Philodendron ilsemanii – complete guide to this super-rare house plant

Philodendron ilsemanii

Overview

Philodendron ilsemanii, commonly called the Ilsemanii Philodendron, is a beautiful foliage plant.

It is a tropical evergreen vine native to Ecuadorean rainforests at elevations around 4,500 feet. It can reach lengths between six to ten feet as a houseplant.

Ilsemanii Philodendron has long trailing stems covered with large, deeply lobed leaves. The leaves can reach lengths up to 14 inches long and emerge with a reddish tinge before maturing to a rich green.

Given proper care and conditions, this plant eventually forms impressive hanging baskets or can be trained up a moss pole.

Compared to other foliage plants, like Golden Pothos for example, Philodendron ilsemanii is rare and can be difficult to find in plant retailers, and likely to be incredibly expensive if you do find one. Cuttings and small specimens are often for sale for upwards of $800 on E-bay and specialist plant collectors sites.

Why is Philodendron ilsemanii so expensive?

One reason why the Philodendron ilsemanii comes with such a high price tag is because it is extremely rare. As mentioned, this philodendron variety grows natively in only a small region of Ecuador.

This means there is not a huge supply of seeds or vegetative material for propagation. That makes it hard for growers to propagate and cultivate the plant large numbers.

As a result, the scarcity of the plant drives up demand from plant collectors, and increased demand hikes up the price.

Another part of price equation for Philodendron ilsemanii is its unique and eye-catching appearance. The base colour of the leaves are of a deep green colour with prominent silver-coloured veins running through them.

This is overlaid with the irregular blotchy cream variegation seen in the image above. This creates an intricate, attention-grabbing pattern across the foliage.

What is more the leaves themselves are thick and leathery and grow very large, sometimes reaching lengths of 12 to 14 inches.

So whilst you might think twice about parting with the cash to buy Philodendron ilseamnii, you can probably see its attraction.

Origins of Philodendron ilsemanii

The name Philodendron comes from Greek and means “tree loving”. These plants are called Philodendrons because they cling to tree trunks as they grow in their native jungle habitats.

The origin of Philodendron ilsemanii is a bit uncertain. For example, it is not known whether it is a naturally occurring species or a cultivated hybrid.

There are some suggestions that it could be a variegated variety of the Philodendron corcovadense species, but this has not been confirmed.

Likewise, although they are sometimes confused with each other, it is thought that Philodendron ilsemanii is not the same plant as the variegated Philodendron imbe, the Philodendron x domesticum, or a variety called ‘Jose Buono’.

The Kew Gardens plant database suggests that Philodenron saggittifolium is the same plant, although there is also doubt about this.

There is only one official recorded specimen of Philodendron ilsemanii, which is a drawing from the 1908 Ghent International Exhibition.

“Philodendron sagittifolium” in its native habitat by Neptalí Ramírez Marcial – CC BY 4.0

Growing Conditions

Philodendron ilsemanii can be grown in containers or hanging baskets. Choose a pot at least 2 inches wider than the root ball with drainage holes.

Position in a bright spot 6-10 feet away from a sunny window. Maintain temperature and humidity levels to replicate tropical conditions.

Water when top inch of soil is dry. Check for pests like spider mites that hide on the undersides of leaves.

Follow our more detailed care guide below:

Philodendron ilsemanii care guide

  • Light: Bright, indirect light, away from direct sun (see the image below). Provide at least four hours of sunlight daily. Low light causes small foliage growth.
  • Water: Allow soil to slightly dry out between waterings. Water less frequently in winter. Yellow leaves indicate overwatering.
  • Humidity: High humidity levels between 50-80% should be maintained. Increase moisture with a pebble tray or humidifier. Mist leaves daily.
  • Temperature:
    • Ideal: 17-27°C (60-80°F)
    • Minimum: 12°C (54°F)
  • Soil: Well-draining potting mix, but add lots of organic matter to increase water retention capacity
  • Fertilizer: Feed monthly during growth season with a balanced liquid fertilizer diluted by half. Fertilize every 6-8 weeks in fall and winter.

Light

Place your Philodendron ilsemanii in bright light, but not in direct sunlight.

Huse plant light

Pruning

  • Prune off any dead, damaged, or old trailing stems to keep plant tidy and encourage new growth
  • Use sterile shears and cut back to just above a node
  • Prune in early spring before growing period
  • Pinch off stems to prevent leggy appearance and excess length

Repotting

  • Repot every 2-3 years in early spring
  • Move to a pot only 1-2 inches larger to prevent staying wet
  • Carefully remove rootball and loosen roots before repotting
  • Replace 25% of soil with fresh, sterile potting mix

Propagation

Propagate new philodendron ilsemanii plants from stem cuttings in spring or summer.

  • Take 4-6 inch cuttings and remove lower leaves.
  • Place in water or moist soil.
  • Maintain high humidity.
  • New roots and growth will emerge in 3-8 weeks.

Common Problems & Solutions

Philodendron ilsemanii quick troubleshooting guide

Leaf spots

  • Fungal disease encouraged by excess moisture
  • Improve air circulation and water only when partially dry

Leggy growth

  • Indicates insufficient sunlight; move closer to a bright window

Leaf drop

  • Due to incorrect watering, low humidity, or drafts; assess care routine and environment

Bacterial blight

  • Angular water-soaked spots on leaves
  • Can spread rapidly in high humidity
  • Improve air flow and reduce watering frequency

Sunburn

  • Crispy brown leaf edges from too much direct sun
  • Move plant further away from windows and provide shade
  • Root rot if overwatered for prolonged periods. Allow soil to dry out between waterings
  • Pests like mealybugs, aphids, scale. See further details below.

Pest Control

Mealybugs

  • Apply insecticidal soap spray or neem oil every 3 days for 2 weeks
  • Q-tip cotton swabs dipped in alcohol to remove visible bugs
  • Sprinkle soil with diatomaceous earth to kill emerging nymphs

Aphids

  • Blast with water to dislodge from foliage
  • Apply horticultural oil or insecticidal soap treatment
  • Encourage predators like ladybugs which feed on aphids

Fungus gnats

Disease Prevention

Bacterial blight

  • Provide good air circulation and space pots apart
  • Keep leaves dry and avoid overhead watering
  • Sanitize tools between plants with bleach solution

Botrytis blight

  • Improve air flow around plants
  • Remove affected plant parts promptly
  • Avoid wetting foliage when watering

Environmental Solutions

Insufficient light

  • Identify brighter window for placement
  • Rotate pot periodically for even sun exposure
  • Install grow lights to supplement natural light

Dry air

  • Mist foliage frequently to increase humidity
  • Use a humidifier nearby raising moisture levels
  • Position pot above pebble tray filled with water

FAQ

What type of Philodendron is ilsemanii?

A vining, evergreen tropical plant suitable as a hanging basket or climbing houseplant. Features deeply cut lobed leaves.

Why are my leaves turning yellow?

Overwatering causes leaves to turn yellow and then brown. Allow more time between waterings.

Should I mist my Philodendron ilsemanii?

Yes, misting raises humidity levels these tropical plants prefer. Just be cautious of promoting diseases.

When should I repot this plant?

Repot every 2-3 years in the spring when roots have filled container. Move only one size larger pot to avoid staying wet.

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