Fertilizer for Hot Pepper Plants: Easy Guide to Happy Peppers

If you have just started growing hot pepper plants, the amount of information available online can be overwhelming. There is so much to think about and every gardener has a different technique or favorite product that they think is the best. There are many different fertilizers available in hardware stores, garden centers, and online.

Tomato fertilizer tends to work well for hot pepper plants. Without some kind of fertilizer, there is a high chance that your plants will not grow well or produce a high crop yield. To give them the best chance of survival, you should regularly water and fertilize your hot pepper plants. 

There are more than 20 different varieties of hot peppers, in the genus Capsicum. All of these species require lots of sunlight, fertile and well-drained soil, and warm temperatures to grow sufficiently. 

Why do you need to fertilize?

If you want your plants to grow well, fertilizing them is one of the most fundamental steps to take. Fertilizers are a liquid food source for your plants, providing the soil with the essential nutrients that the plants need to grow.

They often increase the water capacity of the soil, meaning that the soil has higher water content. They can also improve the airflow throughout the soil, helping to prevent root rot. 

As plants grow, they extract nutrients from the soil. Fertilizer helps to replace the nutrients that have been absorbed by the plant. This helps to ensure that the soil quality is good and optimal for plant growth. The plant requires different things at varying points throughout the year and its life cycle. 

Peppers need a lot of nitrogen when they are initially growing. This helps them to create healthy and vibrant leaves. Later on, their nitrogen requirements drop, but they need more phosphate and potassium to grow healthy fruits. 

Fertilizer grades

Fertilizer packaging should have a 3 digit number printed onto the side. This is indicative of the ratio of the three key nutrients in the fertilizer liquid. The biggest elements in fertilizer are nitrogen, phosphate, and potassium, and the numbers represent these in this order. The most common ratios are 3-5-5, 5-5-5, and 2-3-1. 


Nitrogen has the chemical symbol N. It is essential for the growth, development, and reproduction of plants. In the portion of the plant above the soil, a healthy plant should have 3-4% nitrogen in its tissues.

Nitrogen is a major part of chlorophyll, which is vital for photosynthesis. It is also the main part of amino acids, which are used to build proteins. These can be structural or enzymatic components of the plant. Nitrogen is also a key part of the nucleic acids in DNA, meaning that it is vital to the survival of plants. 


This is the form that phosphorus is added to the soil. Phosphorus is also used in photosynthesis and the creation of DNA. Phosphorus is also found in RNA, meaning it is vital to protein synthesis.

Some growth factors have been linked to phosphorus in the soil. These are the stimulated development of the roots, increased strength in the stalks and stems, and improved flower formation and production of seeds. Plants with sufficient phosphorus levels have been seen to mature earlier, be of higher quality, and be more uniform in appearance. Phosphorus is also believed to give the plant increased levels of resistance to plant diseases.


This is required for all aspects of plant reproduction and growth. It is particularly vital to the movement of water and nutrients around the plant.

Potassium has been linked to increased crop yields for a multitude of reasons. It helps to improve the plant’s resistance to drought and increases the growth of the roots. Potassium reduces lodging and builds cellulose, while simultaneously activating at least 60 growth enzymes.

It is vital to photosynthesis and helps to translocate the sugars and starches around the plant. It can also help to increase the protein content of plants and reduce water loss and wilting. 

Other nutrients

There are elements found in lesser quantities that are also vital to the healthy growth of your peppers. These include calcium and magnesium. Calcium is vital to cellular development, particularly in the leaves and fruits. You should ideally look for a fertilizer that contains calcium. If you cannot find this, add some bone meal to your soil.

Magnesium is used to produce vibrant green leaves. If your plant is deficient in magnesium then the growth can be stunted. If your fertilizer does not contain magnesium then you can add Epsom salt to the soil. Combine 2 tablespoons of Epsom salts with tap water in a large spray bottle. Shake vigorously until the salt crystals have dissolved. 

This can also be applied directly to the leaves and stems of your pepper plants. You should soak the leaves thoroughly. This helps to keep the plant strong and prevents weaker and paler leaves from growing. Experts recommend doing this once every 2 weeks. 

If the leaves ever appear crinkled and bubbly, or if the ends of the chili pepper have sunken and dark areas at the tip, this suggests that your plant needs more phosphorus and calcium. Use bonemeal or Cal-Mag to supplement the soil. You are likely to only need to do this once per month. 

Your fertilizer may also include beneficial bacteria such as bacillus licheniformis and bacillus megaterium. These are colony-forming bacteria that help to keep your soil healthy and promote good plant growth. 

Types of fertilizers

As we have already mentioned, your plants will have different needs at different points in their lives. The fertilizers for each stage will need different formulations and you cannot just use the same one the entire time. 

