maintenance

Frequently Asked Questions (FAQs)

You now know the fertilizers that can keep your gardenia plants thriving. Here are answers to a few other questions you may have.

1. Why are My Gardenia Plants Not Blooming?

An important reason for this is the pruning of the plant. If pruning took place too late during the season, the leaves turn yellow. Another reason your gardenia refuses to bloom may be because of the soil pH which may be faulty. Gardenias prefer acidic soil and the absence of this can affect blooming.

2. Why Are the Leaves on My Gardenia Turning Yellow?

Low magnesium levels in the soil could have caused the yellowing leaves. Fix this by adding fertilizer high in magnesium to the soil. It may also be caused by soil that is low on iron or manganese and even if the soil has not been drained well.

3. Do Gardenias Prefer Sun or Shade?

In general, gardenia plants prefer bright sunlight. However, during the summers, light shade can be very beneficial to these plants. It is because the sun tends to be harsh and can adversely affect the leaves and foliage of these plants.

4. How to Care for Potted Gardenia?

If you grow your gardenia in pots, keep them in the filtered shade where the direct sun does not reach them. Ensure that there is enough moisture to keep the soil damp but also well-drained. Regular fertilization will keep your potted gardenias healthy.


By now, you know that gardenias can be difficult plants to care for. Growing them is no less than a delightful summer project that will yield some beautiful flowers and good fragrance as well. However, once you learn how to care for these plants, it can become second nature.

Among all the other maintenance routines you use, don’t forget the fertilizer. A good fertilizer can leave enough nitrogen in the soil to serve these acid-loving plants well. Be careful to apply just the amount specified on the package.

Any more and you may end up burning your plants’ roots. All of the effort you put in will pay off when the blooming gardenias will light up your garden.