6 Best Fertilizer for Dahlias 2023 [Top Picks & Reviews]

Everyone likes the colorful, long-lasting bigger blooms of Dahlias. But you should know; Dahlia plants need the perfect plant food to produce the desired blooms.

So, If you want beautiful flowers of Dahlias, you need to feed the best fertilizer.

Now the question; what is the best fertilizer for Dahlias?

In short, the organic or inorganic type of fertilizer contains a lower amount of nitrogen and a higher amount of Phosphate. Also, the fertilizer contains some other macro and micronutrients.

For your convenience, Here I reviewed the 7 best fertilizers for Dahlias. You can pick any of the fertilizers from the list for all the varieties of Dahlia plants including swan island dahlias, dinner plate dahlias.

Top 6 Fertilizer for Dahlias-Comparisons

Miracle-Gro Bloom Booster Food15-30-15InorganicGranular
Dr. Earth Bud & Bloom Fertilizer3-9-4Organic Granular
Espoma Flower-Tone Plant Food3-4-5OrganicGranular
Jobe’s Organics 09627 Fertilizer3-5-4Organic Granular
Jobe’s Fertilizer Spikes8-9-12InorganicSpike
J R Peters Jacks Classic Fertilizer10-30-20InorganicGranular

Top 6 Fertilizer for Dahlias-Reviews

1. Miracle-Gro Water Soluble Bloom Booster Flower Food

Miracle-Gro 1001921 Water Soluble Flower Food

If you need the best fast-releasing fertilizer for Dahlias, Miracle-Gro Water Soluble Bloom Booster Flower Food is for you. Miracle-Gro is a well-known brand for plant fertilizer today. So, you should pick this fertilizer without any hesitation.

According to the label of the fertilizer, this water-soluble fertilizer contains 15% Nitrogen,30% phosphate, and 15% potash. And you will be happy to know; the 15-30-15 NPK ratio is perfect for Dahlias to bloom.

The best part of this fertilizer is; the nutrients come in a water-soluble form. That means the nutrients dissolve instantly and feed the plant quickly. So, this fertilizer is perfect for your most hungry Dahlia plants.

Also, this fertilizer has other plant food including 0.02% boron,0.07% copper,0.15% iron,0.04% manganese,0.0005% molybdenum and 0.06% zinc.

Good news; most of the micronutrients of Miracle-Gro come in a chelated form that can prevent the nutrients from the soil reaction and keep the nutrients always available for the plant.Sounds impressive, right?

It is an inorganic fertilizer. But don’t worry, all the nutrients are derived from some non-toxic ingredients such as ammonium phosphate, urea, potassium chloride, boric acid, and so on.

You can feed this fertilizer to your indoor and outdoor Dahlias to get beautiful blooms. To feed indoor Dahlias-

Mix ½ teaspoon into a gallon of water and mix 1 tablespoon into a gallon of water for outdoor plants. Pour the solution on the base of the plant and repeat the process after 1 or 2 weeks.

2. Dr. Earth Organic And Natural Flower Girl Bud & Bloom Booster Fertilizer

Dr. Earth GL61100518430 Fertilizer

Are you looking for the best organic fertilizer for Dahlias? You can pick the Dr. Earth Organic And Natural Flower Girl Bud & Bloom Booster Fertilizer. It is an OMRI-listed organic fertilizer for flowering plants.

According to the NPK number, this natural fertilizer contains 3% water-insoluble nitrogen,9% phosphate, and 4% potash. The water-insoluble nitrogen releases slowly and can feed your Dahlias continuously up to 1 to 2 months.

It may contain some other plant nutrients for your Dahlia plants. But from my research, I didn’t get any specific data. But how do I know, it contains other nutrients? 

Because it is derived from some natural and organic sources such as fishbone meal, bone meal, alfalfa meal, feather meal, kelp meal, etc. All are safe and organic ingredients for the plant that contains most of the plant nutrients including macro and micronutrients.

The best part of this fertilizer is the Trubiotic formula. That means it contains some colony-forming units including beneficial soil bacteria and mycorrhiza. This formula increases soil fertility and makes the plant resistant.

To get the beautiful blooms,

Apply 1-2 cups on the established Dahlia plant and water to start feeding. Repeat the application after 30 or 60 days.

