Urban Plant Oasis

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Why Fertilize?

A couple times in the past few months, I've had a person look me dead in the eyes and say something along the lines of "Oh, I didn't know I needed to fertilize my plants." Welp, its true folks. I wanted to outline some basic fertilizing 101 facts for those of you getting started in the plant world. 

Why Fertilize?

Plants need to be fertilized because most soil doesn't actually provide the essential nutrients required for growth. Even if you are lucky enough to start with great garden soil, as your plants grow, they absorb those nutrients and leave the soil less fertile. 

There are six primary nutrients that plants require. Plants get the first three—carbon, hydrogen and oxygen—from air and water. Sweet. Easy, right? The other three are nitrogen, phosphorus and potassium.

Nitrogen helps plants make the proteins they need to produce new tissues. In nature, nitrogen is often in short supply so plants have evolved to take up as much nitrogen as possible, even if it means not taking up other necessary elements. If too much nitrogen is available, the plant may grow abundant foliage but not produce fruit or flowers. Growth may actually be stunted because the plant isn't absorbing enough of the other elements it needs.

Phosphorus stimulates root growth, helps the plant set buds and flowers, improves vitality and increases seed size. It does this by helping transfer energy from one part of the plant to another. To absorb phosphorus, most plants require a soil pH of 6.5 to 6.8. Organic matter and the activity of soil organisms also increase the availability of phosphorus.

Potassium improves the overall vigor of the plant. It helps the plants make carbohydrates and provides disease resistance. It also helps regulate metabolic activities.

How Often Should You Fertilize?

Well, all plants are different. Some plants require mayyyybe once a year, and other plants require once a month all year long. It really depends on the plant and I highly recommend doing research! Here are a few examples of frequency of fertilizing for plants I have at home.

Monstera Deliciosa… & Most Plants

The Swiss Cheese Plant is a pretty quick growing plant in the summer months, and slows down a bit in the winter (if you live in an area like I do where we experience true winter). This is actually the case for a lot of plants! Some examples are the Bird of Paradise, Croton, Ficus “Rubber Tree”, etc.

During the warmer and sunnier months of the year (April - September) it’s best to fertilize your Monstera about once a month. During the cooler and cloudier months of the year (October - March) these plants don’t actually need much if any fertilizing. Why? Well because there’s not a lot of sun for your plant to soak up, so it’ll naturally go dormant and slow growth on its own. If it’s not actively trying to grow, fertilizing will be force-feeding it nutrients it cannot intake. This can cause a build-up of unnecessary nutrients that will actually make your plant sicker.

Peace Lily

This plant is a miracle, honestly. It grows very well in low light and actually only needs fertilizing maybe once a year. Seriously. Unlike many house plants, Peace lilies actually don’t go into a dormant stage during the winter. They don’t formally bloom, but they don’t die back either. So while fertilizer isn’t necessary and water needs are reduced somewhat in winter, you don’t need to change their care much throughout the year.

It’s important to watch your Lily for signs: green blooms indicate over-fertilization. Since your Peace Lily has the potential to last for years, you can experiment. Green blooms just mean that you can cut the fertilizer dose in half the following growing season.


And there we are! For questions on fertilizing shoot me a direct message! Always happy to chat plants. :)