Philodendron Black Cardinal Care – Best Kept Secrets!

The philodendron black cardinal has long been collected for its prized for its rich dark chocolate foliage that eventually hardens off to an almost jet black color. The large oval shaped leaves first unfurl as a lighter bronze or burgundy red before transforming into their signature colors. In this guide, I’ll cover everything you need to know about philodendron black cardinal care, so you can keep your new plant happy and healthy.

Why is My Philodendron Black Cardinal Dying? 

  • ‘No matter what I do, its leaves wilt’
  • ‘Its leaves grow well for a little bit and then just yellow and drop off’
  • ‘I just can’t get it to grow like my other philodendrons’

If this sounds like you, there are 3 main culprits I’d take a look at: 1) the size of your pot, 2) your watering method & frequency, 3) the amount of light its getting.

From my experience, philodendron black cardinals have similar care requirements to the philodendron prince of orange and dark lord, and when they’re dying, it’s usually because they’re placed in a much bigger pot than needed which causes the mix to either become too wet or too dry.

Or, they’re being given way too much water for the light they’re receiving. Check out the care sections below to see if there’s some little tweaks you can make. Sometimes, small changes are all that’s needed!

Philodendron Black Cardinal Care

Soil

The philodendron black cardinal thrives in a well-draining, airy and rich organic potting mix. As a general rule of thumb, this should contain approximately 40% organic material (coco coir, peat, worm castings etc), 40% inorganic material (pertite, activated charcoal, pumice, vermiculite etc) and 20% orchid bark chips. This supports their epiphytic, or hemi epiphytic nature and allows their roots to do what they do best and attach.

I love and use this mix for my philodendrons:

  • 40% coco coir
  • 20% orchid bark
  • 10% perlite
  • 10% worm castings
  • 10% pumice
  • 10% activated charcoal

The key to creating the perfect potting mix for the philodendron black cardinal is to make sure it has both moisture retaining elements as well as moisture draining elements in good balance.

The mix above has a 50% organic to 30% inorganic ratio.

If, overtime, you find the mix dries out too quickly, you can add more moisture retaining elements such as coco coir or worm castings as I did above. 

What Each Element Does

  • Coco coir (replaces soil) – holds moisture whilst also being well-draining, very easy growing medium to work with
  • Perlite – pressed volcanic rock, porous structure, aids in drainage and holds key nutrients from fertilizer
  • Orchid Bark – an epiphyte’s FAVORITE soil amendment, it becomes a hotspot for positive microbes, root attachment, plus chunkiness allows for extra drainage
  • Worm castings – organic fertilizer (literally worm poo), has a full nutrient palette and holds moisture
  • Activated charcoal – prevents build up of soil impurities, stops mould and neutralizes pH of soil
  • Pumice – another drainage element (can be removed if potting mix becomes too dry)

Light

The philodendron black cardinal grows extremely well when given lots of bright, indirect light. Under brighter light, you’ll see faster growth and that signature burgundy, jet black coloring become bolder. Despite what many guides tell you, keeping it somewhere that receives 1-3 hours of cool direct morning sun or late evening sun can do wonders for its foliage growth. This type of light really maximises its darker coloring. Leaves scorching or bleaching only appear when the black cardinal is placed in direct sun for hours on end, right throughout the afternoon when light is more intense.

How to Tell if Your Plant is Getting Enough Bright, Indirect Light

Bright, indirect light is much brighter than you probably think! As light is hard to measure and what seems bright to me might not to you, I use a light meter to really understand what’s going on. Light meters measure overall light intensity in foot candles (FC) and can be picked up for less than $50.

How Much Light Does my Black Cardinal Need?

Research shows that the black cardinal needs at least 200FC for maintenance (bare minimum). For good growth (what you’re probably looking for), anywhere between 400-600FC is ideal. 

FYI, black cardinals are grown in 1500-2500FC in nurseries and other commercial outlets under a 20-40% shade cloth. This just goes to show how vague the term ‘bright, indirect light’ really is!

