When and How to Fertilize Anthurium Plants (Essential Guide)

If you want to add a tropical look and feel to any room, the Anthurium plant makes it easy. With their symbolic, thick, glossy leaves and dramatic, colorful spathes, these lovely plants are a perfect choice for your indoor garden offering a host of uses and benefits. When grown under optimal conditions, they’re also easy to care for, and that means using the right amount and type of fertilizer at the right times. Read on to learn when and how to fertilize your Anthurium.

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Fertilizing Anthurium Plants – The Essentials

Fertilize your Anthurium plants only during the growing season, or the spring and summer. Every four to six weeks, apply a fertilizer that’s high in phosphorous, such as a 10:30:20 ratio. Dilute the fertilizer to one-quarter strength before applying. Over-fertilizing is worse than under-fertilizing, so feed your Anthurium sparingly.

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The Role of Fertilizing in Anthurium Plant Health and Growth

Like all plants, Anthuriums need nutrients to survive. When Anthuriums grow in a natural, outdoor habitat, they get the minerals and nutrients they need from decomposing plant and animal matter found in the soil, known as biomass. But when Anthurium plants are grown inside, they don’t have access to biomass. You must provide the nutrients the plants need, and fertilizer offers an easy way to do it.

All types of anthurium plants (including rarer species like the Anthurium crystallinum) grow best when they receive specific types, amounts, and combinations of nutrients. Plus, the nutrients must be applied at the right time to be effective, allowing the plant to grow strong and healthy which in turn helps with the likes of pest and disease control.

One of the easiest ways to feed your Anthurium is by using commercially available fertilizers. These contain the nutrients plants require to grow and thrive, such as the three primary macronutrients, nitrogen (N), phosphorous (P), and potassium (K). Plants also require secondary macronutrients, like calcium (Ca), magnesium (Mg), and sulfur (S).

Plants also require smaller amounts of micronutrients, such as:

• Boron (B)
• Chlorine (Cl)
• Copper (Cu)
• Iron (Fe)
• Manganese (Mn)
• Molybdenum (Mo)
• Nickel (Ni)
• Zinc (Zn)

Each type of plant grows best when provided with a specific mix of macro- and micro-nutrients. Commercially prepared fertilizers contain varying amounts of these nutrients. Manufacturers are required to provide a nutrient analysis on the fertilizer packaging. Luckily, these are standardized to make them easy to read.

Primary Macronutrients for Anthurium Plants

First, you’ll see a list of primary macronutrients listed as a ratio of N-P-K. For instance, the numbers 10-30-20 meant that the fertilizer contains 10 percent N (nitrogen) to 30 percent part P (phosphorous) to 20 percent K (potassium).

Finding a ratio that meets your plant’s specific nutritional needs is key. You’ll usually see these common types of fertilizer:

• Complete fertilizer, which contains all primary macronutrients N, P, and K
• Granular or dry fertilizer, to be mixed in or sprinkled onto the anthurium soil mix.
• Soluble or quick-release fertilizer may be a liquid or powder that’s combined with water
• Slow-release fertilizer is available as spikes, tabs or bits that are added to soil and release nutrients slowly

Many houseplants require more fertilizer during the growing season and less (or no) fertilizer during the winter. For Anthurium, this means feeding only in the spring and summer months.

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Signs Your Anthurium Plant is Lacking Nutrients and Needs Feeding

In their natural habitat — the tropical rain forest — Anthurium plants are often epiphytic. This means they grow on other plants, trees, and structures. This also means they don’t need a lot of nutrients to thrive.

Anthurium plants don’t need feeding very often, as they grow slowly. How do you know if your Anthurium plant needs fertilizer?

Signs your Anthurium may need fertilizer include faded foliage or a drooping plant in general. This can also be a response to too-high temperatures, so check that first before adding fertilizer. When your Anthurium is sitting in bright, direct sun or near a heat source, pale leaves may result. If this isn’t the case, you may try applying a highly diluted, balanced fertilizer.

If your Anthurium isn’t blooming the way you’d like it to, applying fertilizer may help. Choose a phosphorus-rich mixture to encourage your plant to produce colorful spathes; just dilute it first.

When and How Often Should You Fertilize an Anthurium Plant?

Fertilize your Anthurium plant only during its active growing season or during the spring and summer months (also the best time for pruning and repotting anthuriums if needed). Apply fertilizer about every four to six weeks during this time. Do not fertilize during the rest of the year (and avoid fertilizing recently propagated anthurium plants until they’ve had a chance to root).

Some recommend applying very diluted fertilizer — down to one-tenth strength — more frequently, such as every other week, to encourage more blooms. If you choose this method, only apply fertilizer during the spring and summer.

The Best Fertilizer for Anthurium Plants

Anthurium plants thrive and bloom when provided with high phosphorous fertilizer. This means a larger middle number when looking at macronutrient ratios on the fertilizer packaging. For instance, fertilizer with a ratio of 10:30:20 has a relatively high phosphorous content.

No matter which ratio you choose, dilute it to about one-quarter strength for use every four to six weeks (and to about one-tenth strength if used more often to encourage blooms).

A soluble or liquid fertilizer is a good choice, as these are easy to dilute. It’s harder to control amounts when using granular or slow-release fertilizers.

Commercially available products appropriate for use on Anthurium plants include:

• E-Z Gro Blossom Booster 10-30-20
• Jack’s Professional 10-30-20 Blossom Booster
• Jack’s Orchid Bloom Booster 3-9-6
• Peter’s 10-30-20

(Editors Note: Petal Republic participates in partnership programs with Amazon and other merchants to help connect readers with relevant products and services we may recommend).

Try boiling fish or chicken bones if you want to make a homemade formula. Let the boiled bones dry, then pulverize them in a powerful blender or cut them up finely. Then work the bone meal into the soil to up the phosphorous level. 

How to Apply Fertilizer

Before you apply fertilizer to your Anthurium plant, be sure to dilute it to about one-quarter strength. If you’re doing more frequent feedings, dilute the fertilizer to about one-tenth strength.

The day before you feed, water your plant. The next day, gently pour the diluted fertilizer around the plant base. Pour slowly until excess drains from the pot’s drainage holes.

It’s worth noting that Anthurium plants are considered somewhat toxic to humans and pets so it’s prudent to wear a pair of gloves when handling these plants.

Key Considerations to be Aware of When Fertilizing Anthuriums

As a general rule, over-fertilizing an Anthurium has more potential to harm the plant than does under-fertilizing. Why? Because commercially prepared fertilizers contain soluble salts. Over time, these can build up in the soil. This makes it difficult for plants to take up the moisture they need.

Signs of an overfed Anthurium may look a lot like an under-watered Anthurium or plants that have received too much light exposure. Yellowing or wilted leaves, scorched foliage, and withered stems may all indicate over-fertilization. Too much fertilizer can even lead to root rot.

If you suspect over-fertilization, flush the soil. Place the plant pot in the sink or tub, where it can drain. Slowly pour filtered or distilled clean into the pot, allowing excess to flow out the bottom of the container.

Do this about four times or about four pots worth of water. Let the plant continue to drain for a few hours before returning it to its usual spot.

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Fertilizing Anthurium Plants FAQs:

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The Final Word on Fertilizing Anthuriums

Anthurium plants add a tropical flair to any room, thanks to glossy foliage and colorful spathes. Fertilizing with a phosphorus-rich, highly diluted blend a few times during the growing season will help your Anthurium plants thrive.

If you’re looking for your next anthurium plant, see our in-depth guide to the best plants shops delivering anthuriums nationwide.

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