What Are The Natural Phosphorus Sources For Your Plant?

Phosphorus is equally as important as Nitrogen and Potassium for a plant to grow flowers or fruits. This will cause you to think, what are the natural phosphorus sources for your plant? 

10 natural materials embedded with high amounts of phosphorous are: 

  1. Rock phosphate 
  2. Bone meal
  3. Bat guano
  4. Vermicompost
  5. Crab meal
  6. Seabird guano
  7. Chicken manure
  8. Compost
  9. Cottonseed meal
  10. Pig manure

Let us first find out what phosphorus does for your plants before reading about the sources. 

Why Is Phosphorus Important For Your Plants?

All plants require phosphorus as they use it for a range of reasons. Examples of a few are cell division, photosynthesis, transfer, and storage of energy, and growth of new tissue, among other reasons.

Without phosphorus, plants are unable to carry out their production cycle and its purpose. Phosphorus is also a critical part of the RNA which is responsible for reading the genetic code for protein and other compounds.

It is the main component of ATP which is formed during photosynthesis. As you can see there are many plant components such as DNA, RNA, and ATP that rely on phosphorus for their daily function. The importance of phosphorus cannot be stressed enough. 

Phosphorus Deficiency In Plants

A deficiency of phosphorus is not very easy to diagnose in plants. But you can tell if your plants are taking longer to mature or if their growth is stunted. Once this happens, there is no going back and reversing the damage. Even if you start applying phosphorus to the soil.

A deficiency of phosphorus also leads to several problems for your plants. It can lead to a lack of shooting or even stunted growth. The deficiency usually affects older growth first by making the leaves appear dark and dull. With a deficiency in phosphorus, some crops like corn develop an abnormal color. 

The leaves and stem of the plant turn to dark bluish green. Also, a deficiency in phosphorus can be transferred from the old plant tissue to the new plant tissue.

Excess of Phosphorus Can Be Harmful to Your Plants! 

Yes, too much of a good thing (phosphorus) can be bad for your plants! 

Excess phosphorus induces discoloration and yellowing of the leaf or leaf veins. Garden and agricultural water runoffs can go on and pollute water bodies. These can bring about algae blooms which deplete the water oxygen levels and kill fish and other aquatic organisms.

It does not necessarily mean that you have to add phosphorus to every scenario. Some fruit trees do not need large fruit or flowers and the phosphorus in the soil should be adequate.

Excess phosphorus can have dire ecological effects, so take care of how and where you use it.

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What Are the Natural Sources Of Phosphorus for Plants?

There are many synthetic versions of phosphorus in the form of store-bought fertilizers. But if you want to go green here are some natural sources of phosphorus that you can use for any plant. 

#1- Rock Phosphate

Rock phosphate is a premium source of phosphorus, yet it is difficult for plants to absorb. It is hard to break down because the calcium and phosphorus atoms are tightly fixed together in the rocks.

Using the N-P-K ratio of 0-2-0 in rock phosphate makes it a suitable source for phosphorus. Utilizing this type of phosphorus has the advantage that it is cheaper than other sources of phosphorus.

Note- Phosphorus is most present in soils with a pH between 6.0 to 7,0. Before running off and assuming you need a phosphorus supplement, test the soil first.

How To Apply?

The best time to give your plants phosphorus is in the spring. Rock dust is applied at the rate of 10 pounds per 100 sq ft. This is based on the soil type in your garden or farm.  

Soils that have severe phosphorus depletion have a maximum of 50 pounds of phosphorus per 100 sq ft. You can go the extra mile here and mix the phosphorus with compost and then add it to your garden.

Rock phosphorus works best if you have acidic soils. Acidic soils absorb phosphorus more easily and because of that, the roots have free access to the mineral. For non-acidic soils, compost should be mixed into the soils first as organic matter is naturally acidic.

#2- Bone Meal

Animal bones are steamed and then crushed to become a bone meal. It is a by-product of the slaughtering process and is great to put waste products to use. Bone meal is a fast-acting and high phosphorus source with an N-P-K ratio of 3-15-0.

It takes a few months for the microbial process in the soil to release the phosphorus in the bone meal to the plants. Calcium is also present in the bone meal, making it great for soils lacking in phosphorus and calcium. 

How To Apply?

Add the bone meal during your soil preparation. You can add it to your compost or use it as fertilizer, mix it in thoroughly before applying it. Spread it over the area to be used and dig it in. Be careful so you do not damage any roots as you go along. 

To encourage fruiting or flowering plants use it once at the beginning of the growing season, and then again once or twice. After applying the bone meal, give the plants a good soaking with water. 

#3- Bat Guano

Bat Guano is another excellent source of phosphorus, more suited for small-scale gardens. Not as superior as seabird guano in terms of nutrition. However, it is more readily available. The nutrients in bat guano are more water-soluble. 

Thus it is better to use it as a foliar spray. Also, it makes a good weed killer. 

How To Apply?

It comes in a powder form that can be sprinkled around the base of your plants. After applying, give the plant a good watering. You can also mix the powder with water to make a solution. Spray this solution onto your plants and allow them to absorb it better!