Watering

The philodendron burle marx loves evenly moist, well drained soil. The key here is well drained and not waterlogged or boggy. An airy potting mix (see above) goes a long way in helping wick away any excess water.

Friendly Tip: Overwatering isn’t caused by the amount of water you use, but the frequency of waterings and the soil’s aeration quality.

How Often Should I Water?

Instead of following a strict watering schedule e.g. once a week, get into the habit of checking if your plant really needs water.

Plants in higher light conditions, in warmer temperatures, will need much more water than a plant kept in lower light, in cooler temperatures. Light and temperature changes year round, with the seasons. You’ll need to water more in summer and spring than in autumn and winter for this reason.

How to Tell When Your Philodendron Black Cardinal Needs Water

There are 2 methods you can use: 1) bamboo stick test and 2) knuckle test

What I do and recommend is to use a bamboo chopstick, dig it into the soil, a good few inches deep, and observe what you notice. 

Wet soil will cling to the chopstick and possibly make the stick a darker shade

Moist soil will be soft in texture (you’ll easily be able to push the stick through)

Dry soil will be tough, brittle and compacted and won’t change the color of the stick

Or, you can use the more common knuckle test. Stick your finger into the potting mix. If it is moist at the first or second knuckle, you can hold back on watering. If it is dry, your plant needs a good drink.

Always make sure to check the color of the soil and texture too. If the mix is really dark, it’s likely it doesn’t need any more water. If the soil is light, hard and compacted, it’s become super dry.

How to Water Your Black Cardinal (The Right Way)

Make sure you give your plant just enough water so that small trickles drain through the drainage holes. It’s better to give it a good watering infrequently than give it small amounts of water frequently. Water around the entire pot too, not just in one spot. This helps to prevent rot and bacterial infections from starting.

Humidity

Being tropical plants, it should come at no surprise the black cardinal philodendron loves high humidity (think 80% or higher). You’ll likely be rewarded with bigger leaves because of it. They can cope with lower household humidity levels e.g. 40-50%, but as expected you’ll see smaller growth overall (but not so small that you wouldn’t want to grow it). Humidity is an important care factor, but it’s nowhere near as essential as getting the light levels or watering frequency right for example. 

How to Increase Humidity in the Drier, Winter Months

There are only 2 real ways to increase humidity so that your plants benefit. 

  • Invest in a small humidifier
  • Group plants together to create a mini humidity sharing biome in your home.
Myth Buster: Misting drastically helps to increase humidity for plants.

A. Complete myth - it’s more therapeutic than beneficial. Misting creates tiny droplets of moisture which linger around the plant for 30-60 seconds before completely dispersing around the room. 

It doesn’t do much to actually help your plant, and if overdone, can cause nasty bacterial and fungal infections thanks to indoor air having little to no natural circulation.

Temperature

The philodendron black cardinal is a true warmth lover. The warmer, the more likely you are to see bigger, faster growth, if all other care conditions are met. The ideal growth range lands between a cozy 68°F to 78°F (20°C to 26°C), though they can handle as low as 59°F (15°C). Anything less than 54°F (12°C) and you’re likely to see severely stunted growth, wilting and a loss of that stunning jet black coloring.

Fertilizer

Unlike plants in the wild, houseplants have no way of getting nutrients once they’ve used up all the nutrients in their potting mix. This is why houseplants need regular fertilizing with a nutrient rich solution.

Best Fertilizer for Philodendron Black Cardinal

There are lots of options available to you on the market, including an all-purpose houseplant fertilizer, but I love and use dyna gro (7-9-5 NPK). It contains all 16 essential macro and micronutrients your plant needs to thrive. It’s also low in heavy nitrogen salts (which can cause dreaded root burn).

I used to use osmocote but they’ve since changed the formula to include thousands of microplastics – I don’t recommend them anymore.

If you already have a favorite, by all means, go ahead and use that.

How Often to Fertilize Your Philodendron Black Cardinal

I used to fertilize my houseplants once a month like many nursery guides say to do but it just seemed off to me. It’s not how plants feed naturally – they receive a steady stream of nutrients over time rather than one big dose a month. Now, I fertilize my plants every time they get watered. You’ll see this referred to as maintenance feeding on some fertilizer bottles.

