Best Fertilizer Types For Geraniums: The Ultimate Guide To Choosing Types, Usage Methods, Amount Requirements, Frequency, And Benefits

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Quick Answer: Best Fertilizer Types For Geraniums

Geraniums are popular flowering plants that can be benefitted from regular fertilization. Synthetic fertilizers, including balanced fertilizers and 10-20-20 NPK fertilizers, support overall growth. Different organic options, including worm castings, bone meal, crushed eggshell, and seaweed extract support geranium blooms. It is preferable to fertilize them every four weeks during the growing season.

This is a comprehensive guide that will assist you in selecting the ideal fertilizer for your geranium plants.

I have brainstormed and gathered all the essential information you need to make an informed decision on fertilizers for geranium.

Read further to know more!

Best Fertilizers Types For Geraniums

Geraniums are one of the important spring bedding flowering plants that are easy to grow, beautiful, and release a fragrant smell.

It can be grown outdoors or in containers, including window boxes and hanging baskets. It is important to fertilize them during production to maximize growth.

The three essential nutrients required for geranium are nitrogen for healthy foliage, phosphorus to encourage blooms, and potassium for plant’s general health.

It also needs several macro and micronutrients, including calcium, iron, magnesium, manganese, copper, boron, and zinc to thrive.

It may require soil amendments to meet their nutrient requirements and ensure abundant blooms.

Also, it is important to choose the ideal fertilizers for having healthy and happy geranium plants.

Many organic and inorganic types work well for your geranium plants during the active growing season.

Here is a useful video for additional information on growing geraniums:

Next, let us discuss the different soil amendments that are suitable for the geranium.

Best Inorganic Fertilizers For Geraniums

Inorganic fertilizers, also known as synthetic fertilizers are mineral compounds that are specifically formulated to provide essential nutrients for geraniums.

It provides a quick boost of nutrients to plants.

Here are a few inorganic fertilizers that work well for geraniums:

1. Balanced Geranium Special For Geraniums

Balanced fertilizers with NPK values of 10-10-10 or 20-20-20 are suitable for flowering plants, including geranium.

It works for both outdoor and indoor geranium plants. It is available in both granular and liquid form.

How to Use/Apply?

  1. Apply balanced fertilizer– Wear gloves while handling the fertilizer. Sprinkle a scant teaspoon of fertilizer and spread it on a square meter area around the geranium plants.
  2. Mix well– Mix well with a rake and incorporate them into the soil.

You may check this video for additional information on NPK fertilizers:

Pros And Cons

Balanced fertilizer provides a good supply of all essential nutrients for the plants without promoting excessive foliage growth.

It supports the long-term health and sustainability of geranium plants.

2. 10-20-20 Fertilizers For Geraniums

Geranium plants may benefit from low nitrogen fertilizers with NPK values of 10-20-20.

It is recommended to use a pound of 10-20-20 fertilizers for every 100 square feet before planting. It is available in both granular and liquid fertilizers.

How to Use/Apply?

  1. Dilute the fertilizer– Follow the instructions and dilute the fertilizer.
  2. Apply the fertilizer– Apply the fertilizer to the soil around the base of the plants. Alternatively, dilute the fertilizer as instructed and apply it to the leaves of the geraniums using a sprayer.


10-20-20 fertilizer is versatile and provides control over the nutrient application. It helps to meet the nutrient requirement of geranium and encourages its blooming period.

Best Organic Fertilizers For Geraniums

Organic fertilizers are derived from natural sources and provide nutrients for geranium in a slow-release manner.

It promotes flowering and root growth in the geranium. It needs less frequent application compared to synthetic fertilizers.

Here are a few organic fertilizers that are suitable for geranium:

1. Bone meal For Geraniums

A bone meal is a meal or powder made from ground animal bones. It can be used to replenish calcium and phosphorus in the soil.

It helps in boosting geranium health and producing plentiful flowers.

How to Use/Apply?

  1. Sprinkle bone meal– Sprinkle bone meal around the base of the plants. It is recommended at the rate of 10 pounds for every 100 square feet. You may also consider a small amount inside a planting hole before planting.
  2. Water the garden– Water the soil after adding bone meal. It helps in incorporating fertilizers into the soil.

Check out this video for tips on using bone meal fertilizer:

Pros And Cons

Bone meal is a soil amendment that can be used for balancing nitrogen and increasing phosphorus in geranium plants. It releases nutrients throughout the growing season.

But, it may attract animals and is not suitable for all soil pH levels.

2. Worm Castings For Geraniums

Worm castings are eco-friendly fertilizers rich in organic matter and microbes providing essential nutrients for geranium.

It can significantly enhance the growth, health, and blooming potential of geranium plants.

How to Use/Apply?

  1. Add worm castings– Sprinke a tablespoon or two of worm castings around the base of the geranium plants. Mix well to incorporate the compost. Water the soil and top-dress with worm castings as required.
  2. Add casting to container plant– Add a quarter cup of castings to the top of the soil in the container containing geranium. You may also mix one cup of castings with four cups of potting soil and planted the geranium.

