7 Best Fertilizer For Rhubarb 2023 [Reviews & Guide]

Whenever we look at our Rhubarbs, we look at the stem first. We start measuring how long it is, or how red it is, right?

Let me tell you, leave this whole measuring thing to the fertilizers. Provide your Rhubarbs an ideal fertilizer & get the expected result.

But the question is- Which fertilizers are ideal for Rhubarb?

In Short, any fertilizer that supplies a considerable NPK along with other macro & micronutrients, improves soil’s organic nature & ensures both instant & long-term feeding.

Sadly, it’s hard to get an ideal fertilizer because almost no fertilizer covers 100% requirements.

But don’t worry. keeping all this in mind, I have researched a lot & finally came up with the 7 best suitable fertilizers for your Rhubarbs.

I believe your Rhubarbs would love to get any one of these. Let’s check them out-

Top 7 Fertilizer For Rhubarb- Comparisons

Espoma Plant Tone Plant Food5-3-3GranularOrganic
Miracle-Gro All Purpose Plant Food24-8-16GranularInorganic
Jobe’s Organic Plant Food2-5-3GranularOrganic
Dr. Earth Vegetable Fertilizer4-6-3GranularOrganic
Miracle-Gro For Vegetables18-18-21GranularInorganic
Jobe’s Organic Herb Plant Food4-3-3SpikeOrganic
JR Peter Jack’s Classic Fertilizer20-20-20GranularSynthetic

Top 7 Fertilizer For Rhubarb- Reviews

1. Espoma Plant-tone All-Purpose Plant Food

Espoma Organic Plant-Tone 5-3-3 Natural & Organic All Purpose Plant Food

My first recommendation is an All-purpose fertilizer from the Espoma brand. So far, the product is well-received by the gardeners for its efficiency & I might include that it is a high-rated fertilizer in the case of “Value for Money.” So, let’s check out the details-

Nutrient Composition

Espoma All-purpose Plant food stocks an NPK ratio of 5-3-3. That means if you provide 100g of this fertilizer, your Rhubarb plant will get 5g Nitrogen, 3g Phosphorus & 3g Potassium from it.

And it gets better as this fertilizer provides other macronutrients (required in higher quantities) like- Calcium (5%), Magnesium (1%) & Sulfur (1%).

Good news- all these nutrients are from natural & organic sources. Such as feather meal, bone meal, poultry manure, alfalfa meal, green sand, sulfate of potash, sulfate of potash magnesia, etc.

And interestingly, these sources also supply micronutrients (required in smaller quantities) like iron, manganese, copper, zinc, molybdenum, boron & chlorine

Nutrient Analysis

This fertilizer contains 2% water-soluble & 3% water-insoluble Nitrogen. That means your Rhubarb stalks will get both an immediate & long-lasting supply of nitrogen for healthy growth.

You know, Rhubarbs need everything in higher quantities, especially during the first year. That’s why equal quantities of P & K would come in handy.

However, Ca, Mg & S increase the organic content of the soil & guess what? Rhubarbs love soils rich in organic materials.

Finally, the micronutrients aid in root development & bud forming which assures continuous stalks for a long period.

Special Features

This re-sealable bag carries brownish dust that is suitable for all your garden trees, shrubs, vegetables & flowers. Moreover, it comes with an exclusive BioTone formula- a composition of beneficial colony-forming units like bacteria & mycorrhizae to keep your soil fertile.

Additionally, the fertilizer contains 1% Humic acid to help your Rhubarb in nutrient uptaking, root growth, drought toleration & so on.

Applying Procedures

For potted Rubarbs, mix 3 teaspoons of the fertilizer with the topsoils of a 9-inch diameter pot. And then, water thoroughly & re-apply after one month.

2. Miracle-Gro Water Soluble All Purpose Plant Food

Miracle-Gro Water Soluble All Purpose Instant Fertilizer for Plants

I have gone through several scientific studies to understand Rhubarb’s fertilizer requirements. All the studies concluded that Rhubarb is a heavy feeder, primarily as seedlings. And they require high N, P, K, Ca & Mg to gain that fleshy stalk.

However, Miracle-Gro All-purpose plant food is one of the best fertilizers for Rhubarb seedlings. Why? Let’s see-

Nutrient Composition

It is an inorganic fertilizer as the nutrient sources are ammonium sulfate, potassium chloride, potassium phosphate, iron EDTA, urea, etc.