How to Create a Diluted Fertilizer Mix

I dilute 1/4 teaspoon of dyna gro with 1 gallon of water (4.5 litres) and water my plant with this solution every time in spring and summer (when the plant is showing signs of needing to be watered).

I cut back both on waterings and feedings in autumn, and stop fertilizing completely in the winter months to prevent oversaturation during the more dormant part of their growth cycle.

Many people think plants just stop growing in winter - but there’s a little more behind it. 

When the days are shorter, there’s less light and the temperature is much lower. This results in little to no growth. If you could keep the optimal growing conditions all year round, your plant would continue to grow well, all year round.

Growth – What Can I Expect?

The philodendron black cardinal is a compact, self heading plant meaning that it can hold its own weight as it grows upright. Under optimal conditions, it will grow up to 1m (3 feet) in height and up to 2 feet in width. Mature leaves can grow to a staggering 30cm (1 foot) in length and 20cm (0.6 feet) wide. It’s very similar in shape and size to a philodendron rojo congo and imperial gold. 

Pruning – Should I Prune This Plant?

A self heading variety, the philodendron black cardinal generally doesn’t need much pruning. The only time I recommend pruning it is when you have damaged or diseased leaves.

Repotting

You might have read that philodendrons prefer to be root bound for long periods of time, but this isn’t exactly true. It can tolerate being root bound, but it’s always best practice to move it to a slightly bigger pot as soon as its roots start to curl around the base of the potting mix to help with drainage.

Signs your plant needs repotting includes:

  • Roots are starting to show through drainage holes
  • Your plant is visibly root bound
  • Growth is stagnant
  • Roots are shooting through the top of the mix
  • Potting mix isn’t draining as well as it used to

Friendly Tip: If you’ve just bought your plant from a nursery or Etsy seller, it’s likely it needs repotting fairly soon. Nurseries resell their plants when they’ve reached max growing capacity in that container.

When repotting your philodendron black cardinal, keep these things in mind:

  • Choose a pot that has drainage holes
  • Only select a pot that is 1-2 inches inches bigger than the last (no more).
  • Fill with a high quality, loose, well draining potting mix 

How to Propagate a Philodendron Black Cardinal

This plant isn’t the easiest to propagate. Self heading varieties such as this one are generally grown by tissue culture or seeds by botanists because they have either no visible nodes to take cuttings from, or they’re incredibly short and at the base of the compact plant. You can however cultivate what we call ‘plantelets’ or ‘pups’ which the black cardinal develops as it matures and air layer them.

Propagation is most successful at the beginning or spring or summer. This is one of the MOST important factors to get right when propagating this plant.

Helping Plantelets to Grow

  • Search for little platelets at the base of the plant. Plantelets will grow where old leaves have died off.
  • Wait until it has a visible stem and aerial roots emerging. Placing the philodendron black cardinal in a bright location will help these grow quicker.
  • Air-layer the newly visible stem (see below) to help the aerial roots grow longer and stronger. Air layering typically works in 2-3 weeks.
  • When ready, cut the plantlet off the mother plant and pot it in a well-draining, rich soil mix.
  • Care for your philodendron as usual.

How to Air Layer your Philodendron

  • Look for the small aerial roots shooting out of the plantelet.
  • Take some wet sphagnum moss, and wrap it around the aerial roots.
  • Using a transparent plastic bag or press and seal food wrap, wrap it fully around the moss covered roots (it should now look like a moss ball covered in plastic). Make sure to not catch any leaves in this wrap.
  • If you used a plastic bag, you’ll need a zip tie to secure it in place. Press and seal food wrap should tape itself up pretty well (I’ve always found it much easier!).
  • Leave the top and bottom of the seal open. New roots like to dive downwards and this helps them do so without bunching up.
  • Thoroughly mist the sphagnum moss through the open top in the plastic bag every day. This stops the moss from compacting and drying up. Don’t let the moss ball dry out.
  • Wait 2-3 weeks for new roots to develop.
  • Carefully remove the plastic wrap and some of the moss around your new roots. Check that the roots look healthy (white is a good sign)
  • Cut the plantelet just below the new roots with clean scissors.
  • Pot the plantelet in a moist, rich organic potting mix (see soil section above)

Toxicity – Is the Philodendron Black Cardinal Toxic?

