The 9 Best Fertilizers for Cucumbers in 2023: Better Harvest

Pick the right fertilizer to grow healthy cucumbers from our top nine choices of the best cucumber fertilizers. We’ll also discuss the ideal time and process to fertilize cucumbers.

Sean Stratton | Updated March 6, 2023

A good fertilizer can play a significant role in achieving an abundant cucumber harvest. These are the ones we trust to get results every year.

9 Best Fertilizers for Cucumbers

hanging cucumbers with flowers

Keep in mind you will find some fertilizers labeled as cucumber fertilizers and others labeled as tomato fertilizers or all-purpose fertilizers for vegetables.

No worries, these fertilizers can also be used for your cucumbers. You must check the product’s label to ensure it includes cucumbers.

1. Jobe’s Fertilizer Spikes Vegetable

Jobe’s Fertilizer Spikes is the best fertilizer for growing cucumbers. It’s an organic fertilizer formulated for larger harvests with no synthetic chemicals.

It will help to grow the plant naturally and provides a nutritious environment to get a faster result. Jobe’s Biozome helps to improve soil conditions and protects your plants from harmful diseases or insects. It resists drought during the growing season.

It will be easy to apply and save time and effort without unnecessary waste. It distributes nourishment at the roots of your plants properly so that your plants will grow well.

Generally, it’s a pre-measured fertilizer. So you don’t need to face any problems with the fertilizer ratio.

Use the Jobe’s fertilizer spikes early in the season or after the flower appears on the first time to get the best result. You are going to enjoy a mess-free and faster fertilizing experience. Good luck with it!

Also Read: Harvesting Time of Onions

2. Espoma Garden-Tone 3-4-4 Plant Food

For balanced food for your cucumbers, you should check out the Espoma GT4 3-4-4 plant food. This organic formula contains an ideal blend of organic ingredients to nourish your cucumbers and promote better growth. Espoma assures that this Garden-Tone plant food doesn’t contain fillers, sludges, or toxic ingredients. So, you can use it without being concerned about safety.

It comes with Espoma’s exclusive Bio-tone Microbes formula. So, this slow-release formula will provide food to your cucumbers for a long time and it will save you from applying the fertilizer quite often.

You can not only feed your cucumbers with this excellent plant food but it is suitable for a wide range of other vegetables as well. Plus, you can feed both cool and warm-season vegetables with this plant food. So, it’s an ideal choice for squash, kale, peppers, lettuce, tomatoes, etc. You can also use it for herbs like rosemary, oregano, parsley, sage, and more.

3. AgroThrive Organic 3-3-2

Do you want to improve your cucumber plant and soil quality without synthetic chemicals? You can apply AgroThrive organic fertilizer to get an authentic gardening result.

It is known as the world’s best organic bio-fertilizer. It has an excellent 3-3-2 NPK ratio, which is suitable for your cucumber plant to provide enough nutrients and maintain a low nitrogen level. 

AgroThrive fertilizer helps to feed your plants properly and the materials of this bio-fertilizer are more helpful to improve your plant and the soil quality. This is because it enriches bacterial activity and helps to release nutrients from the soil. It will protect your plant from harmful insects or other microorganisms that can cause disease.

Just take some water and mix this fertilizer with water, and then apply it to the soil. The volume of fertilizer should be 20z-40z, and the water will be 1 gallon.

Next Read: Right Ways to Plant St Augustine Plugs

4. Miracle-Gro 2000422 Plant Food

Miracle-Gro 2000422 is a fine choice for your hungry cucumber plants. This plant food contains nutrients like Nitrogen, Manganese, Magnesium, and other nutrients to fulfill the needs of your plants. With proper use, your cucumber plants will get these nutrients from the fertilizer and start utilizing them.

The usage of this plant food is not only limited to cucumbers. If you have vegetables in your garden other than cucumbers, you can use this fertilizer on some of them as well. It’s water-soluble, so it won’t be troublesome work to mix and spread it evenly.

You can apply it to your garden with a Miracle-Gro garden feeder or if you don’t want to pay for the feeder, you can use it with any watering can available. Don’t worry about burning your plants; they will not burn them if you correctly use the fertilizer.