However, Miracle-Gro displays quite impressive nutrient composition. It contains 24% nitrogen, 8% phosphorus & 16% potassium along with 0.02% boron, 0.07% copper, 0.15% iron, 0.05% manganese, 0.0005% molybdenum & 0.06% zinc.

Nutrient Analysis

During the establishment year, Rhubarb seedlings need proper nutrients to set & grow. Especially, Nitrogen & potassium are highly required for vigorous growth. And there comes the water-soluble plant food with high nutrient composition.

You know, water-soluble fertilizers are instant feeders & ensure the highest uptake by the plants instantly. So, if fertilizing frequently is not an issue for you, then you should go for it. Definitely, it is a great deal for seedlings.

Special Features

This plant food ensures the bigger growth of Rhubarb stalks. Along with that, you can use it on other shrubs, vegetables, flowers, and trees in your garden too.

Interestingly, the fertilizer carries iron & manganese which are combined with an organic chemical called chelate. And chelate keeps these nutrients in an available form to uptake.

Applying Procedures

For potted Rhubarbs, mix half teaspoon of fertilizer with 4 liters of water & soak the soil. It will remain effective for 2 weeks.

3. Jobe’s Organics Vegetable & Tomato Granular Plant Food

Jobe’s Organics 9026 Fertilizer

Good fertilizer for Rhubarb,” “Best type of fertilizer for Rhubarb“- Rhubarb growers often come up with such comments about this fertilizer.

Statistics say home gardeners rely on Jobe’s Organics products for their unique blends & features. Let’s see what this fertilizer has-

Nutrient Composition

This OMRI-approved fertilizer derives all of its nutrients from 3 natural sources & they are- Bonemeal, processed poultry manure & sulfate of potash.

However, the NPK ratio is 2-5-3. And other labeled macronutrients are- Ca (7%), Mg (0.5%) & S (1.4%). But, the good thing is, the sources also supply some micronutrients, such as Mn, Cu, Zn, Cl, B, Fe, and Mo.

Nutrient Analysis

You have noticed that the fertilizer is rich in phosphorus (5%) & calcium (7%). The reasons behind this are- phosphorus stimulates strong root growth & stem development of Rhubarbs. On the other hand, calcium protects your Rhubarbs from harmful toxins & slows down their aging process.

Besides P & Ca, the fertilizer contains 0.8% water-soluble & 1.2% water-insoluble nitrogen to ensure both instant & long-term feeding. Moreover, bone meal- one of the nutrient sources, also ensures a stronger root system. Impressive, right?

Special Features

The fertilizer is a unique formulation for organic gardening. Additionally, it comprises Jobe’s Special Biozome- A blend of beneficial colony-forming bacteria, endo mycorrhizae & archaea. This blend keeps your soil fertile & rich in organic matter.

Applying Procedures

For established potted Rhubarbs, apply one & a half cups of the granular fertilizer per foot of plant spread. After that, water thoroughly & you may have to re-apply after 4-6 weeks.

4. Dr. Earth Organic Tomato, Vegetable & Herb Fertilizer

Dr. Earth Organic 5 Tomato, Vegetable & Herb Fertilizer Poly Bag

Are you looking for the ideal organic fertilizer for your Rhubarb, Asparagus & such vegetables? Well, you can depend on Dr. Earth. Why? Let’s see-

Nutrient Composition

It is an OMRI-listed product & all of its nutrients are from organic origins like fish bone meal, bone meal, feather meal, alfalfa meal, potassium sulfate, fish meal, kelp meal, rock phosphate & kelp flour.

It contains 4% N, 6% P, 3% K & 7.5% Ca. The good news is its natural sources also add other essential nutrients like magnesium, sodium, iron, manganese, copper, zinc, chlorine, boron & molybdenum to the soil.

Nutrient Analysis

This fertilizer offers all of its nitrogen for slow release. Definitely, it is perfect for established Rhubarbs but okay with seedlings too.

All the other nutrients are water-soluble. So, it will take care of both instant & persistent feeding of your Rhubarbs.

Special Features

The best feature of this product is it includes TruBiotic, a broad-spectrum colony-forming soil inoculant. It is made up of beneficial microbes & mycorrhizae to nourish your soil.

You already know that Rhubarbs flourish in highly organic-rich soil. Plus, organic material ensures well-drainage. To check both issues, 6% humic acid is present in the fertilizer.

