Philodendron Imperial Red Care – Botanist’s Complete Guide

If you’re looking to add yet another tropical plant to your collection, look no further than the philodendron imperial red. It produces magnificently wide, ridged waxy leaves held by thick brown, red or even fuchsia colored stems.

New leaves start off a marooney red or pink before transforming into a deep emerald green. As they mature and age, they kind of ‘revert’ back to their juvenile form and their leaves start to become more red again, hence the name philodendron imperial red.

If you already have this beauty in your collection, keep reading to discover the best tips and tricks for philodendron imperial red care!

Philodendron Imperial Red Origin & Backstory

Like most plants from the philodendron family, the philodendron imperial red is native to Central and South America as well as the West Indies. It hails from the deep tropical or even subtropical canopies in these region’s rainforests. It’s a fairly new hybrid variety that was bred specifically to enter the commercial market, similar to the philodendron prince of orange and rojo conjo. 

Quick Note: If you have a plant that has the same textured, glossy leaves but they have a medium to dark green color rather than red tinge, you likely have a philodendron imperial green instead.

Light

The philodendron imperial red thrives in lots of bright, indirect light. My imperial red is 2-3m away from an east facing window and so far loves it.

From my experience, an hour or two of direct sun in the morning does this plant a whole lot of good. The problems arise when it’s keep in direct sun for the entire day. 

It can tolerate moderate light too, but I definitely wouldn’t keep it in a fully shaded or very low light position.

From a scientific point of view, those gorgeous darker leaves signal that this plant has a much higher concentration of chlorophyll in its leaves than say a lemon lime philodendron, which means it’s genetically primed to capture as much light as possible.

Soil

Imperials love a well-draining potting mix that’s rich in organic content. I keep mine in a mix of high quality potting soil, coco coir and perlite. Perlite is added for drainage whilst the potting soil and coco coir help to retain some moisture. This is a very peaty mix.

Too many fast-draining elements in a mix will mean that it becomes too hard to keep moist. A pot containing all soil, coir or peat moss will hold too much moisture. It’s best to find a balance between the two. 

Watering

To keep the root ball damp, you’ll want to make sure the top 1-2 inches (3-6cm) of potting mix is moist 60-70% of the time. I’ve found that this plant likes to dry out a little in between waterings, but never to a point where the soil is clumped or is pulling away from the pot.

Moist means damp to touch, but not waterlogged or boggy. Nothing will kill this plant quicker than overwatering. 

Pro Tip: Overwatering isn’t caused by how much water you use, but rather the frequency of watering. Excess water in a fast-draining potting mix will always find its way to the drainage holes providing the soil isn’t sticky or clumped from being waterlogged.

If you’re new to keeping philodendrons, it’s best to err on the side of drier than wetter. Try watering once a week, making sure to give it a thorough watering.

If the soil isn’t drying out in between waterings or the tips of the leaves are turning yellow, then it’s likely too much water.

Similarly, curling leaves are a good indicator that your plant isn’t getting enough water! It’s about finding what’s right for your plant. 

If you live in a hot or humid region, you’ll need to water this plant more frequently than me for example who lives in the UK. 

Fertilizer

The best fertilizer to use with the philodendron imperial red is a diluted, complete liquid fertilizer. Complete simply means it contains all of the major macro, secondary and micro nutrients a houseplant needs to thrive indoors. 

Best Fertilizer to Keep Your Imperial Red Thriving

I love and use dyna grow pro, the 7-9-5 formula. It is a premium, complete formulation and I use it on the vast majority of my houseplants. It contains 16 essential nutrients plants need to thrive and its very low in urea (which is what you’re looking for!).

Urea, when in high quantities, can cause a residue build on the soil’s surface, which overtime will change the pH level and cause dreaded root burn.

Urea is one of those heavy nitrogen salts you’ve probably read about before on other plant websites or nurseries. It’s one to definitely avoid where possible.

How to Fertilize The Imperial Red Philodendron

Okay, so I water and fertilize my plants at the same time. By this I mean I fertilize my plants every time I water them (except in autumn and winter).

