Philodendron Melinonii Care Guide & Factfile: Made Simple!

Philodendron Melinonii is an evergreen, large-leafed, non-vining member of the Aroideana family. Quite easy to care for, this dark green philodendron makes an impressive houseplant but can equally thrive outdoors in the right conditions.

While keeping this beautiful plant alive is relatively easy, there are a few pitfalls you should know about.

Below, we’ll go over proper Philodendron Melinonii care and explain how to keep this beautiful plant alive whether it’s in a pot or in the ground outside.

What is Philodendron Melinonii?

Pronunciation: Phil-oh-den-dron Mel-i-no-nee-eye

Appearance: Defined by its large, dark green foliage and clearly defined veins, the P. Melinonii commands attention. The leaves are oblong-triangular and can easily reach 19 inches long.

These are supported by a thick petiole which can vary in color from coppery red to pale green.

The underside tends to be a little lighter than the top and allows a little light to get through despite the thickness of the leaf. The base of the plant is fibrous and brown.

In the wild, as an epiphyte, you will find P. Melinonii growing like a crown on top of trees. These rosettes are typically 6ft across with short internodes, giving them a bushy appearance.

Origin: Philodendron Melinonii originates from the rainforests of Central and South America. Most notably:

  • Northern Brazil
  • Venezuela
  • Suriname
  • French Guiana

Rarity: The plant is relatively common in its native environments, especially in the northern part of South America. In the region of Manaus in Brazile, P. Melinonii is considered the dominant epiphytic species.

Despite this, the plant is still quite rare within private collections.

Other names: In older or more scientific publications, you may see the plant’s name accompanied by the term “Brongn ex Regel.”

Caring for your Philodendron Melinonii

P. Melinonii is relatively hardy and will happily thrive indoors in a large enough pot. It can also be grown outdoors if you enjoy a warm climate where the temperature does not dip below 55oF / 13oC.

  • Light: bright, mostly indirect light
  • Soil: well-draining
  • Watering: weekly
  • Humidity: 65-80%
  • Temperature: 18o-30oC (65o-86oF)
  • Fertilizer: 4-6 weeks

1. Light

Like most Philodendrons, P. Melinonii does best with plenty of bright indirect light.

Growing above the canopy of the rainforest, these leaves can tolerate 2-3 hours of direct sunlight. However, over time this may alter their color.

You will want to ensure light levels remain above 50 FC with the optimal levels for good growth sitting between 200 – 400 FC.

Too much light: wilted, yellow leaves

Too little light: leggy growth, stunted leaves

2. Soil

Philodendrons grow best in peat-based soil with adequate drainage. A free-draining, looser substrate allows the soil to retain the right amount of water while also incorporating enough oxygen.

Peat soil is great for philodendrons because of its high organic matter. The benefits for philodendrons include:

  • Ideal acidity (pH 6-6.5)
  • Loose enough for root growth
  • Allows oxygenation

While you can buy pre-made bags of Aroid soil mix, it’s quite easy to make your own. All you need is to create a mixture of the following:

  • Coconut coir (60%)
  • Perlite (30%)
  • Orchid bark (10%)

This DIY peat soil mixture can be scaled up or down to your requirements provided the ratios are kept the same.

3. Water

Native to the hot and humid climate of South America’s rainforests, P. Melinonii likes its soil to be moist. If the soil is left to become dry you will find the leaves will droop and go brown in color.

Overwatering will result in similarly droopy leaves but they will turn yellow.

You will want to give your Philodendron Melinonii a good soak until water trickles out the drainage holes in the bottom of its container.

Only water when the top 50-70% of soil has gone dry. In most indoor environments, this will mean you will need to water your P. Melinonii about once a week.

In between, you will want to spray the leaves of the plant once or twice a week to mimic the humidity of the rainforest.

In order not to “shock” the plant, ‌let tap water reach room temperature before pouring it onto the soil.

As with most plants, rainwater is best, as tap water can contain chlorine. If you can’t get hold of any rainwater, simply let the chlorine evaporate out the tap water overnight.

4. Temperature

Philodendron Melinonii thrives best in conditions that are similar to its natural tropical climate. This can be replicated indoors by keeping temperatures between 18-30oC.

At a minimum, P. Melinonii should not be exposed to temperatures below 13o-15oC (55o-59oF). Prolonged exposure to such temperatures will result in a stunted or unhealthy plant.

5. Humidity

P. Melinonii needs a constant humidity level between 65-80% to grow best.

This can be achieved through misting twice a week, or more if you’re in a particularly dry environment.

You can also introduce moisture to the air surrounding the plant by:

  1. Investing in a humidifier
  2. Place near a wetroom or bathroom
  3. Leave open containers of water near the plant
  4. Place near other plants

6. Fertilizer

In the spring and summer months, proper Philodendron Melinonii care means fertilizing once a month. In the fall and winter, this can be extended to every six to eight weeks.

Signs that your plant needs an additional boost of macronutrients (such as magnesium and calcium) are:

  • Slow growth
  • Small leaf size
  • Pale leaves

The best kind of fertilizer for philodendrons‌ is one with an NPK (nitrogen, phosphorus, potassium) ratio of 20:20:20. This is a common ratio and can be found quite easily in commercial mixes.