The solution is also applicable as a spray for your plants. A compost made from bat guano is also available. In comparison to other manures, small amounts of bat guano are used in small quantities.

#4- Vermicompost

This is a distinct way of composting in which earthworms are used to improve the compost material and produce a better product. Vermicomposting helps to increase the nutrients and phosphorus in the compost.

Earthworms and microorganisms are useful in this process. It occurs by feeding organic waste to earthworms, which break it down into a granular form and pass it out. 

How To Apply?

This is very easy to apply and you don’t have to worry about poisoning the environment. All you have to do is mix the following.

  • One part of garden soil
  • One part coco-peat
  • One part vermicompost
  • Banana peels are a great addition

Mix and it’s ready to use in your indoor pot plants and your outdoor containers.

#5- Crab Meal

This is a very different type of phosphorus supplement! Crab meal consists of ground crab, shrimp, or other mollusks that make a meal. The shells of these crustaceans are used, although sometimes other types of mollusk waste are also used.

It is a very good source of phosphorus, but it can be difficult trying to get your hands on this type of fertilizer. It works well in enhancing soil fertility and bacterial activity. 

How To Apply?

Crab meal can be added to your compost, you can spread it over your mulch too. It will add much-needed nutrition to your plants and again it is eco-friendly and natural. 

#6- Seabird Guano

Isolated islands with low rainfall and hot temperatures are the best places to look for seabird guano. Seabird guano has a high concentration of nutrients and phosphorus, as well as nitrogen and calcium. This is because their diet exclusively includes crustaceans and fish. 

How To Apply?

Apply at the rate of 2.5 to 5 pounds per 100 sq ft in new soils. Carefully mix into the top 3 inches of soil and evenly distribute. You can while transplanting plants, add a tablespoon into the holes. 

When the growing season is in progress, you can give 1 to 2 oz of fertilizer per month. 

#7- Chicken Manure

Yet another good source of phosphorus is chicken manure. Besides being a good source of nutrients, it does a world of good for the soil and the plants.

Chicken excretion that has been composted releases micronutrients and macronutrients slowly into the soil.

Besides increasing the soil’s capacity to hold water, it improves soil aeration and drainage. It reduces fertilizer leaching and there is an overall improvement in soil quality.

The soil’s biodiversity undergoes improvement as organic matter is a food source for soil bacteria. The bacteria break down the organic nutrients into a form that is more available to plants.

How To Apply?

To degrade the chicken waste, put the waste into a compost container. Keep it well watered and give it a mix or toss it every few weeks. It takes 6 to 9 months to properly compost the waste. Once ready you can spread it around your garden.

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#8- Compost

Various garden waste is useful in creating compost. These include hedge clippings, lawn clippings, and fruit and vegetable scraps (organic material) from your kitchen.

It’s a very common type of compost that most people make as it’s easy and a great way of using up organic waste.

It helps in holding moisture, nutrients, and air. Chicken manure makes an excellent mulch and a cheap way in which to improve your soil. It adds richness to the soil and makes a positive impact on the plant.

How to Apply?

Apply your compost as a mulch, as a top dressing, or as a compost tea. Add a little compost in the plant holes when planting new plants. Or when the growing season has started you can put a little around the base of your plants, potted or ground-bound. 

#9- Cottonseed Meal

Cottonseed meal is a fertilizer that exhibits slow release into your soil. You might have guessed that it is a by-product of cotton. Cottonseed provides the plant with phosphorus as well as nitrogen, potassium, and small amounts of other nutrients.

Cottonseed meal also aerates the soil, prevents runoffs, lightens heavy soil, and promotes better blooming in garden plants.

How To Apply?

You will need between 2 to 4 pounds of cottonseed meal for every 100 sq ft of land. You can use up to 8 pounds of fertilizer without worrying about adverse effects. Use it as a top dressing as long as you make sure to mix it in carefully and thoroughly.

#10- Pig Manure

There are many nutrients that are beneficial to plants that can be present in pig manure. It is a good source of nitrogen, potassium, and phosphorus.

Plus, there is no need to compost this dung. It can be useful as an additive to the soil, to improve the soil as well as provide nutrients to the plants.

How To Apply?

Although many people use it as is, it is at its best when you compost it. Allow it to decompose in a warm dry area for some time before using. The process of composting will also kill any harmful bacteria that could affect your plants. 


Making sure you always replenish your soil with natural phosphorus-rich material is essential to having healthy plants. You could use store-bought synthetic phosphorus substitutes, but your plants may not react as well as they would act to natural material. 

Natural phosphorus sources for plants are Rock phosphate, Bone meal, Bat guano, Vermicompost, Crab meal, Seabird guano, Chicken manure, Compost, Cottonseed meal, and Pig manure. 

You can source most of these materials through a supplier from a farm. Or you can source and make them in your garden! 


What is more important for plants, phosphorus, nitrogen, and potassium?

Actually, all three are important for your plants. They each have a different role and a lack of either one of them will lead to ill effects in your plants. Ideally, all three should be present in decent quantities in the soil and replenished when levels become depleted.