This might sound excessive, but it’s how these plants naturally feed in the wild. In their native habitat, they receive a small, steady stream of nutrients over time rather than a huge gulp all at once.

I take ¼ teaspoon of dyna grow pro and dilute it with 1 gallon of water (4.5 litres), and water like normal using this pre-made batch. This will NOT burn your plants – it’s diluted to half strength and then diluted again. Plus, you’ll never forget to feed your plants!

Alternatively, you can whip up a batch of half strength fertilizer and feed once a month separately. Simply dilute to half the recommended amount on the brand/bottle you buy.

Pro Tip: Fertilize away from the stems and leaves i.e. on the outskirts of the pot so you don’t accidentally pour fertilizer solution directly onto your plant. 

When Should I Fertilize my Philodendron?

Fertilize your philodendron in spring and summer. If you’re using my fertilizing method, fertilize every time you need to water using the double diluted solution – usually 4 times a month (for me). In autumn, I cut back on fertilizer, and in winter I don’t fertilize at all.

If you’re using half strength fertilizer, fertilize once or twice a month in spring/summer, cut back in autumn and again don’t fertilize in the colder months.

Tip: When the plant’s not actively growing, it’s more susceptible to root burn and overwatering. It needs much less nutrients and water!

Key Nutrients to Look For in a Fertilizer

Nutrients to look for in a fertilizer include the 3 major macronutrients – nitrogen, phosphorus and potassium.

Nitrogen promotes foliage or leaf growth, phosphorus helps the plant convert energy into building blocks for new tissue and cells, whilst potassium promotes a healthy root system.

You’ll also want some secondary nutrients e.g. calcium and magnesium as well as micronutrients such as iron and zinc. 

Most high quality fertilizers contain these nutrients. Double check the label before purchasing.

Cheap Fertilizer vs Premium Fertilizer – What’s the Difference?

Cheap fertilizers often don’t contain a healthy balance of nutrients, and they’re usually loaded with heavy nitrogen salts which will lead to root burn if the soil isn’t flushed frequently (trust me, I made this mistake and it’s a pain – flushing if not done right can also lead to waterlogged soil).

Premium fertilizers are more expensive but there’s usually a good reason for it – they contain higher quality nutrients, are lower in salts and can promote better soil structure. 

Can I Use an Organic Fertilizer?

You sure can! Alaska fish emulsion is AMAZING stuff. I’ve used it on my philodendron hastatum as well as my philodendron micans and the foliage growth is crazy. It tends to have a 4-1-1 or 5-1-1 NPK ratio, so it’s lower in phosphorus and potassium, but it’s rich in nitrogen.

Friendly advice, the stuff stinks. I now only use it on my outdoor plants before I bring them in for winter.

Other less stinky organic alternatives to use are kelp and seaweed extract (doesn’t smell), compost tea or worm tea. 

Tip: You don’t need to double up on fertilizers. If you’ve got a complete formulation, you don’t need an organic fertilizer. 

Can I Use a Granular or Slow Release Fertilizer Instead?

You can, but make sure your fertilizer has a ‘no burn guarantee’ stamped somewhere. It’s hard to measure how much fertilizer your plant is getting every feed so you’ll want to make sure it’s got little to no chance of burning the root system. 

Tip: I don’t recommend Osmocote – it switched its formula in April 2021 and now uses microplastics to release the nutrients. You’re then left with thousands of plastic pieces in your soil. Not good, nor eco-friendly.

Temperature

Plain and simple, the philodendron imperial red is a heat lover! The warmer the better, anywhere between 65-85 Degrees Fahrenheit is ideal.

Anything lower than 55 Degrees Fahrenheit (12 Celsius) will result in stunted growth.

Humidity

Being a tropical plant, it’s no surprise the imperial red loves humidity. It can cope with normal household humidity e.g. 40-50%, but it will produce the most gorgeous leaves with a humidity level of 70% or higher. Think thicker, darker and wider foliage.