Applying Procedures

It is a granular fertilizer. So, sprinkle half a cup of fertilizer over the topsoil of a 12-inch diameter pot. And before thoroughly watering, mix the soil slightly with a hand rake.

5. Miracle-Gro Water-Soluble Plant Food For Vegetables & Herbs

Miracle-Gro Water Soluble 2 lb Plant Food for Vegetables & Herbs

Miracle-Gro hits again! It is one of the best water-soluble fertilizers for Rhubarbs. Care to know the reasons? Well, let’s start with its enriched nutrient composition-

Nutrient Composition

The fertilizer is high in N, P & K as the NPK ratio is 18-18-21. Along with this, it encompasses other essential macro & micronutrients, such as 0.50% Mg, 0.02% B, 0.05% Cu, 0.10% Fe, 0.05% Mn, 0.0005% Mo & 0.05% Zn.

And for your concern, these nutrients are derived from safe & eco-friendly inorganic sources.

Nutrient Analysis

You know, seedling or established, Rhubarbs demand high N, P & K for that reddish stalk. And this plant food takes care of that.

Generally, plants can uptake Nitrogen in the form of Ammonium (NH4+) & Nitrate (NO3-). This fertilizer ensures both of these forms for sufficient Nitrogen Uptake.

Moreover, it is a water-soluble fertilizer which feeds your Rhubarbs instantly for active growth. And last but not the least, Fe & Mn are present in the chelated form to ensure their bioavailability & to avoid undesired & harmful reactions for Rhubarbs.

Special Features

Miracle-Gro Water-soluble fertilizer is a “Soil + Plant” food. It takes care of both the above & below ground parts of your Rhubarb. And also, the company promotes this product for high quantity harvest of vegetables.

Applying Procedures

Mix one & half tablespoons of the fertilizer with 2 liters of water & soak the base soil of your Rhubarb plant. And you can relax for another 7-14 days.

6. Jobe’s Organics Herb Plant Food Spikes

Jobe's Organics Herb Plant Food Spikes

 I have brought forward another Jobe’s product & this time is a spike fertilizer. So, if you were asking about what is the best spike fertilizer for Rhubarb, here’s your answer-

Nutrient Composition

It is an organic fertilizer as all the nutrients are from natural & organic origins like bone meal, feather meal & sulfate of potash.

However, each fertilizer spike supplies 4% N, 3% P & 3% K. Though the company has not mentioned the presence of any other nutrients, my research says the sources also provide calcium, iron, magnesium, sulfur, and zinc.

Nutrient Analysis

As you see, spikes supply a similar amount of P & K to feed your Rhubarbs instantly to boost up the growth. But among its total N content, 2.4% N is water-insoluble.

Water-insoluble N takes time to get uptaken by Rhubarbs as it dissolves in water slowly. Thus a steady N supply is assured.

You know, N is very essential as it involves photosynthesis- a natural food-making mechanism of plants. So, Rhubarbs are always hungry for Nitrogen & the spikes promise you to take care of that.

Special Features

The spike formation itself is a specialty. As the spikes are premeasured, you are literally relieved from any type of measuring or guessing.

And additionally, Jobe’s Organics hasn’t forgotten to add their special Biozome formula in it too. You know, this special blend of beneficial microbes keeps your soil alive and improves the soil-plant relationship. So, what else do you need?

Applying Procedures

For a 5-6 inch diameter Rhubarb container, press 8 spikes around the container edge & then water thoroughly. And if you are thinking about how deep should you press, roughly, 1-2 inches is fine.

7. JR Peters Jack’s Classic All-Purpose Fertilizer

J R Peters 52024 Jacks Classic No.1.5 20-20-20 All Purpose Fertilizer

As I said, many scientists & experienced gardeners found that all-purpose fertilizers are quite effective for Rhubarbs. And in the case of all-purpose fertilizer, jack’s classic is renowned for its well-researched high nutrient composition.

Nutrient Composition

Though the nutrients are derived from inorganic sources like urea, monopotassium phosphate, potassium nitrate, boric acid, iron EDTA & so on, the NPK ratio is like hell yeah! It is 20-20-20.

But that’s not all. The fertilizer provides 6 more micronutrients to lift up your Rhubarb’s growth. And those are- 0.02% boron, 0.05% copper, 0.10% iron, 0.05% manganese, 0.0009% molybdenum & 0.05% zinc.

Nutrient Analysis

Like all other balanced fertilizers, it supplies an equal amount of nitrogen, phosphorus & potassium. And that puts you in a relaxing position as nothing is going up or nothing is going down.

