The Philodendron Black Knight is another rare and not commonly heard of plant. And it is another one I really like, although my daughter disagrees.
I’m not sure but for me the plant reminds of me the kinds of movies Tim Burton makes. Not exactly sure why.
That said, it looks different from other philodendrons, mainly because of its dark colored foliage.
The Philodendron Black Knight has a dark burgundy-green foliage, which makes it look almost black. Although you can really see differences when you look at it outdoors. There it look more black. But inside with the light from the window and fluorescent lighting in the ceiling it is more a very dark purple-black.
As the plant gets older, the leaves also get bigger and darker in color.
In any case, I’ve noticed that because of this (and its name), it often gets confused with other plants
One is the Black Knight or Black Knight succulent. The two are only related by name. That’s because the Black Knight plant is actually a succulent.
So you’ll see the thick leaves. in contrast, this plant is a philodendron, and a climbing one at that.
Then there are other dark or black philodendrons.
Philodendron Black Knight vs. Black Cardinal, vs. Dark Lord vs Majesty
These are your top choices if you want a dark leaved philodendron. But they all look different and are 4 different plants. Here’s how to tell the difference between them
- Philodendron Black Knight – has longer, narrower and sharper heart-shaped looking leaves. This makes it look like an arrowhead. Its long stems also make the plant stand up and curve out so the leaves are away from the center. If you want to keep the leaves tighter, give it a pole to climb. When it clings and climbs the leaves won’t extend and bend as far out. The Black Knight is also a bigger plant.
- Philodendron Black Cardinal – is the most popular of the four. It has large wide leaves and many will argue the prettiest because of its foliage. Its leaves are also more rounded although in a ellipse-like shape. The others are more arrow-like. But the simplest way to tell is that the Black Cardinal is self-heading. It does not climb nor does it have long vines. The other 3 like to climb when give a pole.
- Philodendron Dark Lord – the Dark Lord’s leaves are not as narrow compared to the Black Knight. But like the Black Knight, it will get big with stems growing as long as 2 or more feet up and out. If you look at the edges, there’s significantly more crumpling as well.
- Philodendron Majesty – this one looks the messiest with or without a pole. As it grows more leaves and gets taller, the stems can go in all directions making it look more chaotic. In contrast, the Black Cardinal looks the neatest. The Majesty looks similar to the Black Knight as far as leaves go, although not as pointy at the tip it is still spear shaped. With proper care over the years, this will become the biggest. I’ve seen them between 6 to 7 feet with tons of large leaves. However, it won’t “blow up” sideways which makes it take up less space as a bigger plant compared to the Black Knight and Dark Lord.
Philodendron Black Knight Plant Care
Light Requirements
The Philodendron Black Knight does well in a wide range of lighting conditions. It does not mind low to medium light. But if you want to get the most out of it, bright light is best.
To help it achieve its best colors, positioning it near an east facing window where it receives morning sun. Another option is somewhere in the west where it only gets late afternoon sun (after 4:00 p.m.). Although this is a bit tougher to do since you only want natural light later in the day without that in the mid-afternoon.
The most important thing to remember is to keep it away from direct sun and too much exposure to harsh light. More specifically, the times between 10:00 a.m. to 4:00 p.m., when the sun is the strongest.
Keeping it there will eventually cause its leaves to get sunburn.
In case you notice this damage happening, immediately move your Philodendron Black Knight to somewhere with less light. Also, make sure that the sun’s rays never touch the plant (besides the early morning or late afternoon sun).
I like to check this by looking for any shadow the plant may present during different times of the day. At no time should it have a shadow during the afternoons. It is does, it means the sun is hitting it from the opposite direction of the shadow.
Temperature
With regards to temperature, the Philodendron Black Knight enjoys moderate to warm environments. It is used to tropical conditions and prefers climates between 60 and 80 degrees Fahreneheit.
Like other philodendrons, it can tolerate more heat but not much colder. It does not mind temperatures up to 95 degrees. And will tolerate 100 degree or higher weather.
While mine hasn’t experienced this type of heat (and I also won’t allow it get stay there), I’ve seen the plant happily live indoors and outdoors in Southeast Asian summers which are scorching hot.
The temperature readings when I visit during summers run between 32 to 40 degrees Celsius (which is the unit they use there). That translates to around 90 to 104 degrees Fahrenheit on a daily basis.
And because humidity stays between 60% to 75%, the heat index is actually much higher than what the temperature gauge shows.
However, the plant did not show any problems. That said, they did water it about once every other day.
In any case, as possible, try to avoid extreme heat. And move it to cooler spot once things get to the 90s. And, the hotter the conditions, the more moisture it will need.
On the other hand, cold is something it cannot tolerate.
The Philodendron Black Knight can take temperatures as low as 55 degrees. Avoid anything below 50 degrees as the plant has difficult with conditions this cold. And keep it away from frost and freezing levels.