5. Greenway Biotech 8-16-36 Powder

Greenway Biotech 8-16-36 cucumber fertilizer comes with nutrients to promote better cucumber harvest. It has an amazing NPK level of 8-16-36 which contains a large amount of Potassium and less Nitrogen. It contains other nutrients like Copper EDTA, Boron, Iron EDTA, Molybdenum, and Zinc EDTA.

If you are concerned about whether the fertilizer will suit your hydroponics or not, to make you calm, this Greenway Biotech fertilizer is suitable for both soil use and hydroponics. And don’t worry about safety because it contains no harmful or heavy materials.

Being a water-soluble fertilizer, you don’t need to go through a troublesome application process like other types of fertilizers. It’s easy to mix it with water and distribute it to the cucumber plants evenly. Simply apply the fertilizer and expect a basketful of cucumbers in the harvesting season.

6. Dr. Earth Organic Vegetable Fertilizer

Dr. Earth organic fertilizer is a suitable fertilizer for your cucumbers and some other vegetables. It also suits both summer and winter crops. This fertilizer contains organic ingredients and primary plant nutrients to eliminate the nutrition needs of your cucumber plants.

If your garden remains lively because of your kids and pets, don’t worry about their safety. This fertilizer is a Non-GMO project verified one and it doesn’t contain chicken manure, sewage sludge, synthetic chemicals, or toxic ingredients.

It is rich in multi-minerals, carbohydrates, proteins, trace elements, and humic acids that improve the soil condition to give you a basketful of cucumbers in the harvesting season. So, apply this organic vegetable fertilizer properly, take care of your plants, and hope for a better harvest every time.

7. Down to Earth 4-4-4 Organic Fertilizer

If you are looking for a fertilizer for cucumbers that has balanced nutrients then you should check out this organic garden fertilizer. This 4-4-4 garden fertilizer has an amazingly balanced ratio of Nitrogen, Phosphorus, and Potassium. This fertilizer ensures powerful nutrition for your cucumber plants.

The use of this fertilizer is not limited to cucumbers only. You can use this fertilizer for summer tomatoes or fragrant herbs. And don’t worry about application time; you can use it throughout the growing season.

The fertilizer is OMRI listed for organic use. So, you don’t need to be concerned about what ingredients you are using on your vegetables; the fertilizer is safe to use.

The fertilizer packaging contains 5 lbs of fertilizer which is enough to feed a lot of cucumber plants. So, apply the safe fertilizer to your garden and wait for delicious cucumbers.

8. The Old Farmer’s Almanac Plant Food

Organic granular fertilizers can be an excellent choice for your garden. This OMRI listed The Old Farmer’s Almanac organic plant food is an ideal granular food for your cucumbers. This excellent granular plant food is specially formulated for vegetables, organic tomatoes, herbs, fruits, trees, and shrubs. Being in granular form, it’s not difficult to apply.

This fertilizer has both quick and slow-release features. So, it gives nutrients to your cucumbers in a fantastic way. The 8-4-8 NPK ratio gives a balanced level of nutrients where 8% Nitrogen helps in the plant’s growth and achieving beautiful color, 4% Phosphorus helps in producing better blooms and healthy fruits, and 8% Potassium helps your plants develop a robust root system.

This fertilizer gives your cucumber plants protein-based nutrition. And it’s OMRI listed for organic use. You can use this fertilizer for not only outdoor but also indoor organic gardens.

9. MasterBlend 4-18-38

If you prefer a water-soluble fertilizer for your cucumbers, you should check out this 100% water-soluble MasterBlend vegetable fertilizer. One good thing about this fertilizer is that you can easily mix it with water and apply it to the plants. Being water-soluble, it will be easy to apply. And with proper technique, it can be applied evenly to your cucumber plants.

Cucumbers don’t require a lot of Nitrogen. And this fertilizer has an amazing 4-18-38 NPK ratio. So, it’s a great way of giving your cucumbers enough nutrients while maintaining a low Nitrogen level. It contains vital nutrients to promote better health for your cucumber plants.