Grouping your plants together is a good way to increase humidity naturally. Grouping helps plants share humidity resources through a process known as transpiration. Effectively, you’re creating a mini biome which helps ALL your plants to function more efficiently.

Alternatively you could invest in a good ol’ humidifier or line a tray with pebbles, fill the tray halfway with water and place the pot on the stones (not in the water).

Repotting

This plant doesn’t seem too fussy when it comes to being root bound. It seems to cope with it better than it does regular repotting. Repotting once every 2-3 years is more than okay. 

Signs your philodendron imperial red needs repotting includes:

  • Roots shooting through the drainage holes of the pot
  • Very slow growth even in spring

When repotting, consider the following:

  • Choose a pot that has good drainage
  • Choose a pot that is 2-3 inches wider than the last (no bigger)
  • Select a well-draining potting mix

Pruning

The imperial red doesn’t need much pruning. It just needs some occasionally pruning to remove a dead, yellowing or diseased leaf.

As always, prune with a clean pair of pruning scissors that have been sterilized in rubbing alcohol first.

How to Propagate your Philodendron Imperial Red

So, this plant was specifically bred to be a ‘manageable houseplant cultivar’, meaning it was designed to not climb and not grow out of control.

As a result of this genetic feature, this plant doesn’t have any nodes or internodes to get stem cuttings from, so taking a cutting isn’t going to work for propagation.

Plants that are self-headers such as the imperial red are fairly difficult to propagate as a home grower.

Botanists or nursery growers will use a method called tissue culturing or seed propagation – neither are feasible for the home enthusiast. However, you can plant what we call ‘plantelets’ which the imperial red develops as it matures and air layer them.

Philodendron Imperial Red Propagation Methods – Step by Step

Make sure to propagate at the beginning or spring or summer to really increase the success rate. This is one of the MOST important factors to get right when propagating this plant.

Helping Plantelets to Grow

  1. Search for little platelets at the base of the plant. Plantelets will grow where old leaves have died off.
  2. Wait until it has a visible stem and aerial roots emerging. Placing the imperial red in a bright location will help these grow quicker.
  3. 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.
  4. When ready, cut the plantlet off the mother plant and pot it in a well-draining, rich soil mix.
  5. Care for your philodendron imperial red as usual..

How to Air Layer your Philodendron

  1. Look for the small aerial roots shooting out of the plantelet.
  2. Take some wet sphagnum moss, and wrap it around the aerial roots.
  3. 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.
  4. 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!).
  5. Leave the top and bottom of the seal open. New roots like to dive downwards and this helps them do so without bunching up.
  6. 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.
  7. Wait 2-3 weeks for new roots to develop.
  8. 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)
  9. Cut the plantelet just below the new roots with clean scissors.
  10. Pot the plantelet in a wet sphagnum moss bundle, ideally in a clear pot so you can see root growth. I normally don’t pot in any other medium because it’s clearly already doing well in moss so I don’t change it until it’s more established.

That’s it! I prefer to use the air layering method where possible because there’s less risk. You only cut the plant when roots have developed, not before.

Growth – How Big Does a Philodendron Imperial Red Get?

You might be surprised to discover that the philodendron imperial red is not a compact plant. It commands way more space than many people think thanks to its thick, but wide bodied stems.

It LOVES to spread its leaves out.

Not only does it grow wide, but it can also get quite tall growing up to 4 feet or 120cm in height. Despite this, it is only a moderate grower, not fast like the philodendron micans!

Toxicity – Is the Philodendron Imperial Red Toxic?

Yes, the philodendron imperial red is toxic to small children and pets, including dogs and cats. If ingested, it can cause some local swelling in the mouth and gastrointestinal tract.

Help! What’s Wrong with My Plant? – Common Care Problems with the Philodendron Imperial Red

Problem #1 – The leaf tips are turning brown

Leaf tips turning brown is usually an indicator your plant is craving more humidity. You’ll typically have to look quite closely to see them as they don’t take over the whole leaf. 

