Creating philo cultivars has been quite the rage in recent decades, providing us with many spectacular new breeds.
One of these is Philodendron (fil-oh-DEN-dron) ‘Rojo Congo,’ a cross between Philodendron Imperial Red and Philodendron tatei.
It was first created in 1996 by Marian Wincenty Osiecki and officially patented in 2003 to Oglesby Plants International, Inc. of Altha, Florida, under the name Philodendron ‘Rojo Congo’ (patent no. PP14116).
While the official name is ‘Rojo Congo,’ it is more popularly known as ‘Congo Rojo’ but may also be referred to as Congo red, Philodendron’ Red Congo,’ and red philodendron.
The Spanish term “Rojo” refers to the distinctive red tint of its young leaves.
Philodendron ‘Congo Rojo’ Care
Size And Growth
This plant is officially described as being self-heading but also “mostly upright,” meaning you may still wish to provide some support if you wish for it to achieve the maximum potential height.
This confusion has led to many sites describing the plant as self-heading while others describing it as a climber. Neither description is technically wrong, and your mileage may vary.
Under optimum conditions, ‘Congo Rojo’ is a fast grower that can achieve a shrublike size of up to 10’ feet tall and wide.
Of course, the real show is in the foliage, which initially unfurls into a shade that resembles a mix of brown, maroon, purple, and green with slight variation in hues.
The leathery, glossy leaves are asymmetrical and broadly ovate, reaching nearly 18” inches long and around 11.8” inches wide.
As they mature, the leaves turn to a more traditional dark green color on top and a brownish-green on the underside.
The upper leaves will have a more vertical growth habit, while lower leaves tend to be more horizontal.
The midrib can vary in shades of green, while the primary veins tend to be slightly lighter.
For more information on how this cultivar differs from other, similar philodendron cultivars, please refer to the patent description.
Flowering And Fragrance
As with most philodendrons, getting this plant to bloom indoors is almost impossible.
When it does, it’s an unremarkable group of 1 to 3 white inflorescences that are almost entirely obscured by the foliage.
As this plant is a cultivar, there’s no value in the inflorescences or their seeds, so you will likely want to remove the blooms if they appear to encourage plant growth.
Light And Temperature
Bright, indirect light is the secret to this plant’s success.
While direct sunlight can easily scorch the leaves, the brighter light encourages growth and better coloration.
Direct morning or evening sun with afternoon shade is a good option.
However, the plant can also grow under adequate artificial lighting, and some growers prefer to keep the plant in light shade conditions, resulting in a smaller, more compact plant.
NOTE: The Gaylord Palms Resort in Orlando, has some beautiful specimens.
‘Congo Rojo’ will exhibit healthy growth with humidity levels as low as 45% to 50% percent but will thrive at 70% percent or higher.
Be sure to give it a pebble tray or humidifier, especially during the winter months.
While cold-sensitive, Congo red is a little more tolerant than many other philodendrons but cannot handle anything under 54° degrees Fahrenheit.
Ideal temperatures are around 68° to 78° degrees Fahrenheit during the day and about 60° degrees Fahrenheit at night.
Avoid exposure to drafts or other sudden temperature shifts.
The ideal place to grow this plant outdoors is in USDA hardiness zone 12, but there have been some claims of success in zones 9b and warmer with adequate protection from the cold.
Watering And Feeding
Don’t believe what other sites tell you when they say this plant is hard to grow because most will give away their true difficulty when it comes to watering.
A simple pro tip is to NEVER water plants on a schedule, as this can easily lead to overwatering or underwatering.
Do YOU drink specific amounts of water at specific times per day? Neither does your plant.
Instead, use the soak-and-dry method by sticking your finger in the soil.
Follow these steps:
- Water it when the soil is dry 2” inches down.
- Pour room-temperature water slowly and thoroughly, working your way around the plant and avoiding getting the foliage wet.
- Stop when you see moisture beginning to seep from the drainage holes or the surface can no longer absorb at the same rate you’re pouring.
This ensures the soil is evenly moist but not wet.
There is always some debate on whether a plant is a light or heavy feeder, but this plant is a fairly light feeder despite some claims to the contrary.
Here are the following tips for feeding:
- Give the plant a dose of balanced liquid houseplant fertilizer monthly in spring and summer.
- Start off at 1/3 strength and adjust according to your plant’s response.
- You may need to supplement with calcium (simply stir crushed, clean eggshells into boiling water and let it steep overnight for an effective calcium booster) or magnesium (a teaspoon of Epsom salts will fix this).
Soil And Transplanting
A light, well-draining soil is perfect for this cultivar.
Cactus potting mixes are popular, especially with a bit of added perlite.
You can also use pure sphagnum moss or an equal mix of peat moss, vermiculite, or perlite.
However, a popular soilless recipe involves:
- 8 parts coconut coir
- 3 parts of orchid bark
- 3 parts perlite
- 2 parts activated charcoal
- 2 parts pumice
- 2 parts worm castings
Terra cotta or ceramic containers tend to be heavier but will be more attractive and more beneficial for the plant since they’re less likely to tip over.
However, you will need to graduate a pot size larger in the spring if you see roots beginning to poke out of the drainage holes or soil surface.
During this time, make sure to give it a fresh batch of your potting medium.
Even when fully grown, you’ll want to repot the plant every 2 to 3 years to ensure it has a fresh potting medium.
Grooming And Maintenance
Pruning is rarely necessary, with the primary reason for shaping or removing diseased or heavily damaged leaves.
In many cases, growers will simply trim a leaf to get rid of brown tips, following the natural shape of the leaf.
You will want to wipe down the leaves once or twice per week to remove any dust.
How To Propagate Congo Red?
It can be tough to propagate ‘Congo Rojo’, as the stem usually lacks obvious nodes.
However, once mature, it will produce plantlets at its base, and it’s also possible to use stem cuttings or air layering with a bit of patience.
Note that it is illegal to propagate for distribution or sale as a patented plant without permission from the patent holder.
Red Philodendron Pests Or Diseases
Philodendrons are known for being resistant to most pests and diseases, especially cultivars.
‘Rojo Congo’ is no exception, with the most common risks including:
- Spider mites
- Root rot
As is the case with all philodendrons, the plant has high levels of calcium oxalate, making it toxic to both humans and pets.
Some individuals may also have an allergic reaction to the sap of this particular cultivar.
Philodendron ‘Rojo Congo’ Uses
This isn’t a small plant by any means, although growers have reported sizes as small as 4’ feet tall when kept in low-light conditions.
This smaller size is good for tables or shelves.
Meanwhile, the full-size plant can be used as an outdoor shrub or attraction in larger areas such as lobbies.
They can also make bold statements in offices with enough space to let them thrive.