You can use this fertilizer on your cucumbers and on tomatoes and other vegetables. If you have a garden where cucumbers, tomatoes, and other veggies share the same nutrients, it can be an excellent choice for your garden.

How to Choose the Best Cucumber Fertilizer?

Not all fertilizers will work the same way for your cucumbers. You will get the best results from a specific fertilizer if it can fulfill the maximum needs of your cucumber plants. To choose the best fertilizer, consider the following factors while purchasing.


No matter which fertilizer you choose for your cucumbers, the first thing you should be concerned about is safety, especially if you have kids and pets.

If the fertilizer contains synthetic chemicals or toxic ingredients, it’s not just harmful to kids but to you and the environment.

That’s why you should double-check the ingredients mentioned on the packaging of the fertilizer and make sure there are no hazardous materials on the fertilizer. And even if you choose a fertilizer that contains some toxic ingredients, make sure to keep it out of the reach of children and pets.

NPK Ratio

If you are a complete beginner, let’s clarify a term first. The NPK ratio means the ratio of Nitrogen (N), Phosphorus (P), and Potassium (K) present in the fertilizer. You will find it as three numbers, like 4-4-4 or 5-10-10, in the fertilizer packaging. The numbers mean the ratio for the respective nutrients.

Now let’s talk about the nutrient requirements of cucumbers. Cucumbers don’t need too much Nitrogen. They require less Nitrogen compared to the other two nutrients in the fertilizer. This tells us that the number of Nitrogen (the first number) in the NPK ratio should be less compared to other nutrients.

So, to get the best results from a fertilizer, you need to ensure the number of Nitrogen is low compared to other nutrients. Additionally, if the fertilizer has an overall higher level of Nitrogen, avoid that one.

Types of Fertilizer

There can be four types of fertilizers available for cucumbers. Let’s take a look.

Granular: They look like tiny pellets. These small fertilizer pellets will work slowly compared to liquid types. The benefit is that it will release the nutrients slowly and keep feeding the plants for a longer time.

Liquid: Your plants will absorb these types of fertilizers quite easily. You will find this is in ready-to-spray or concentrated form, requiring you to mix it with water to apply. The downsides of this type of fertilizer include getting washed off easily and having to feed the plants frequently.

Spikes: This type of fertilizer will work slowly. Spikes are loaded with dry nutrients. You need to push them into the soil and they will gradually release the nutrients and provide food for your cucumbers.

If you are cultivating the cucumbers in a container, this can be a good option because it will provide the nutrients in a small area for a longer time.

Water-soluble: This type of fertilizer will look something like powder. This powder or granule will get dissolved in water quickly. Once dissolved, you can spread the fertilizer quickly and evenly.

Finally, you are the one who will be using the fertilizer, so we are leaving this mostly to your preferences.

Organic or Non-organic

While choosing the best cucumber fertilizer, a common thing that might cross your mind is which one to choose, organic or non-organic? Both have significant benefits. Let’s talk about them briefly.

Organic: While talking about organic fertilizers, firstly, you need to make sure they don’t contain any toxic materials. The ingredients of this type of fertilizer need to be collected from organic sources like bone meal, worm castings, chicken manure composting, etc. They can be a bit pricey compared to synthetic fertilizers.

Non-organic: Though there are chances of containing synthetic materials, don’t get scared at first sight. It can help you achieve a basketful of harvest. However, care should be taken while using the fertilizer, and you should keep an eye on the amount of fertilizer you use on the soil.

What Kind of Fertilizer to Use for Cucumbers?

If we are talking about types of fertilizers, you can choose liquid, granular, or other types depending on the soil condition, your plants, and your preferences. As we have said earlier that you need to choose a fertilizer that has a lower Nitrogen level compared to other nutrients. So, while choosing a fertilizer, make sure to check that out first.

Additionally, if we are talking about the best fertilizer for cucumbers, I would say it’s ‘well-aged compost’. It has a surprising level of Nitrogen, 2% Nitrogen only. Plus, it will slowly release nutrients for a long time and improve the quality of the soil.