Here is a video on growing worm castings:

Pros And Cons

Worm castings provide beneficial microbes and slowly release nutrients to the soil to feed geranium plants.

It also helps in improving soil aeration, soil structure, and increasing water retention.

3. Crushed eggshells For Geraniums

Eggshells are rich in calcium and are beneficial for flowering plants, including geranium. It helps in promoting geranium growth and improves soil health.

It can be store-bought or made at home.

How to Use/Apply?

  1. Crush the eggshells– Save the eggshells, rinse them thoroughly, and crush them into small pieces.
  2. Incorporate into potting soil– Mix crushed eggshells into potting mix or soil before planting or repotting your geranium.
  3. Apply as a top dressing– Sprinkle a layer of crushed eggshells around the base of the plants.

Click this video for quick tips on using eggshells for your garden:

Pros And Cons

Eggshells are rich in essential nutrients and provide a sustained supply of nutrients over time for geranium plants.

Additionally, it helps in improving soil structure and moisture retention. It can also deter garden pests from troubling the plants.

4. Seaweed Extract For Geraniums

Seaweed extract is a concentrate obtained from different species of seaweed or marine algae. It is abundant in essential nutrients and helps in boosting geranium growth.

It can also be supplemented with compost for a comprehensive nutrient profile.

How to Use/Apply?

  1. Dilute the seaweed extract- Dilute the seaweed extract according to the instructions on the product label.
  2. Pour the diluted seaweed extract– Use the diluted seaweed extract and pour it around the base of the plants. It can also be applied as a foliar application directly on the leaves.

You may watch this useful video for additional information on growing seaweed extract:

Pros And Cons

Seaweed extract adds nutrients to geranium plants and provides better resistance to stress. It helps in improving the defense of plants and protects them from pests and diseases.

When And How Often Do I Fertilize Geraniums?

The timing and frequency to fertilize geraniums will vary depending on the type of fertilizers and the place where it is grown. You may check the label for detailed instructions.

Outdoor plants

New plants prefer 5-10-5 fertilizers for their first feeding as it needs to develop strong root structures.

You may skip the first fertilizer dose when transplanting outdoors if the compost is incorporated into the soil.

Many growers use constant fertilization with water-soluble fertilizers. Apply adequate water to prevent the buildup of salt.

It is preferable to give them on a bi-weekly or every four weeks during the active months of growth. But, few species are heavy feeders and require more feeding.

Switch to a fertilizer high in potassium when the plants start to bloom to encourage a long blooming season.

If you observe changes in leaf color, legginess, or bloom color, you may adjust the feeding. Avoid over-fertilizing as it may lead to chemical burns in the plants.

Also, you need to cut back on feeding when the hardy geraniums are perennials and go through a dormant phase. It can be again fertilized in the spring to encourage blooming.

Container plants

Geraniums grown in containers may require more fertilizers compared to plants grown in garden beds.

It prefers a balanced 10-10-10 fertilizer every two weeks. Fertilize them only in the spring and summer when the plants are actively grown indoors.

Liquid Vs Granular For Geraniums: Which is Better?

Both granular and liquid fertilizers can be used for geraniums. It depends on your preference, current condition, and stage of plant growth.

Granular fertilizers are slow-release granules that can be sprinkled around the base of the geranium plants. It can slowly deliver nutrients for the plants over a long time.

It may be effective at nourishing the roots of geranium plants. It requires fewer applications and tends to offer longer-lasting effects.

Liquid fertilizers tend to work best for geraniums as it is less likely to be leached from the soil.

It provides immediate availability of nutrients to plants, especially during periods of rapid growth or when they exhibit signs of nutrient deficiencies.

It can work either as a root absorption or a foliar spray.

Provide plenty of water after using liquid-soluble fertilizer to avoid the buildup of fertilizer salts.

In summary, both granular and liquid fertilizers can be suitable for geranium. You may choose a combination of both types to provide a comprehensive nutrient regimen for the plants.

Check out this video for differences between granular and water-soluble fertilizers:


Can you use coffee grounds for geranium?

Yes, coffee grounds can be beneficial for geranium but in moderation. Too much coffee grounds may make the soil too acidic which is unfavorable for geranium. One of the safest ways of using coffee grounds is by adding to compost. More research studies are required.

Is Epsom salt good for geranium?

Yes, Epsom salt can be beneficial for geranium plants especially when the soil is deficient in magnesium. Mix one tablespoon of Epsom salt in a gallon of water. Water this plant every 2-3 weeks for providing magnesium.

What are the signs of nutrient deficiency in geranium?

The signs that geranium has low nitrogen include slow growth and yellow leaves. The phosphorus deficiency indicates leaves turning dark green or reddish to purple. The geranium deficient in potassium have weaker stems.

Bottom line

Hopefully, this guide has provided you with valuable pointers to help you shortlist the fertilizers for your geranium plants.

I am interested to hear your suggestions in choosing the fertilizers for the plants.

Do share the guide with your friends and family to help them out too!

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