Rare houseplants are sure to generate a buzz among collectors and indoor gardeners, and few are more desired than Philodendron mexicanum. This gorgeous longleaf Philodendron can soon grow to accommodate any nook or cranny, creating a talking point in any room.

Finding one is difficult, but growing it doesn’t have to be. In this guide, our gardening pros explain the ideal growing conditions and reveal their top care tips and tricks.

What Is Philodendron Mexicanum?

Philodendron mexicanum is an evergreen, tropical climbing plant from the Araceae family, a group of plants commonly known as aroids. It is native to the rainforests of Mexico, but it can also be found in other parts of Central America, such as Panama, Guatemala, Costa Rica, and Ecuador. It was first described by botanist Heinrich Gustav Adolf Engler in 1878, and nowadays, it’s one of the rarest varieties of philodendron you will find on the market.

Philodendron mexicanum stands out among other philodendron species due to its showy, narrow foliage. The leaves are dark green, with a leathery feel and glossy shine, and well-defined lobes which give them the appearance of dogs’ ears.

In mature specimens, they can easily grow to a length of 2 feet (60 cm). The underside of the Philodendron mexicanum leaves is a rich shade of dark red or maroon, which adds to the plant’s charm.

When grown as an indoor plant, Philodendron mexicanum can grow up to 7 feet tall (2.1 meters). This vigorous climber is surprisingly easy to care for and can add a touch of exotic flair to any home.

– Is Philodendron Mexicanum Rare?

Philodendron mexicanum is still rare in the houseplant trade. Given the fact that each year new philodendron species and hybrids make their way on the market and are propagated more readily, there’s a chance that it will become more available. But for the time being, it is a rare find, and definitely worth adding to your collection if you come across it.

– Is Philodendron Mexicanum Toxic?

Yes. The stems and leaves of Philodendron mexicanum contain a toxic substance called calcium oxalate crystals. If it comes in contact with the skin, it can cause severe irritations and painful rashes. If the leaves are ingested by your cat or dog, they can cause nausea, excessive drooling, pain, swelling of the throat and mouth, and even difficulty breathing. Our recommendation is to keep this plant out of reach of pets and small children.

Philodendron Mexicanum Care Guide

Caring for Philodendron mexicanum can be very easy once you grasp its basic growing requirements. Like all philodendron plants, it prefers a humid environment, bright filtered light, regular watering, and, most importantly, a very well-draining soil mix. In this care guide, our expert gardeners will unpack their selection of tips and tricks that will help you grow this plant into a truly spectacular specimen.

Here’s what you need to know about growing Philodendron mexicanum indoors.

– Light Requirements

Philodendron mexicanum grows best in bright indirect light. In its natural habitat, you will find it growing in the understory of tropical forests, where it receives filtered sunlight trickling down through the canopy. But as the plant matures and starts climbing, it will need more light to stay healthy.

Our recommendation is to grow your Philodendron mexicanum in a room with eastern or western exposure. You can keep it close to a window, but use sheer curtains to filter out the sun. A couple of hours of direct sunlight in the morning and evening will promote larger leaf growth, but the direct midday sun can scorch the leaves. Similarly, too little light will result in leggy growth and smaller leaves.

– Temperature Requirements

The ideal temperature range for Philodendron mexicanum is between 65 and 75 F (18 to 24 C). This plant does not tolerate temperature extremes and will struggle to grow if temperatures rise above 86 F (30 C), or drop below 55 F (13 C).

It’s also sensitive to hot or cold drafts, so make sure to keep it away from any radiators, heating and cooling vents, as well as drafty windows and doors.

If you want to grow Philodendron mexicanum outdoors in your garden, you can do so in USDA zones 10 to 12. We recommend picking a part of your garden that receives dappled sunlight throughout the day. You can also plant it next to a tree, and the philodendron will start climbing it in no time. This plant is an epiphyte, and it won’t damage the tree by soaking up nutrients, the way parasitic plants would.

Philodendron mexicanum is not frost hardy and can suffer permanent root, stem, and leaf damage if exposed to temperatures below 50 F (10 C) for too long. If you live outside USDA zones 10 to 12, our suggestion is to keep it in a pot and bring it indoors when it gets too cold during the night.

– Water Requirements

Keep the soil of your Philodendron mexicanum moist but not soaked. The plant can be very sensitive to root rot and having ‘wet feet’, but at the same time, it does not tolerate drought.

Watering your Philodendron mexicanum can be a bit tricky if you’re a beginner, but it’s something you’ll get a hang of pretty quickly. To keep it healthy, allow the soil to dry out to a depth of one inch between waterings.

Then, use the soak and drain method to water the plant. Slowly pour water through the soil, until you see it drip through the drainage holes, then allow the pot to drain for 10 – 15 minutes before placing it back on its tray.

Your Philodendron mexicanum watering schedule will change depending on the size of the pot, the age of the plant, how humid your home is, and also the season. In spring and summer, you may have to water it once a week, then cut back on watering to once every 7 – 10 days during the colder months. If you’re not sure if your philodendron needs more water, simply test the top inch of the soil to see if it’s dry, then give the plant a good soak.