Problem #2 – The leaves are curling

Curling leaves can be caused by a few things including pests and water issues. The main culprit in this plant is a lack of water. Typically leaves can start to curl within a day or two of being in an environment that’s too dry. 

Problem #3 – Brown spots are starting to appear on the leaves

Brown spots are pretty uncommon, but it’s usually a sign of over fertilization or more specifically root burn. Change the potting mix or flush out the current pot and make sure to dilute to either half or a quarter the recommended fertilizer strength.

Problem #4 – Philodendron imperial red leaves are turning yellow

If your philodendron imperial red plant has leaves that are turning yellow this is a good indicator that you’re overwatering it. Philodendrons don’t like overly wet soil. Check the root system for root rot (black, foul smelling roots) and change the potting mix. I find this is the quickest way to prevent root rot from taking hold or getting worse.

Note: Yellow leaves can also be an indicator of pests.

Problem #5 – The leaves are changing colors. Is this normal?

As the plant ages and matures, the leaves will turn from a deep burgundy or maroon red or even pink to a deep emerald green before transforming to a green leaf with a reddish tinge. This is completely normal.

If the leaves are turning brown or yellow though, this is not normal and indicates another care problem.

Problem #6 – My philodendron has root rot. What Do I Do?

Root rot is fairly common amongst philodendrons. It’s typically caused by overwatering combined with chronic underwatering which causes the soil to compact and the roots to shrivel up. This means the plant can’t absorb the water well, and the oxygen supply is cut off. 

If your plant is suffering from root rot, change the potting soil as fast as possible (no need to pry the soil from the roots) and if possible take some plantelets to propagate just in case it doesn’t survive.

Problem #7 – The leaves are turning brown

Leaves turning brown can be caused by either too much direct sun, underwatering, pests or overfertilization. This is a tricky problem to solve because it’s difficult to know which problem is causing the issue. 

Problem #8 – Pale leaf color

If the beautiful red tinge color of the leaves starts to fade or turn more a deeper green, this is a sure sign your philodendron imperial red needs to be moved to a brighter location. Low light locations drains the leaf color and causes an off pale color to appear.

Problem #9 – My plant is developing wet, mushy translucent spots

These wet mushy spots are caused by erwinia blight disease, a moisture loving bacteria that develops as a result of too much overhead watering. If left untreated, it can kill your plant within days so acting fast is crucial. Change your plant’s potting soil, trim any diseased leaves and if you have platelets with good aerial roots, I’d save them if possible.

Common FAQ – Your Questions Answered

Should I Mist my Plant?

I don’t recommend misting any of your plants. Misting does nothing to increase humidity despite what you’ve been led to believe! If anything it’s been shown to promote bacterial infections that thrive on moisture e.g. erwinia blight disease. It’s extremely difficult to know when you’re overdoing it.

Is the Philodendron Imperial Red Plant Rare?

The philodendron imperial red is abundantly available in its natural habitat and is an easy to care for, popular houseplant.

Does the Philodendron Imperial Red Climb?

No, the philodendron imperial red is a self-heading plant, which means it has thick, tough and rigid stems sturdy enough to support its growth as it matures.

Philodendron Imperial Red vs Black Cardinal – What’s the Difference?

The philodendron imperial red and black cardinal look fairly similar. The only difference between the two is that the black cardinal produces smaller, shorter leaves and instead of producing a reddish foliage, it develops rich chocolate colored leaves. Black cardinals start off with lighter bronzy, almost orange shades of color until they eventually mature into a chocolate or even black appearance.

Philodendron Imperial Red vs Imperial Green – What’s the Difference?

Whilst they’re both a hybrid variety and both produce stunning large, glossy leaves, the imperial red philodendron produces red leaves whilst the philodendron imperial green only produces green leaves. The imperial green will never exhibit orange, red or brown foliage. 

Should I clean my plant?

Yes, part of good philodendron imperial red care includes cleaning the dust off your plant’s leaves. With a clean smooth cloth and some lukewarm water, wipe your plant’s leaves to keep them looking glossy and shiny.

Leave a Comment