Unfortunately, yes! The philodendron black cardinal is toxic to small children and pets if eaten, including dogs and cats. Its leaves contain high amounts of small oxalate crystals which can cause local swelling in the mouth and gastrointestinal tract.

Help! What’s Wrong with My Plant? – Common Care Problems

Wrinkled Leaves

What you’re seeing is burning. More common than you might think, wrinkled leaves on vining and creeping philodendrons are caused by a phototoxic reaction to liquid fertilizers. When fertilizer is left to dry on leaves, it burns the plant. This is only seen in plants that are watered overhead rather than at the base. Switch to base watering. It won’t de-wrinkle the old leaves, but new growth will come in fine.

Leaves are Pale

Pale leaves are usually a sign of a magnesium or calcium deficiency. A well-balanced and complete fertilizer will solve this problem. This is known as chlorosis type 1.

Dark Patches Appearing on Leaf

Dark patches appearing on leaves can be caused by drastic temperature changes overnight, or at least what your plant considers drastic changes! Philodendrons are not tolerant of cold temperatures and they definitely don’t like frost! Make sure to keep them away from cold, draughty windows too.

Yellowing Leaves

Yellowing leaves can have many causes including too much watering, too little watering, too low temperatures, too high temperatures as well as pests (yikes, that’s a lot!). If you’ve just bought your plant or repotted it, it’s possibly a natural reaction to a change in growing conditions. Your plant could simply be adjusting! Common sense and a little observation is usually all that’s needed to work out what is causing those yellow leaves.

Brown Edges or Leaf Tips

Browning tips are a good sign your plant is chronically underwatered or not watered properly. Every time you water, some water should run through the drainage holes. It’s better to thoroughly water a plant less frequently than to give it small amounts of water frequently. This makes sure the entire mix is evenly moist and not just the top layer.

Stems are Leggy

The burle marx generally has longer, leggier stems than most plants, but leggy stems combined with droopiness are usually caused by a lack of enough bright, indirect light. A plant’s growth is entirely dictated by the amount of light it receives, too little and you’ll see a more wide, open appearance with less foliage. 

Wet, Mushy Patches Appearing on Leaves

Wet mushy patches that look like water soaked lesions are caused by a bacterial infection called erwinia blight disease or erwinia leaf spot. You’ll want to isolate the plant, change the potting mix and give it as much ventilation (moving air) as possible. Unfortunately, bactericides such as copper sulfate have proven to be ineffective in curing the infection. 90% of the time the plant needs to be discarded, sorry!

Mushy, not Water Soaked Lesions on Leaves

If the lesions or spots don’t look mushy or water-soaked, then you’re probably dealing with pseudomonas leaf spot. You should treat this bacterial infection the same way as you would erwinia blight (see above).

FAQ – Commonly Asked Questions

Is the Philodendron Black Cardinal Rare?

No, the philodendron black cardinal isn’t a rare plant. It can be found easily on Etsy as well as some garden centres, most nurseries as well as home depot stores. It’s in wide distribution across Europe, the United States as well as Australia thanks to tissue culture.

Can I start a Black Cardinal from seed? 

Black Cardinals cannot be reproduced from seed. For seeds to work, the plant would need to flower, and indoors, they rarely do. Plus, its unique genetic base means that its ‘variegation’ wouldn’t be reflected in the seed, meaning you wouldn’t see that striking black color. Black cardinals can only be propagated via pup cuttings, division or tissue culture.

2 thoughts on “Philodendron Black Cardinal Care – Best Kept Secrets!”

  1. Thank’s for this comprehensive information! I have added your page to my bookmarks 🙂
    …….an now I hope I can rescue my Black Cardinal Variegata, which I have bought recently. It’s so beautiful, amazing!

    Greetings from Austria

    Reply

Leave a Comment