How To Fertilise Hot Pepper Plants

When cultivating chilli peppers at home, it's essential to provide your plants with everything they need to flourish at every point throughout the growing season. This goes much further than just supplying them with water, warmth, and light; Capsicum plants often need a little helping hand in the form of fertiliser to perform to the best of their ability. But what fertiliser should you go for, and how much should you administer? Don't worry! We’ll break down everything you need to know about fertilising pepper plants so you can enjoy top-quality hot peppers in no time.

What is the best fertiliser for hot pepper plants?

With so many fertilisers on the market today, it can be a little tricky to figure out which are most suitable for your pepper plants. It's possible to purchase time-release fertiliser to feed your plants throughout their entire grow cycle. However, this isn't a viable option for all plants. Before looking to purchase additional fertiliser, it's best to test the nutrient level of your soil first. After all, the nutrient content of organic compost is going to be much different than that of the dirt in your back yard. From here, you can fine-tune precisely how much—and of what kind of—fertiliser to use, without damaging your plants.

The most common fertilisers contain the macronutrients nitrogen, phosphorus, and potassium. When administered, they provide almost everything your plant is after, allowing them to flourish effortlessly. When browsing for fertilisers, you will regularly see three numbers in a row; 5-10-10, for example. These represent the percentage of nitrogen, phosphorus, and potassium, respectively, per bag. While these numbers can vary among different products, it's a uniform and easy descriptor to keep an eye out for when browsing for fertilisers.

Primary and secondary nutrients

Although we’ve touched on them briefly, what nutrients do your pepper plants need to survive and thrive? And how exactly do they help?

By dividing nutrients into primary and secondary categories (i.e. macronutrients and micronutrients), we can get to the bottom of what your plants are hungry for.

Primary nutrients

Let’s start with the macronutrients—those your plants need in the highest quantities.

Nitrogen

Essential to the photosynthesis process, nitrogen is a hugely important element in the production of foliage and maintenance of overall plant health. Oftentimes, soil tends to be deficient in nitrogen, so it’s essential to get the levels right so your pepper plants get off to a good start.

Phosphorus

Phosphorus allows your plants to absorb energy from the sun for a much healthier and more resilient growing cycle.

Potassium

Potassium regulates growth and ensures the movement of water, nutrients, and carbohydrates throughout the plant itself. Without proper levels of potassium, photosynthesis can be negatively impacted.

Secondary nutrients

Although deemed “secondary”, these nutrients are just as important as those above, only they’re needed in smaller amounts.

Calcium

Calcium promotes robust development within pepper plants, and is vital to the overall health of your plants. It's unusual for soil to be low in calcium, but it can be easily amended through the use of bone meal.

Magnesium

Magnesium is vital to chlorophyll production, germination, and fruit production. To promote better health for your plants, magnesium should be used sparingly, as too much can cause irreparable damage, and too little can stunt growth as well. A fine balance is needed to ensure the best conditions for the plant.

A note on Epsom salt

To provide plants with a huge hit of magnesium, some turn to Epsom salt. However, this is a hotly disputed method of delivering nutrients to plants. While some believe it helps to improve pepper production and reduce the risk of blossom rot, others suggest the massive surge of magnesium damages the plant, causing issues such as leaf scorch and even impacting the flavour of the resulting peppers.

With that said, we do not recommend it.

How often should you fertilise hot pepper plants?

Like most things in life, timing is very important when it comes to fertilising pepper plants. As mentioned, overdoing it can only lead to damaged plants and subpar fruits. So, what is the best regime for feeding your chillies?

As a rule of thumb, fertiliser should be administered either every week or fortnightly. This often depends on the type of fertiliser being used. Thankfully, the packaging on your product’s container should offer sufficient guidance in terms of timing. Be sure to follow the recommendations and keep a strict schedule, and you can’t go wrong.

When to fertilise chilli pepper seedlings?

Feeding plants that haven't had the time to develop will undoubtedly spell disaster. With this in mind, it's best to wait roughly two weeks after the seed has sprouted, or when it’s produced its first set of true leaves, before administering nutrients. This is a clear indicator that the plant is ready to receive inputs to ramp up growth.

Of course, it goes without saying that smaller plants won't need a huge amount of nutrients, so keep this in mind when starting your schedule, and adjust accordingly as your plants develop. In other words, start light, diluting the fertiliser while the plants are young, and then increase as they begin to flourish.

