Most people bring watermelon peperomia plants home due to their vibrantly striped, green leaves. I know that’s what hooked me on this plant! If you want to keep these leaves looking lush, learn how to properly fertilize them. To help you out, I’ll share all I’ve learned about when and how to fertilize watermelon peperomia.
Why Plants Need Nutrients
Although plants use energy from the sun to produce carbohydrates ( that process is known as photosynthesis, in case you forgot), this doesn’t provide them with nutrients like nitrogen, potassium, and phosphorus. Plants absorb these nutrients from the soil and use them to complete essential plant processes.
If plants don’t have access to the nutrients they need, they can’t properly build new cells, fight common watermelon peperomia diseases, and move water throughout their tissues. Plants need 16 different nutrients to thrive, and each one plays a different role in the plant.
Plants need the highest amount of nitrogen, potassium, and phosphorus. Therefore, people refer to these three as macronutrients. Plants require smaller amounts of the three secondary nutrients: calcium, sulfur, and magnesium. People refer to the remaining nutrients as micronutrients since plants only need small doses.
Choosing the Proper Fertilizer for Watermelon Peperomia
When it comes to choosing a fertilizer for your watermelon peperomia, consider the nutrient ratio, fertilizer strength, and formulation.
Understanding the NPK Ratio
When people ask me about fertilizers, I tell them one of the most important aspects to consider is the NPK ratio. This number refers to the amount of nitrogen, phosphorus, and potassium in the fertilizer, and you can find it on the fertilizer label.
The NPK ratio is useful for two reasons. First, it explains the ratio of one nutrient to the next. While vegetative plants prefer fertilizers with balanced NPK ratios, flowering plants benefit from fertilizers with higher amounts of phosphorus and potassium than nitrogen.
The NPK ratio also shows you the strength of the fertilizer. While a 1-1-1 fertilizer and a 20-20-20 fertilizer have the same nutrient ratios, one is much stronger than the other,
So, what NPK ratio is best for watermelon peperomia? A 1-1-1 ratio will provide the necessary nutrients without causing fertilizer burn. You can also dilute a 2-2-2 or 3-3-3 fertilizer with water.
Liquid vs Granular
Both liquid and granular fertilizers provide nutrients, but I prefer liquid options for houseplants. They’re ready to apply and easy to dilute in water.
Signs Your Watermelon Peperomia Lacks Nutrients
Since watermelon peperomia plants don’t require many nutrients, they often show subtle signs of nutrient deficiencies. At first, your plant may look healthy but fail to put on new growth. While this may be due to a lack of light or improper watermelon peperomia temperature range, it can also indicate the plant needs more nutrients.
As nutrient deficiencies increase, watermelon peperomia plants may develop yellow or faded leaves.
When and How to Fertilize Your Watermelon Peperomia
Many people say you should fertilize your watermelon peperomia about once a month in the spring through fall and stop fertilizing in the winter. This will keep the plants happy since they’re slow-growers that don’t require many nutrients.
However, this isn’t necessarily the best advice.
While researching how to properly care for my watermelon peperomia, I saw someone mention they fertilized their plant each time they watered it. This advice went against the status quo, but their plant’s health didn’t lie. The hundreds of lush leaves covering the plant quickly gave me plant-envy.
I decided to combine this advice with the standard advice. I fertilized my plant each time I watered it in the spring through early fall and stopped fertilizing when October arrived. I simply squirted some fertilizer on the soil and then watered well. You can also mix the fertilizer with water and then apply it.
And this method worked great! My plant put on new growth without showing any signs of overfertilization.
It’s important to note that I applied just a splash of fertilizer (about a teaspoon) each time I watered. And I watered my plant about once every two weeks, which meant I fertilized it twice a month.
Signs of Overfertilization
Yes, it is possible to apply too much fertilizer! And applying too much fertilizer can be more dangerous than adding too little!
Some indications you’ve applied too much fertilizer include brown leaf tips, white crust on the soil surface, and dropping leaves. If you notice these symptoms, water your plant well and decrease fertilization.
Regularly fertilizing your watermelon peperomia with a balanced, low-dose fertilizer will help keep it happy. Remember to choose a product with a low NPK ratio and apply it a few times a month.
Briana holds a B.S. in Plant Sciences from Penn State University. She manages a small market garden where she grows vegetables and herbs. She also enjoys growing flowers and houseplants at home.