– Humidity Requirements

Philodendron mexicanum is a tropical plant that loves high humidity. A humidity level of around 50 percent can work for this plant, but 80 percent is ideal. This is significantly higher than the average home humidity, but there are a few tricks you can use to boost the moisture in your home.

  • Place the pot on top of a pebble tray. The water evaporating from the tray will help increase the humidity around your philodendron.
  • Use a humidifier. The easiest way to reach a humidity level of 70 percent or higher is to use a humidifier for your plant. It is a worthwhile investment, especially if your philodendron is the only plant you have in that room.
  • Group plants together. Plants that grow together thrive together. The water evaporating from the soil and through leaf transpiration helps create a humid microclimate. Try growing your philodendron next to other plants that need a lot of moisture, such as Calatheas or ferns.
  • Keep your plant in a humid room. Bathrooms and kitchens are typically more humid than your living room, for example. If you plan to keep your philodendron in a bathroom, make sure that it has a window so that the plant can receive adequate sunlight.

Does Philodendron mexicanum like being misted? The answer is yes, although this is not a very efficient method to increase the humidity for your plant. Also, without good air circulation, the plant can be at risk of fungal diseases or leaf spot. Rather than misting your philodendron, our recommendation is to keep it on top of a pebble tray, and regularly wipe its leaves with a damp cloth. This is a good way to boost humidity, as well as keep the leaves clean.

– Soil Requirements

The soil mix for your Philodendron mexicanum should be loose, aerated, porous, rich in organic matter, and very well-draining. In the wild, this plant can be found growing on trees but also rocks, which means that its roots have adapted to a moist substrate that also doesn’t retain water for too long. Creating a soil mix that mimics these features is crucial if you want to keep the roots healthy and prevent problems caused by overwatering.

Most growers recommend using soil-less potting mixes for Philodendron mexicanum. Universal potting soil is too thick and heavy for philodendrons, and it lacks the drainage and airflow these plants need. Here’s a great mix we recommend using instead:

  • one part coir
  • one part peat
  • one part perlite or pumice
  • one part orchid bark

You can also add a handful of horticultural charcoal to the mix. This will help increase the chunky consistency of the soil, and the charcoal’s antifungal and antibacterial properties will protect the roots from rot. A handful of worm castings will also give the plant a nutrient boost.

– Fertilizer Requirements

To encourage healthy leaf growth, we recommend giving your Philodendron mexicanum a monthly fertilizer application throughout spring and summer. You can use a liquid, universal fertilizer that’s diluted to half the strength. A nutrient ratio of 10-10-10 should do the job, although you can dial up the nitrogen to 20-10-10 if you want your philodendron to produce large, lush leaves.

The Philodendron mexicanum grows much slower in winter, so it won’t need any fertilizers during the colder months. Feeding your plant during this brief period of dormancy can result in stress, with symptoms such as leggy growth. Keep in mind that the soil in the pot also stays damp for longer in winter, and the combination of damp soil and fertilizers can attract pests such as fungus gnats.

– Pruning and Maintenance

Philodendron mexicanum doesn’t typically require pruning. Occasionally, you will need to remove some of the older, yellowing leaves from the bottom of the plant. If your philodendron is growing too tall for the space you have, you can cut back some of the plant and use it for propagation. Always sterilize your tools with rubbing alcohol before pruning your plant, to prevent the spread of pests and pathogens.

– Does Philodendron Mexicanum Need a Climbing Pole?

Yes. Philodendron mexicanum is a climber, so we recommend providing it with some form of support, preferably a moss pole. You can easily make one from hardware mesh rolled into a tube. Fill the tube with sphagnum moss, and use cable ties to attach the stem to the pole. Mist the moss pole every day to keep it moist, or pour water through it from the top. The aerial roots will gradually start digging into the moss, keeping the plant upright.

Using a moss pole for your Philodendron mexicanum has several benefits. On one hand, it provides the plant with a growing environment that’s closer to what it’s used to in its native habitat. It also helps the plant produce larger leaves.

In the wild, philodendron plants will use their aerial roots to climb trees and other vertical surfaces, in search of sunlight. The higher they climb, the bigger their leaves get to help the plant absorb as much light as possible. So if you want your Philodendron mexicanum to grow lush, large leaves, using a moss pole is a must.

– Repotting Philodendron Mexicanum

The Philodendron mexicanum growth rate is quite fast, and, under the right conditions, this plant can grow more than 3 feet (90 cm) in height each year. Depending on its environment and how fast it’s putting out new leaves, you may need to repot it once every one or two years. Always check the underside of the pot first. If you can see roots coming through the drainage holes, that’s a sign that your philodendron needs a bigger pot.

The best time to repot Philodendron mexicanum is in mid-spring or summer, during the plant’s growing season. Gently lift the plant from the pot, and remove as much of the old soil as you can to untangle the roots. If your philodendron is really tall, you may need another person to help you, to prevent any damage to the stem and leaves while handling the plant. Then simply repot the plant in a pot that’s one size larger, or 2 inches (5 cm) wider.