Philodendron Melinonii Growth – What to Expect?

While there are bigger varieties in the Aroideana family, P. Melinonii is still a relatively large plant.

Store-bought Philodendrons Melinonii will typically come around 20 inches high with leaves around 8 inches long. These can easily reach 6-8 feet in diameter in a large enough container in the right conditions.

As a house plant, you can expect P. Melinonii to gain more height than width. With strong petiole, the plant can reach heights of 8 feet and more.

The plant doesn’t really “flower” but does produce an ornate spathe. A single plant may produce 2 to 3 of these blooms a year, with most philodendrons “flowering” May through to July.

How to Propagate a Philodendron Melinonii

The best way to propagate a Philodendron Melinonii is to take some stem cuttings from a healthy plant:

Step 1: Cut a 3-4 inch long branch with foliage and exposed aerial roots.

Step 2: Remove the foliage from the bottom of the cutting, leaving the roots attached.

Step 3: Push this cutting 1-2 inches into moist soil and keep it in a shady location.

Step 4: Within a week, the roots should develop and the cutting will be ready for potting.

The same process can also be done with water instead of soil. Just be sure to change the water every few days.

Plant Toxicity

Human: Toxic. Mild-moderate.

Animals: Toxic. Mild-moderate.

As with all philodendrons, the Melinonii contains insoluble calcium oxalate crystals. Many plants in the Araceae family contain this irritant, which can cause some unpleasant side effects if ingested. The plant is therefore considered to have a mild-moderate toxicity level.

Chewing or biting a philodendron will result in these calcium oxalate crystals irritating the mouth and throat. In rare cases, this can cause swelling of the airway and make it difficult to breathe.

The sap has been known to cause skin and eye irritation too and should also be treated as an irritant.

Common Pests, Diseases, and Other Issues

The most common issues you will face with P. Melinonii are:

Bacterial leaf spot

The most common disease is bacterial leaf spot disease. This can be identified by brown spots with yellow halos or dark spots with black outer rings forming on the plant’s leaves. The spots may have irregular shapes and spread and the leaves may become brittle or alter in color.

Leaf spot can be managed by removing the offending leaves and removing dead ones. The overall stress on the plant is quite mild and can still grow quite healthily this way providing there are enough leaves for photosynthesis.

Bacterial Blight

Identifiable by rapidly expanding dark green spots on the leaves and petioles, causing a wet rotting smell.

Also a bacterial problem, blight can be prevented by only watering the soil and not over-misting the leaves.

Magnesium Deficiency

Lack of magnesium can be spotted by v-shaped yellow areas forming on your plant’s leaves.

To remedy this, apply one teaspoon of magnesium sulfate to a gallon of water and use that to water your plant as normal.

Tip curl

If the tips of your plant curl downwards and the roots look dead, you may have over-fertilized your plant.

If your plant exhibits these symptoms, you should reduce the rate at which you fertilize your soil and repot if necessary.

You can help prevent the most common problems by following these general rules:

  • Only water the soil, not the leaves. This ensures bacteria do not have a chance to form.
  • Don’t over-mist. Excess moisture is a catalyst for bacterial growth.
  • Don’t over-fertilize.
  • Ensure the plant has adequate air. This includes the soil too which can be aerated with chopsticks or a similar instrument.

Philodendron Melinonii Care Guide FAQ

Q. Philodendron Melinonii vs Philodendron Imperial Green – What’s the Difference?

Philodendron Melinonii is an epiphyte, meaning it grows on another plant. In this case, on the tops of trees in the rainforest natively.

Philodendron Imperial Green, on the other hand, will typically be found in the wild growing on the side of rocky outcrops and near riverbanks.

The Imperial Green will typically be more vertical than the Melinonii variety.

Q. Why does my Philodendron Melinonii have pale leaves?

These plants love bright spots and can tolerate a couple of hours of direct sun a day. If your plant’s leaves are on the paler side, it could be a sign it’s not getting enough light. Try a brighter area.

Q. The leaves on my P. Melinonii are curling. What am I doing wrong?

As with most Philodendrons, this is a classic sign of under-watering and inadequate humidity levels. If your plant’s leaf tips are curling and brown edges are forming, you need to water and mist more regularly.

The amount should be upped slowly, however, to ensure you don’t over-water the plant.

Q. My P. Melinonii has lost some leaves. Is it dying?

Some leaf loss is normal. Like all plants, older leaves will eventually drop off naturally.

If you find your plant is losing a lot of leaves, it could be a sign that the plant is in shock. This could be caused by sudden temperature or light changes if the plant has been moved.

Your plant may need time to adjust and if the symptoms persist, the spot may not be suitable.

photo of Charlotte Bailey founder of Oh So Garden

Author

Charlotte Bailey

Charlotte is a Qualified Royal Horticultural Society Horticulturist, plant conservationist, and founder of Oh So Garden. Armed with a background in Plant Science (BSc Hons, MSc) and 5 years of hands-on experience in the field, her in-depth guides are read by over 100,000 people every month.

For her work, she's been awarded the title of Yale Young Global Scholar, and been featured as a garden and houseplant expert across major networks and national publications such as Homes and Garden, Best Life, Gardeningetc, Today.com, BHG, Real Homes, and Country Living. You can find her on Linkedin.

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