Philodendron Pink Princess

Start here

A Pink Princess is not hard to keep alive. It is hard to keep pink, and those are two different problems with two different answers.

The two mistakes

Leaving it in moderate light and waiting. The plant stays perfectly healthy and slowly stops producing pink. Six months later you have a dark green philodendron. It does not correct itself, and by the time it is obvious you have a long stretch of green stem to cut back through.

Never picking up the secateurs. This is a plant you manage. Unlike a Thai Constellation, its variegation drifts, and the tool for holding it steady is cutting back to a well-marked node. People treat pruning as damage and then lose the pink.

What normal looks like

• Every leaf marked differently. Splashes, blocks, half-and-half, sometimes a whole leaf pink.
• Some leaves with no pink at all between two good ones. Normal variation, not reversion.
• Pink that darkens and dulls slightly as a leaf ages. Older pink is never as bright as new pink.
• Deep wine-red stems and leaf stalks.
• One new leaf at a time from the growing tip, larger once it has something to climb.
• Very little growth between May and September.

Where it comes from

Philodendron erubescens is native to Colombia, growing in humid tropical forest as a hemiepiphyte. It germinates on the forest floor, climbs the nearest trunk using aerial roots, and produces progressively larger leaves as it rises into better light. That habit is why a moss pole makes such a difference indoors, and why a plant left to sprawl stays small.

The Pink Princess is a variegated selection of that species, maintained entirely in cultivation. As with the White Knight, we cannot point you to a documented origin: no reliable date, breeder or location is attached to it in any source we would stand behind. It became widely known during the rare-plant surge of the late 2010s, when prices were extraordinary, and has since become far more affordable as propagation caught up with demand.

Naming, and the Pink Congo warning

The blushing philodendron

Erubescens comes from the Latin erubescere, to redden or blush, describing the wine-red flush on stems, leaf stalks and the undersides of new growth. On a Pink Princess those dark red stems are one of the identifying features and part of what makes the pink read so strongly against them.

Pink Congo, and why it matters

Around 2019, plants marketed as Pink Congo appeared widely, showing large areas of solid pink foliage at prices well below a Pink Princess. The pink was not variegation. It was induced by treating the plants with chemicals during production, and within six to twelve months the affected leaves reverted to ordinary green permanently.

The trade has largely moved on, but the episode is worth knowing about because it explains why experienced buyers look for irregular marking rather than lots of pink. Irregularity is the evidence that the variegation is real.

How the pink works

Two tissues, one stem

A chimera is a plant whose growing tip carries two distinct cell lines layered together. One makes chlorophyll normally. The other carries a mutation preventing it, and in this cultivar that tissue shows as pink rather than white because of anthocyanin pigments present in the plant.

As the growing tip divides and pushes out each new leaf, whichever cell line ends up where determines the pattern. There is no sequence being followed. Every leaf is a fresh roll of the dice, which is why nobody, including the grower, can tell you what the next one will look like.

Pink tissue is a passenger

Pink sections contribute no energy and still cost water and structure to build. Three consequences follow, and all three get misread as problems:

• It grows slowly, because there is less working leaf than the plant's size suggests.
• It needs more light than a plain philodendron, since the green sections are doing the work of a whole plant.
• A fully pink leaf is a liability. Spectacular, and it will never pay for itself. The plant supports it from elsewhere until it browns off.

Reversion

The opposite failure, and the common one. Green tissue photosynthesises, so it grows faster, and a reverting stem progressively out-competes the variegated growth until the whole plant is green. It does not recover on its own.

Low light drives it. Under insufficient light the plant is under pressure to maximise photosynthetic capacity, and green growth wins. Catching it early and cutting back to a variegated node is the only reliable response.

Growing it

Light

Bright indirect light for as much of the day as you can manage. In New Zealand a north-facing window is strongest, with the plant slightly back from the glass or behind a sheer curtain. An east-facing window with gentle morning sun works well too.

Direct summer sun is the thing to avoid. Pink tissue has no protection and New Zealand's UV is strong, so sun damage shows on the pink first, as brown papery patches that never recover.