Humidity
Much like temperature, the plant’s native habitat makes it prefer high humidity. It favors levels between 60% and 70%. But will tolerate 40% and above which makes it easier to take care inside your home.
Depending on how much such it gets and how often you water, it may or may not struggle with relative humidity that’s in the 30s.
However, anything under that it will need some help.
In our old home, I gave the plant weekly showers once humidity dropped to under 35%. So, I can’t really tell what its lowest tolerance really is. I just don’t like taking any risks especially when you’ve spent months and even years taking care for your plants.
Humidity is no longer a problem since we’ve moved. Being close to the water keeps daily humidity at least 55% on average (indoors). I has also gone up to over 80% every now and then.
That said, I highly urge you to pick up a digital hygrometer if you have dry air in your area. That way you’re always aware of what the humidity is. Also, it lets you make mental notes (which you automatically memorize after a while). This lets you immediately know which levels certain plants start showing crispy and dry tips.
I know that’s how I got to know my plants better in my old home. And, since our new home doesn’t require that, I’ve noticed I’ve gotten quite a bit more sloppy (because I can get away with it).
How Often to Water Philodendron Black Knight
If you find often find yourself forgetting to water your plants, the Philodendron Black Knight is something you may want to look at.
It does not mind dryness and does well with little water. In fact, my experiments have taught me that it does not mind letting the soil go dry even until 80%. Again, it could easily take more than that. But, I’m not going further than 80% of the way down.
I feel that the window to water (anywhere after the top inch of soil dries out until 80% of the way down) is already big enough. Even if you often forget, this gives you at least a few days to be late without any consequences.
To check, just stick your finger into the soil and feel until where moisture is. I always make sure to do this before I start watering.
This ensures that you don’t have to deal with overwatering which is a weakness of the Philodendron Black Knight (and other plants in the genus). If you overwater too much, you’ll soon notice yellow leaves and possible root rot.
Philodendron Black Knight Potting Soil
Potting soil is easy as well for the Philodendron Black Knight because you have a ton of options.
I like to stick with an Aroid mix for my philodendrons. You can check your garden center to see if they make this. Since there’s no fixed recipe, different shops will make their own. So, you’ll see different ingredients and amounts depending on who you ask.
But Aroids have similar characteristics. And, the mix that’s perfect for them fulfills all these needs.
For the Philodendron Black Knight, the best soil is on that will drain moisture quickly but hold enough liquid to hydrate the plant and keep the soil moist (I know, ironic, right?). It should also be light and loose so the roots get enough oxygen which helps prevent root rot.
And, it will appreciate rich, fertile soil.
If you can’t find an Aroid mix, here’s a recipe that works.
Aroid Potting Mix for Philodendron Black Knight
- 30% potting soil
- 40% orchid bark
- 20% peat
- 10% perlite
- Add some agricultural charcoal for good measure
The potting soil provides the nutrients and retains moisture. Peat also holds water to keep the soil moist. Orchid bark is chunky making giving the roots good air circulation. It also helps with drainage. Perlite likewise increases water drainage.
And, the charcoal, absorbs moisture, kills pathogens and provides extra aeration as well.
Adjust the breakdown depending on how the plant (and soil) responds.
Of course, if can simplify this by just using potting soil, perlite, bark and charcoal.
If you want to use the fewest ingredients possible, you can go with 100% sphagnum moss or a combination peat and perlite.
Fertilizer
The Philodendron Black Knight will grow faster and produce more leaves if you feed it correctly. And I stress the word correctly because it is very important.
Many beginners like adding fertilizer because they see the results. So, they keep adding and adding and adding. After a while, the plant gets sick and dies.
That’s because given a choice, it is better not to feed your plant than overfeed it. Too much fertilizer can damage and eventually kill your plant. In contrast, not feeding it will just make it grow slower. Eventually, it will get bigger (just takes more time).
So, like water, avoid too much fertilizer by all means.
This is especially true with the Philodendron Black Knight since it does not need a lot of plant food.
I like to use a balanced houseplant fertilizer. You can use different formulations, although I go with water-soluble (liquid) since it is easier to dilute and apply evenly. Diluting it to 50% or 25% of the recommended strength will reduce the risk of fertilizer burn.
The plant only needs once a month feeding during its growing season. There’s no need to feed it during the winter.
Pruning
Size is one of the differences between the Philodendron Black Knight and the Philodendron Black Knight.
The Black Knight can reach as tall as 9 feet high. Although indoors and in a container, it usually gets to anywhere between 2 and 5 feet with most in the middle of that range. If you let it climb it will also go up higher.
On the other hand, the Philodendron Black Knight only gets to about 3 feet tall. But is has much larger leaves which spread farther outwards. So, you can easily see them have breadths of between 1 to 2 feet from side to side. The larger leaves also make them attract more attention.
Of course, the Black Cardinal does not climb. So it only stays on the pot (or ground) and spreads outward and up.