Moreover, its water-soluble nature ensures instant feeding for your Rhubarb. So, do you think a starving Rhubarb could ask for anything else? I don’t think so.

Special Features

Along with Rhubarbs, this fertilizer will treat all the flowers, turfs, vegetables & trees in your garden. & that’s why it is an all-purpose fertilizer.

Moreover, the feeding process of this fertilizer is pretty impressive. Interestingly, it feeds through both roots & leaves. So, whenever you apply it, your Rhubarb plants will have a feast.

Additionally, the fertilizer contains chelated copper, iron, manganese & zinc to ensure proper availability & circumvent undesired reactions.

Applying Features

Mix 1/4 teaspoon of this fertilizer per gallon of water & spray or soak the soil. That would be all.

What Do You Feed Rhubarb?

Feeding Rhubarb

In the case of feeding Rhubarb, you must keep two things in your mind-

  1. It’s good for Rhubarbs if N, P, K, Ca, Mg & B are continuously available in the soil (along with other macro & micronutrients). And it is better if these nutrients are available in higher quantities. And
  2. Rhubarbs grow their fullest in organic-rich soil.

So, keeping these in mind, you should provide fertilizer that is suitable for your Rhubarbs. Look for vegetable & herb fertilizers, all-purpose fertilizers, or balanced fertilizers that match best with your Rhubarb’s requirements. And to enrich organic content, you can add compost, manure, or green manure to the soil.

How to Grow Thick Rhubarb Stalks?

Thick and Healthy Rhubarb Stalks

Rhubarb pies or muffins, whatever you like, the first requirement is juicy thick Rhubarb stalks. And to get thick red stalks here is some caring tips for you-

  • Always keep the soil weed-free to reduce competition for nutrients.
  • Normally, Rhubarbs uptake water from 12-18 inches deep. So, make sure moisture is available there.
  • Maintain the soil pH between 6.0-6.8. Add lime with the soil if necessary.
  • For high stalk production, use fertilizers rich in N & K.
  • Always take precautions to protect your Rhubarbs from the attack of insects, fungus & other pathogens.
  • Cut down all the flower-bearing stalks as soon as they appear.
  • It is better if the first season goes unharvested.

Frequently Asked Questions

Is Miracle-Gro Good For Rhubarb?

Both Miracle-Gro “all-purpose” & “vegetable & herbs” plant foods are perfect for Rhubarbs. These fertilizers supply all the essential nutrients instantly & improve the soil quality.

Does Rhubarb Like Coffee Grounds?

Coffee grounds add nitrogen, phosphorus, potassium & Magnesium to the soil. And Rhubarbs need all of these. So, Rhubarb does like coffee grounds. But make sure, you are not over-applying.

Are Banana Skins Good For Rhubarb?

Banana skins or peels supply plenty of nutrients to the soil like phosphorus, iron, calcium, magnesium, sodium, zinc, copper & potassium. And from long ago, banana peels were used for vegetables like Rhubarb.

Is Bone Meal Good For Rhubarb?

Several fertilizers use bonemeal to get phosphorus & some other minerals. Bone meals strengthen the root establishment of Rhubarb.

Is Tomorite Good For Rhubarb?

Tomorite is mainly used for more & bigger fruit. But it contains seaweed extract which stimulates stem growth. So, I think it is good in exact doses.

Is Seaweed Good For Rhubarb?

Yes, seaweed supplies several essential nutrients for Rhubarb & its high potassium content encourages stem growth & color.

Is Chicken/Sheep Manure Good For Rhubarb?

Both chicken & sheep manure release nutrients slowly & ensure everlasting feeding for Rhubarb. So yes. You can go for it.

Is Blood Meal Manure Good For Rhubarb?

Though blood meal supplies several nutrients & trace elements, it contains a high amount of Nitrogen. So it is good, as long as Rhubarb needs Nitrogen. But be careful about Over-applying.


Rhubarb is a perennial vegetable & once established, you can harvest the reddish stalks for up to 5 years. And that’s why a good fertilizer is necessary to keep it growing vigorously.

In this article, I have reviewed the 7 best Fertilizers for your Rhubarb plant. And while reviewing, I kept in mind that, the product must have to be suitable for Rhubarbs, easy to use & must value your money.

I hope this review helps you pick the right one. And lastly, don’t forget to follow the packet label while applying.

Happy Gardening.

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