If you learn the process of making compost, you can make it at home. I guess you can call that the best homemade fertilizer for cucumbers which will help you get rid of some organic trash and save a pretty penny on fertilizer ultimately.

When Should I Fertilize My Cucumbers?

You can fertilize your cucumbers in three stages. The exact time for fertilizing your cucumbers will depend on when you plant them. Because the first fertilizer application time is at the time of planting.

After planting, you will notice germination. And this is when you should start watering your cucumber plants because proper watering will help you get a better cucumber harvest.

The next stage of fertilization is when mulching is done around the cucumber plants. And finally, the last stage of fertilization will occur at intervals of two weeks as the plants develop. Use a fertilizer with the right combination of Nitrogen, Phosphorus, and Potassium, i.e., the NPK ratio.

How to Fertilize Cucumbers

Okay, after choosing the desired fertilizer for your cucumbers, you would probably want to apply the cucumber fertilizer dose. As we have said earlier that you can fertilize in three stages. Now, let’s see how to fertilize in each stage.

1. Fertilizing at the Time of Planting

Fertilizing at the time of planting will give the cucumber plants a good head start with nutrition. Here, you just need to put some nutrients in the planting hole to give your plants a good food source right next to their roots. The procedure of fertilizing will vary from transplants and seeds.

If you choose seeds, make sure to mix a sufficient amount of compost with the soil before doing anything else. If you choose transplants, compost is still a better option. Measure the approximate size of the transplant’s root ball and dig a hole roughly three times bigger than that.

Now, fill the area with a 50-50 mixture of compost and soil. For better results, you can put about ¼ cup to ½ cup of fresh worm castings in the planting hole.

2. Fertilizing at the Time of Mulching Around the Plants

The time for mulching begins when the seedlings start to pop up from the ground. And if you are starting by planting transplants, you can mulch it right away. It’s a great opportunity to boost the effectiveness of the mulch by applying fertilizer.

At the time of mulching around the plants, you need to put a layer of compost that is about 2 inches thick. And make it roughly 6 inches in diameter around a single cucumber plant. Additionally, you can mix some worm castings into it.

Take a ¼ cup of castings and mix them well. After that, apply the typical mulch you want to apply to your cucumber plants.

3. Regularly Fertilizing with Light Fertilizer Dose

After your cucumber plants are strong and established in the soil, you must regularly apply light fertilizer doses. Choose a liquid organic fertilizer and keep fertilizing them every two weeks. You need to continue it for eight weeks and the total application will be 4.

Apply regularly and lightly. Don’t let your plants remain hungry, and don’t over-fertilize; fertilize in a balanced way. Giving your plants very little fertilizer means keeping them hungry. You will not get satisfactory results out of this.

On the other hand, over-fertilizing may lead to higher growth of foliage but your plant will not give expected blooms. As a result, you may notice your plants are getting huge in size but not producing fruits as expected. Things can get even worse and your plants can die due to overfeeding.

Should I Use Non-Organic or Organic Fertilizer?

Let’s summarize what we talked about earlier. Generally speaking, organic fertilizers will work slowly but they will not contain any toxic materials. On the other hand, Non-organic fertilizers have a chance of containing some harmful materials but these fertilizers will work quite fast.

Using a non-organic or organic fertilizer may depend on the need for nutrients, your preferences, etc. So, we are leaving it to you. Depending on the situation, choose any fertilizer that you think will benefit your cucumbers the most.

Final Thoughts

Picking a fresh cucumber from the garden, putting some salt in it, and eating it right away may be easy, but growing mouth-watering cucumbers is not! It requires proper care and ensuring a good fertilizer.

In this article, we talked about some of our top picks and some helpful info about fertilizing cucumbers. So, besides taking proper care of your cucumber plants, give them a better fertilizer. And that is when our reviews of the top fertilizers for cucumbers will come in handy.

Written by Sean Stratton

Sean Stratton

Hi, I'm Sean, the senior editor here at Fertilizer Pick. I grew up on a farm in North Carolina and have grown fruits, vegetables, and trees since childhood. While I no longer live on a farm today, I still enjoy spending time on my garden and sharing my knowledge with friends and fellow garden enthusiasts.