When it comes to the type of container to use for Philodendron mexicanum, a plastic pot should do the job nicely. This material prevents the soil from drying out too fast. You can also use ceramic or terracotta pots, especially if you have a very tall plant. If you’re not using plastic pots, remember to check the soil more frequently, as clay and terracotta will quickly wick out moisture from the soil. Whichever type of container you use, always make sure that it has at least one drainage hole at the bottom, to prevent the roots from sitting in water.

Philodendron Mexicanum Propagation Guide

You can propagate Philodendron mexicanum using either stem cuttings or air layering. Both methods are best used in spring or early summer when the plant is actively growing. Let’s take a closer look at each method.

– Philodendron Mexicanum Stem Cutting Propagation

  • Use a sharp, sterilized blade and cut the stem half an inch below the growth node.
  • You can use a cutting with just one leaf for propagation, although cuttings with two or more leaves typically root faster.
  • The cutting can be rooted in either water or a well-draining soil mix. If you’re rooting it in water, remember to change the water once every 5 – 7 days.
  • Keep the cutting in a warm, humid spot, away from direct sunlight.
  • The cutting will start developing roots after about two weeks. Once the roots are at least 2 inches (5 cm) long, you can plant the cutting in soil.

– Philodendron Mexicanum Air Layering Propagation

Air layering is a propagation method that stimulates the plant to grow its aerial roots without cutting the stem from the main plant. This method is a lot less invasive for the plant than using stem cuttings, and it also minimizes the risk of losing a cutting if it doesn’t root. It’s also a common propagation found in the wild, and often, philodendrons that are knocked off trees during a storm will simply start growing their aerial roots into the soil instead.

Here’s our step-by-step guide for propagating Philodendron mexicanum through air layering.

  • Find a growth node on the stem of your philodendron.
  • Take two handfuls of damp sphagnum moss and pack it around the node. Use some plastic wrap to keep the moss in place, but leave a gap at the top and bottom of the wrap.
  • Keep the moss damp by misting it or trickling water through it every day. In the meantime, you can care for your philodendron plant as usual.
  • After a couple of weeks, the node will start to develop roots. When you see the roots coming through the bottom of your moss wrap, remove the moss, cut the stem half an inch below the node, and plant it in a well-draining soil mix.

Common Pests and Problems

Philodendron mexicanum is resistant to most pests and diseases, but its health can decline if it’s not growing in the right conditions. Here are a few signs to watch out for.

– Brown Leaf Spots

Brown leaf spots on your Philodendron mexicanum are typically caused by fungus or bacteria. If your plant is living in very humid conditions and poorly draining soil, it can be very susceptible to leaf spot disease. Move your philodendron away from your other plants to prevent spread, trim the infested leaves, and spray the plant with a copper fungicide.

– Yellowing Leaves

It’s normal for some of the older leaves on your Philodendron mexicanum to turn yellow as the plant matures. But if you notice that most of the leaves are turning yellow, especially new growth, this could indicate that your plant is overwatered. Always allow the soil to dry to a depth of an inch before watering it again, and use a very well-draining potting mix.

– Soft, Brown Leaves

If the leaves on your Philodendron mexicanum are developing large brown spots that have a soft texture, this could be a sign of root rot. Take the plant out of the pot and inspect the roots. Use a sterilized blade to trim the ones that are brown and mushy to the touch. You can also wash the roots with a fungicidal solution, to prevent them from getting infected again. Throw away the old soil, sanitize the pot with a bleach solution, then repot the plant in a fresh mix of well-draining soil.

– Pests

The most common pests for Philodendron mexicanum are scale, mealybugs, spider mites, and thrips. They can cause leaf discoloration, wilting, distorted foliage, stunted growth, and in severe infestations, they can even kill your plant.

For spider mites, mealybugs, and scale we recommend wiping the leaves with a solution of water and isopropyl alcohol. Thrips can be a bit more difficult to get rid of, because their larvae live inside the plant tissue, effectively eating the leaf from within. Trim off any badly infested leaves, then spray the plant with an insecticidal soap solution.

Conclusion

Philodendron mexicanum can make a wonderful addition to your home and caring for it is a piece of cake when you know a few little tips.

Let’s cover the basics one more time:

  • Philodendron mexicanum has a fast growth rate and can reach almost 7 feet in height, with leaves that are about 2 feet long. To encourage large leaf growth, we recommend giving your philodendron a moss pole to climb on.
  • Keep the plant in a humid room where it receives bright indirect light, water it regularly, and make sure it’s potted in a well-draining soil mix.
  • In spring and early summer, you can propagate it using either stem cuttings or through air layering.
  • Philodendron mexicanum is toxic to cats and dogs, so remember to keep it in a room where your pets won’t get to it.

Now that you know how to grow Philodendron mexicanum, the hardest part is finding one for your home!

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