If you do not want to worry about finding different fertilizers, we like FoxFarm’s Liquid Nutrient Trio Soil Formula. This comes as 3 1 pint bottles called Big Bloom, Grow Big, and Tiger Bloom. Grow Big should be used at the beginning of growth to facilitate healthy green leaf production. As soon as you see buds or flowers appearing, you should swap to Tiger Bloom. Big Bloom can be used during all growth cycles. It will help to facilitate nutrient cycling and will help to heal any damage to the root systems. 

Stage one fertilizer

This is a nitrogen-heavy fertilizer to help with the growth of green leaves. You should ideally look for an organic and water-soluble fertilizer for ease of use.

Miracle-Gro Performance Organics Plant Nutrition has 11% Nitrogen, 3% Phosphorus, and 8% soluble potash (K2O). It is water-soluble and comes in a container that can be attached to your garden hose for ease of use. 

If you prefer fertilizers that you can mix into the soil, we recommend opting for the Epsoma Garden Tone. This gives you a lot of nutrients such as nitrogen, combined with beneficial bacteria to increase soil health. 

Stage two fertilizer 

This is used for the blooming stages when the plant is growing buds or flowers. This fertilizer should be lower in nitrogen but high in potassium and phosphorus. This will help the pepper pods to grow properly. High nitrogen fertilizer could potentially reduce the crop yield of the plant in favor of growing more leaves. 

Our favorite stage 2 fertilizer is Neptune’s Harvest Fish and Seaweed Fertilizer. The ratio is 2-3-1, making it ideal for the later stages of growth. This fertilizer is made from freshly caught fish and has a huge amount of beneficial nutrition for your hot peppers. It has a mildly fishy aroma, so be warned. There is no magnesium or calcium in this fertilizer and so you may wish to supplement the soil with these compounds too. 

Alternative fertilizers

You can reduce your household waste and feed your plants at the same time. Used coffee grounds make a fantastic fertilizer for hot peppers. Sprinkle them over the soil or add them to your watering can to reap the benefits. This will also help to keep snails and ants away from the crops. 

Eggshells are another natural fertilizer. Place them in a glass of water and allow them to sit there for a few days, allowing the lime to seep into the water. Pour this water over your plants. 

How often should you fertilize your peppers?

If you are serious about your pepper growing then you will need to fertilize according to a schedule. This prevents you from over- or under-fertilizing your plants. Experts recommend adding 30% nitrogen fertilizer before you sow your pepper seeds. Plant the seeds, and wait 2 weeks. Once this time has elapsed, add a further 45% of the nitrogen fertilizer. As the pepper harvest is ending, use the remaining 25% of the fertilizer. 

You should begin fertilizing your peppers for the first time once their first leaves have emerged. Pepper seeds should be planted in a special seed starting soil, which does not contain nutrients. This is why the fertilization process should begin as soon as growth is visible.

Around 2 weeks after the sprout has appeared, the initial layer of fertilizer should be applied. Depending on the potency of your commercial fertilizer, you should dilute it for the initial application. Generally speaking, this should be diluted to about 50% concentration. This prevents the root system from being overwhelmed. 

If you have planted your pepper seeds in compost or a potting mix, this soil will already contain a high concentration of nutrients. In this case, you do not need to apply fertilizer until the peppers have been moved to their final planting location. 

The frequency with which you should fertilize your peppers will vary according to the specific fertilizer you are using. There will be information written on the packaging dictating the relevant actions to take. As a general rule, most fertilizers will need to be applied either weekly or bi-weekly. 

We cannot stress enough how important a regular fertilization schedule is. This will help to keep the levels of soil nutrients consistent and will provide the optimal conditions for pepper growth. 

What happens if you over-fertilize?

If you give your plants too much fertilizer they can experience something known as nutrient burn. This will be evident on the plant’s leaves, as they will begin to develop brown spots towards the edges. This is due to an excess of nutrients that chemically burn the leaf. 

Brown spots on leaves are often symptomatic of disease too, so you should attempt to rule this out before assuming it is caused by fertilizer. If you notice this nutrient burn occurring, you can flush the soil to prevent any further damage from setting in. 

To flush the soil, you simply need to water the plants without any fertilizer. Ensure the pot has drainage holes in the base to allow the water to escape. If it does not then you will waterlog your roots and your plant will develop root rot. This flushing process will force excess minerals and salts from the soil. Leave the plant sitting in the sun to dry out and drain.

If you want to flush the soil in flower beds or in the ground, just water the plants with plain water instead of adding fertilizer. Do this for a few weeks and the nutrient level will decrease over time. 

Soil pH

While the nutrients are vital to the health and growth of your plant, the soil will always be more important. The pH of the soil is a measure of how acidic or alkaline the ground is. The ideal pH range for peppers to grow is between 5.8 and 6.2, meaning that they prefer a mildly acidic growing medium. 

An incorrect soil pH could result in a nutrient lockout. This is when the roots of your plants cannot uptake nutrients from the soil, resulting in a reduced crop yield and poor plant health. If you suspect that this is the case, then you may wish to conduct a pH test on your soil.