Water

Water when the top few centimetres of mix have dried. Check with a finger, not a schedule.

1. Check first. Push a finger in to the second knuckle. Damp means wait.
2. Water thoroughly at the sink until it runs from the drainage holes.
3. Drain completely, then tip out anything sitting in the cover pot.
4. Wait and check again. Roughly weekly in an Auckland summer, stretching to a fortnight or more in winter.

Heavily variegated plants use water more slowly than green ones, so this one should be watered less often than the rest of your philodendrons rather than on the same round.

Support and climbing

A moss or coir pole is the single change that most improves this plant. As the aerial roots grip a damp pole it switches into climbing mode and starts making progressively larger leaves. Without one it keeps producing modest leaves indefinitely. Tie the stem loosely until the roots take hold, and water down the pole.

Temperature, humidity and mix

Comfortable between 18 and 26 degrees, stalling below 15. Keep it off cold glass on frosty nights and out of direct heat pump flow.

Humidity above 60 percent is ideal. It will live at ordinary indoor humidity but pink edges brown more readily and new leaves unfurl less cleanly in dry air. Group plants, use a bright bathroom, or run a humidifier through winter.

For mix, use roughly equal parts quality indoor potting mix, orchid bark, and pumice or perlite. Standard potting mix alone holds too much water around aroid roots.

Feeding and repotting

A balanced liquid fertiliser at half strength every three to four weeks from October to April, onto damp mix. Stop from May. No fertiliser increases pink, and over-feeding a slow plant builds up salts that damage roots.

Repot every two years or so in spring, one size up only. An oversized pot holds wet mix a slow plant cannot use.

Managing the variegation

This is the part that separates a Pink Princess that still looks like one in three years from a green philodendron with an expensive receipt. It is simple, and the only difficulty is being willing to cut.

1. Read the trend. Look at the last three or four leaves in order. One green leaf between good ones is normal variation. Each leaf having less pink than the one before is reversion.
2. Fix the light first. Cutting without improving conditions just produces more green growth from the new shoot.
3. Find the node. Trace back down the stem to the last leaf with a good balance of pink and green. The node is the slightly swollen band where that leaf and its aerial root emerge.
4. Cut about a centimetre above that node with sterilised secateurs.
5. Keep the cutting. The piece you removed still has leaves and nodes, and can be rooted. Nothing is wasted.

The plant reshoots from a bud at that node, and because the node sits in tissue carrying both cell lines the new growth carries the variegation again. The same cut fixes the opposite problem: a stem producing consecutive all-pink leaves is running out of chlorophyll and needs cutting back to a balanced node before it stalls.

Propagation

The variegation travels only in the tissue that carries it. A cutting taken from a fully green section grows into a fully green plant, permanently. People choose the prettiest leaf, but what matters is the node, because the bud at that node is what becomes the new plant.

Stem cuttings

1. Choose a section with at least one node and a well-variegated leaf. Two nodes is better than one.
2. Cut cleanly about a centimetre below the node with sterilised secateurs.
3. Let the cut callus in the shade for an hour or two.
4. Root in damp sphagnum moss, perlite or water. Sphagnum is the most reliable for aroids.
5. Keep warm, humid and brightly lit. A clear bag or propagation box helps.
6. Expect roots in three to six weeks. Pot into chunky mix once roots are several centimetres long.

Air layering

Slower and safer, because nothing leaves the parent until roots exist. Wrap a well-placed node in damp sphagnum, enclose in cling film secured above and below, keep the moss damp for four to eight weeks, then cut below the new roots and pot up.

Diagnose a problem

Tick everything you can actually see on your plant. The more you tick, the better this gets at separating causes that look alike.

Water problems

Root rot

The most common way a Pink Princess is lost. Because it grows slowly and uses water slowly, a routine that suits faster philodendrons keeps it too wet. Contributing causes are dense mix, an oversized pot, a cover pot holding standing water, and watering to a calendar.

How to identify it

• Several leaves yellowing or drooping at once rather than one old leaf at a time.
• Stem soft, dark or squashy near the mix line.
• Mix still visibly wet more than a week after watering.
• A sour or swampy smell from the pot.
• Roots brown, soft and stringy rather than firm and pale. The definitive test.