If you have a Philodendron Red Emerald, it is worth noting that the Philodendron Black Knight will get bigger than that plant.
Because of the length of its stems and potential height, you may need to prune it. But, this is really out of preference.
I have not pruned mine outside of removing old leaves. I think because the plant’s leaves and stems make it look a bit sparse so I prefer letting it get bushy before doing any trimming.
How to Propagate Philodendron Black Knight
Because it has long stems, propagation is easy. This makes stem cuttings the go to method as they’re easy to procure.
Of course, if you’re used to layering, you can use that method as well.
I like stem cuttings for the simplicity of it. And, will only turn to the other methods if cutting is not an option. Note that some plants don’t root or have a hard time propagating through cuttings.
Anyways, here’s how to propagate Philodendron Black Knight using stem cuttings.
- Look for healthy stems. You can cut one or more depending on how many new plants you want to grow.
- Also, you can take single stems or stems that branch out to multiple, smaller stems. They both work for propagation. So you can take a bigger, thicker stem from the bottom or a stem higher up the plant.
- Ideally, choose a stem with at least 2 or 3 leaves on it. Make sure that the stem you pick has at least one node. If you take the stems near the base, check for aerial roots. You can take those as well.
- Get a knife, shears or scissors and cut the stem just below the node or aerial roots. Make sure to sterilize the blade with rubbing alcohol before using it.
- If you get a bigger stem, these will be thicker and firmer. Their size will also mean it is easier to pot them up in soil instead of water.
- For smaller, thinner stems, you can pot them up as well or propagate them in water.
- Use the potting soil recipes above to fill the pot and plant the stem cutting. You can apply rooting hormone on the end of the cutting as well. For safety purposes, you can opt to use a fungicide to prevent infections. Both are optional.
- It will take anywhere from 4 to 6 weeks for the roots to get somewhat established.
- During this time, water the moist and keep it moist. Also, leave the plant in a bright spot with no direct sunlight.
How to Repot or Transplant Philodendron Black Knight
The only time you need to repot your Philodendron Black Knight is when it has outgrown its pot. The main sign of this is roots coming out from the bottom of the pot or the surface of the soil.
- The best time to repot is during spring or early summer. Although if you live in a warm region where the sun is up all year long, the fall works just as well too.
- Use a container that is 2 inches larger than the current pot. if you’ve added a pole for your Black Knight to climb, you’ll want to be careful when moving it. The bigger and taller the plant gets, the more balancing and care is needed.
- Also, make sure the pot has drainage holes. Then, Fill the new container with fresh potting mix until about 40% or 50%.
- Finally, plant the root ball in and fill the remaining space with soil.
Is It Toxic/Poisonous to Humans, Cats & Dogs
Avoid leaving the plant near children and pets to play around. It is toxic when ingested especially the leaves since they contain calcium oxalate crystals.
Problems & Troubleshooting
Yellow Leaves
Yellow leaves can just be old leaves which the plant will eventually shed. You can remove them and not worry since this is part of its natural aging process.
However, if you see many leaves turn yellow at the same time, then something else is happening.
Often yellow leaves or brown ones too can be cause by too much light. If you see scorch marks or burn spots on the leaves, this means the sun is too strong or it is getting too much direct sunlight.
Moving the plant will fix this.
Also, trim off the damaged leaves or sections of the leaves. They won’t recover.
However, if the plant is not getting too much sun, then water is likely the cause.
Check the soil. Often it will be wet or soggy. That’s because overwatering causes yellow leaves. Thus, you’ll need to cut back on watering.
Leaf Tip Curling
When you see the tips of the plants leaves start to curl, it means you’re likely giving it too much fertilizer. Make sure that you only feed it during spring and summer when it is actively growing.
Also, avoid adding too much concentration or applying too often.
- The former can be prevented by diluting the dose by 50%. Also never water when the soil is dry.
- The latter has to do with frequency. Once a month feeding during its growing season is enough.
If you use a synthetic fertilizer, make sure to flush the soil once every 2 months or so. You can do so by pouring running water and soaking the root ball for about 3 minutes. Then let the soil drain after that.
The water will carry out excess minerals and salts along with other debris and small particles.
Avoid low quality, cheap fertilizers.
Pests
The Philodendron Black Knight is not too prone to pests. And, with proper care, you’ll likely never have to deal with these bugs. But, there are some pests like may come around.
The most common include scale, spider mites, mealybugs and aphids.
Diseases
Diseases are likewise rare. Although they are more preventable since most are caused by man.
Too much moisture is often the culprit. And because the plant enjoys high humidity, this makes moisture take longer to dry up.
As such, avoid wetting the leaves unnecessarily. And if they do, make sure there’s enough light and air circulation to let the leaves dry within the next hour.
Overwatering the soil can also lead to root rot. Since the plant can tolerate dryness quite a big, stay on the drier side to be safe.