3. Espoma Flower-Tone Natural & Organic Fertilizer for Abundant Blooms

Espoma Organic Flower-tone 3-4-5 Natural & Organic Plant Food

Espoma is a popular brand of organic plant fertilizer that has been producing premium quality fertilizer for almost 90 years. Here is the Espoma Flower Tone Fertilizer that is specially formulated only for flowers such as Bougainvillea, dahlias, and so on.

According to the granular analysis, It has 3% nitrogen, and the good news; it has both water-soluble and insoluble nitrogen.

You know; water-soluble nitrogen feeds the plant instantly and water-insoluble nitrogen acts as a slow-release nutrient. Also, it has 4% phosphate,5% potash,5% calcium,0.5% magnesium, and 1% sulfur.

And the Espoma Flower Tone fertilizer is formulated from some organic and natural sources such as feather meal, poultry manure, bone meal, alfalfa meal, greensand, sulfate of potash, and so on.

As you noticed, all are natural and organic ingredients. So, you can apply this organic fertilizer to your Dahlias to promote flowering.

Like other organic fertilizers, it also has a mixture of soil microbes that is called Bio tone. This Bio-tone formula makes your plant healthy and resistant.

To get the beautiful blooms-

Apply 2 tablespoons to ½ cups of the slow-acting fertilizer for Dahlias every month according to your plant and container size. Work on the soil and apply water to start feeding the Dahlias.

4. Jobe’s Organics 09627 Fertilizer

Jobe's Organics 09627 Fertilizer

Here is another best organic Dahlia fertilizer from Jobe’s. Jobe’s is a popular brand that has been supplying safe and quality organic fertilizer since 1983. This fertilizer is specially formulated for annual and perennial flowering plants such as Geranium, Merigold, Dahlias, etc.

The NPK number of this Jobe’s Organic fertilizer is 3-5-4. That means it has 3% nitrogen,5% phosphate, and 4% potash for your pants to provide the primary plant nutrients.

It also acts as a slow-releasing fertilizer because it has 1.8% water-insoluble nitrogen. And for quick feeding, it also contains 1.2 % water-soluble nitrogen.

As the secondary plant nutrient, it also contains 8% calcium,0.5% magnesium, and 1.6% sulfur.

This is an OMRI-certified organic fertilizer and which means; this fertilizer is free from toxic chemicals. It is mainly extracted from feather meal, bone meal, processed poultry manure, and sulfate of potash.

The unique feature of the fertilizer is Biozome. Let me explain what is Biozome. Biozome is a healthy and natural blend of soil microorganisms that helps to break down the mineral and improve soil quality as well as plant health.

Mix ½ cup on the topsoil of the Dahlia plant and apply water. Repeat the feeding after 4-8 weeks to get better results.

5. Jobe’s Hanging Baskets and Potted Plants Fertilizer Spikes

Jobe's Hanging Baskets and Potted Plants Fertilizer Spikes

Jobe’s strikes again with the best spike fertilizer called Jobe’s Hanging Baskets and Potted Plants Fertilizer Spike. Let’s see what’s inside the fertilizer bag-

As the essential plant nutrients, every spike contains 8% nitrogen,9% phosphate, and 12% potash. And you will be happy to know; the 8-9-12 NPK ratio is perfect for Dahlias and other flowering plants.

I didn’t find any reference for the micronutrient. So, if you pick this fertilizer, you may apply some micronutrients additionally. But you should ignore it if you added a premium garden or potting soil.

Also, this fertilizer contains Nitrosopumilus maritimus as the non-plant food that makes your potting and garden soil fertile.

You know; this is the spike fertilizer and the best part of the spike fertilizer is; it contains both water-insoluble and soluble nitrogen, phosphate, and potash. So, this fertilizer acts as both slow and quick-release fertilizer.

Another benefit of spike fertilizer is; it has a lower chance of wash out with surface running water.

To apply this easy to use fertilizer-

Simply insert 1 spike near the base of the Dahlia plant and apply clean water. Reapply after 8 weeks.

6. J R Peters Jacks Classic Blossom Booster Fertilizer

J R Peters Inc 51024 Jacks Classic No.1.5 10-30-20 Blossom Booster Fertilizer

Last but not the least, I am going to introduce you to the best bloom booster fertilizer from  R Peters Jacks Classic. It is an inorganic water-soluble fertilizer that is perfect for your Dahlias to bloom.