How to treat it

1. Remove the plant and wash the old mix off the roots.
2. Cut away every soft brown root back to firm pale tissue with sterilised secateurs.
3. If the stem is soft at the base, cut above the damage into clean firm tissue. A healthy top section can be re-rooted.
4. Let the cuts dry in the shade for a few hours.
5. Repot into fresh chunky mix in a pot sized to the remaining roots.
6. Wait several days before watering, then water sparingly until new growth appears.

If the base is beyond saving, take a cutting from the healthiest well-marked section of stem and root it in sphagnum. A Pink Princess is rarely a total loss while any firm variegated stem remains.

Underwatering

Less dangerous and usually reversible. Leaves go limp, the pot feels light, and the mix pulls away from the sides. Water thoroughly, or soak the pot in a basin for 20 minutes if the mix has gone hydrophobic, then drain fully. Leaves usually firm up within a day.

Light and variegation problems

Reversion to green

The slow one, and the one people notice too late. Each new leaf carries less pink than the one before, eventually emerging solid green, while the plant otherwise looks perfectly healthy.

Improve the light first, then cut back to a node below the last well-marked leaf. See managing the variegation for the method. Cutting without fixing the light simply produces more green growth.

Running out of green

The opposite failure. A run of nearly all-pink leaves is a stem losing the ability to feed itself. Growth slows, then stops, then the stem dies back. The same cut fixes it, and it is worth doing while the stem is still healthy rather than waiting to see whether it recovers, because it will not.

Sun scorch

Direct sun through unshaded glass, most likely November to February, and most likely just after moving a plant somewhere brighter without a transition. Damage appears on pink sections specifically, with sharply defined edges, on the side facing the window, over days rather than months.

Move it back from the glass or add a sheer curtain. Scorched tissue does not repair. When moving a plant into brighter conditions, do it over two weeks in stages.

Pink edges browning

Distinct from scorch and much more common. Pink tissue is structurally weaker than green and dries faster, so heavily marked leaves often brown a little at their pink margins. Consistent watering and better humidity reduce it, but some of it is simply the cost of variegation.

Pests

Treating thrips

1. Isolate the plant immediately, away from every other plant in the house.
2. Rinse the whole plant thoroughly in the shower, paying attention to the furled new leaf and every leaf joint.
3. Treat with Yates Mavrik, adding Grosafe Enspray 99 as a wetting agent. Both are at Mitre 10, Bunnings and garden centres.
4. Repeat every five to seven days for at least four rounds. Eggs are laid inside leaf tissue and survive contact sprays.
5. Keep checking weekly for a month after you think it is over.

Treating spider mites and mealybugs

For mites, isolate, rinse thoroughly and treat with Yates Mavrik or Grosafe Enspray 99 every five to seven days for at least three rounds, then raise humidity. For mealybugs, remove each insect individually with a cotton bud dipped in isopropyl alcohol, then follow with horticultural oil every seven to ten days for three to four rounds, checking around aerial roots and the stem base.

Other issues

Safety and pets

Like the rest of the arum family, Philodendron erubescens contains insoluble calcium oxalate as raphides: needle-shaped crystals held under pressure in the plant tissue. When bitten they are released into the soft tissue of the mouth. The effect is mechanical rather than chemical, which is why it hurts immediately rather than hours later.

Symptoms in cats and dogs

• Pawing at the mouth or rubbing the face along the floor.
• Sudden heavy drooling.
• Head shaking and reluctance to eat.
• Vomiting or diarrhoea if a quantity has been swallowed.

What to do

Remove any remaining plant material from the mouth and offer water, milk or a small amount of food to help flush the crystals through. Symptoms usually settle within a few hours. Contact your vet if drooling persists, if there is swelling around the mouth or throat, or if breathing seems affected.

For people

The sap irritates skin and eyes. This matters more with this plant than most, because keeping it well marked involves regular cutting. Wash your hands after pruning or taking cuttings, and wear gloves if you have sensitive skin.

Questions