How to fertilise hot pepper plants

Now that we've got the basics covered, we can begin to offer some practical advice on how to fertilise your pepper plants.

Application: liquid vs granular fertiliser

Pepper growers can administer nutrients either by adding them to the soil or spraying the leaves. The way you apply your fertiliser will largely depend on the specific product type and contents.

Liquid fertilisers are suitable for both of these applications. They first need to be diluted, and then you can water them into the soil as usual, or you can spray the leaves. A simple spray bottle is often enough to achieve this. For example, some pepper growers like to spray their plants with a phosphorus-rich solution to boost growth. Just make sure never to spray in excess, as this will do more harm than good.

Misting Bottle (Zamnesia)

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Granular fertiliser, on the other hand, is made to be applied to the soil to be taken up by the roots. These formulas are often slow-release in nature, so you may find that one scoopful (for example) is enough to feed your plant over the course of several weeks. Be sure to keep up a regular watering and maintenance routine, and you'll see your plant flourishing with minimal effort.

Should you give nutrients to pepper seedlings?

While many opt to provide nutrients to seedlings, some allow them to first grow of their own accord, only administering fertiliser once they’ve been transplanted into a bigger pot. If you do choose to feed your young plants, be extremely careful with dosing, even halving the product manufacturer’s dose recommendations if necessary.

Hot pepper fertilising tips

While we've hinted at a few pitfalls you can encounter when fertilising your pepper plants, let’s break things down a little further. Here are some common issues and solutions surrounding pepper plant feeding.

Nutrient burn

Nutrient burn occurs when pepper plants are exposed to excess nutrients. This condition can be identified by observing the colour of the leaves. If you notice brown spots appearing, this could be a likely warning that your plant is experiencing nute burn. The brown spots themselves are a result of the nutrients travelling through the plant and having nowhere else to go, causing discolouration and burning. However, marks and spots on the leaves can also be an indication of diseases or pests, so be sure to rule those out before looking to amend your fertiliser schedule.

If it turns out that it is nutrient burn, you can easily dial back the amount of fertiliser, and that should be enough for the plant to correct itself. If not, continue with the next point.

Flushing

As mentioned, overuse of fertiliser will only damage your plants, and while dialling back the amount should remedy this, a more thorough method is known as flushing. This is achieved by watering your pepper plants without any additional nutrients—just plain old water. By drenching the substrate until water begins to drain out of the bottom of the container, the remaining nutrients and salts in the substrate will be rinsed out. This essentially “resets” the soil and allows you to administer nutrients again, knowing there isn’t a buildup lurking in the substrate.

While this is the perfect solution for those growing in containers, indoors or outdoors, those growing directly in the ground can flush by administering pure water for a couple weeks before starting up with nutrients again.

Nutrient lockout

Another issue growers tend to encounter is incorrect pH. When it comes to your growing medium, chilli pepper plants tend to enjoy a pH level of 5.8–6.8. Any higher or lower, and the plant can struggle to absorb the nutrients provided. This phenomenon, known as nutrient lockout, is just as bad as giving your plants no nutrients at all! So it doesn't matter if you've picked up the finest fertiliser filled with all the nourishment your plant needs; if the pH level in the soil is not correct, it won't make a difference.

Check soil pH

So before anything, even before germinating your pepper seeds, check the pH level of your substrate to ensure you're on the right track. This can easily be performed using a pH meter. When it comes time to administer nutrients, make sure your solution is within the ideal pH window, and then measure the soil after feeding to ensure everything looks good.

Keep a close eye on your hot pepper plants

Keeping a regular maintenance schedule is paramount to producing superior chillies. As we've discussed, many symptoms of fertiliser-related issues manifest in the leaves. So be sure to pay attention to any changes in your plants, and you should be just fine.

Of course, dialling in the perfect feeding regimen comes with practice, so if you're new to the process of cultivating chilli pepper plants, don't worry. If you give your plants too much fertiliser, or too little, simply rectify the issue to the best of your ability, learn from your mistakes, and next time you'll have even healthier and better-performing plants!

Adam Parsons

Professional cannabis journalist, copywriter, and author Adam Parsons is a long-time staff member of Zamnesia. Tasked with covering a wide range of topics from CBD to psychedelics and everything in between, Adam creates blog posts, guides, and explores an ever-growing range of products.

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