As the primary nutrients, this J R Peters Jacks Classic Blossom Booster Fertilizer contains 10% nitrogen,30% phosphate, and 20% potash. The higher amount of phosphate helps your Dahlias to promote flowering. That’s why it’s called a bloom booster.

As the secondary plant nutrient, it contains 0.5% magnesium,0.02% boron,0.05% copper,0.1% iron,0.05% manganese,0.0009% molybdenum, and 0.05% zinc. As you saw, it has all the required nutrients to complete the life cycle of the plant.

The good news; the micronutrients have an organic coat(chelated) that protects them from soil reactions and keeps them always available for Dahlia plants.

You know; it is an inorganic fertilizer but there are no toxic chemicals. The nutrients are extracted from non-toxic chemicals such as monoammonium phosphate, monopotassium phosphate, potassium nitrate, magnesium sulfate, boric acid, and so on.

Mix 1 tablespoon into a gallon of water for the outdoor plant and mix ½ teaspoon into a gallon of water for the indoor plant. For better results, apply the solution once every 7-14 days.

What To Feed Dahlias?

Healthy Dahlias Flower

The plant needs food to survive. Every plant needs macro and micronutrients to complete its life cycle. But the amount of the nutrients may vary depending on the plant species. Dahlia plants need high phosphate, a lower amount of nitrogen, and potash from early July to early September.

How To Fertilize Dahlias?

Dahlias Fertilizing Process

Just take some fertilizer and sprinkle it around the plant base. Sound simple, right? But you should follow some steps to feed your plant perfectly. Let’s see what are the steps-

For granular fertilizer-

  1. Measure the fertilizer according to the label direction.
  2. Sprinkle the granular fertilizer around the plant base of your dahlia.
  3. Mix the fertilizer into the soil gently.
  4. Apply water to the dahlia to start feeding.

For liquid/water-soluble fertilizer-

  1. Measure the fertilizer and water according to the direction.
  2. Mix the pre-measured fertilizer into the water.
  3. Soak the plant base with the water.

For spike soluble fertilizer-

  1. Take the 1-2 spikes according to the label or plant size.
  2. Simply push the spike near the dahlia plant base.
  3. Apply water.

Frequently Asked Questions

How much sun do dahlias need?

Dalia plants are heliophyte plants that mean they need full sun to bloom. According to the plant researcher, Dahlias need 6-8 hours of full sun in a day to grow and bloom.

When do dahlias bloom?

Generally, Dahlia blooms from midsummer through autumn(late June to early December)

Do dahlias bloom all summer?

Yes. Dahlias keep blooming all summer. 

How long does it take for dahlia bulbs to sprout?

The answer to this question is depending on the variety of the dahlias. But according to my research, the bulbs take 4 to 6 weeks to sprout.

Is Miracle Grow good for dahlias?

You know Miracle-Gro is a well-known brand of fertilizer. They have been producing different types of fertilizer. And all the fertilizers are not perfect for Dahlias. You can try Miracle-Gro water-soluble bloom booster flower fertilizer for your Dahlias.

Is bone meal good for dahlias?

Bone meal is a good source of phosphorus and calcium and you know, phosphorus is good for flowering plants like dahlia. So you can feed 1-2 tablespoons of bone meal to your dahlias.

Are coffee grounds good for dahlias?

Coffee ground is also good for dahlias. Because it can supply nitrogen to the dahlias. But you should remember; excess nitrogen makes the plant bushy without blooms.

Is Epsom salt good for dahlias?

You can feed Epsom salt to your dahlias. It can provide magnesium to your plant. Magnesium is a secondary nutrient for dahlia that needs a very little amount to grow dahlia successfully.

Is cow/chicken manure good for dahlias?

Cow and chicken manure also provide nitrogen to the plant. And I already told you that nitrogen is good for plants but excess nitrogen prevents flowering.

Is fish fertilizer good for dahlias?

Yes. Fish fertilizer is good for dahlias. Fish fertilizer contains most of the required nutrients for dahlias.


This is the time to wrap up. I hope you can pick the best fertilizer for dahlias. Now feed your plant according to the dosages and take good care of dahlias. You will definitely get lots of healthy blooms in the upcoming season.

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