Fertilising guide
How to fertilise Philodendron 'Dean McDowell' (Philodendron 'Dean McDowell' (P. gloriosum × P. pastazanum))— schedule & NPK
Also called Dean McDowell Philodendron, Philodendron McDowell, McDowell Philodendron.
More about philodendron 'dean mcdowell'
About Philodendron 'Dean McDowell'
Philodendron 'Dean McDowell' (P. gloriosum × P. pastazanum) · also called Dean McDowell Philodendron, Philodendron McDowell · tropical
Philodendron 'Dean McDowell' is a rare aroid hybrid (gloriosum x pastazanum) prized for huge, velvety, white-veined heart-shaped leaves on a creeping rhizome. Give bright indirect light, a chunky moist aroid mix, warmth and high humidity. It is toxic: the ASPCA lists Philodendron as toxic to cats and dogs.
Growth habit: Terrestrial, creeping rhizomatous perennial that grows horizontally rather than upward. The rhizome crawls along the soil surface, sending up oversized heart-shaped leaves (pink when new, maturing deep green with bold pale veins) along its length.
Watch for — Pale leaves or scorched patches: Direct sun bleaches and burns the velvety surface. Filter strong light with a sheer curtain or move back from the window.
What fertiliser philodendron 'dean mcdowell' actually wants — and why
Philodendron 'Dean McDowell' is a genuinely hungry tropical — in bright warmth it pushes growth fast and rewards a regular half-strength balanced feed all season.
A balanced liquid feed (even N-P-K) or a slightly nitrogen-leaning foliage feed — this is a big-leaved foliage plant putting on real size, so it wants steady nitrogen for lush leaves, not a bloom formula.
For the language behind the three numbers on the bottle — what nitrogen, phosphorus and potassium each do — see the NPK ratio explained entry. The short version for philodendron 'dean mcdowell': match the feed to the job the plant is doing right now, not to a generic “plant food” on the shelf.
How often to feed philodendron 'dean mcdowell', and which months
Feeding only earns its keep while the plant is in active growth and can use the nutrients — pour feed into a dormant or low-light plant and it simply builds up as root-burning salt. For philodendron 'dean mcdowell':
Feed every 4-6 weeks through spring and summer with a balanced, diluted (half-strength) houseplant fertiliser. Pause in autumn and winter. This slow grower is sensitive to salt build-up, so flush the substrate periodically and avoid overfeeding. For a fast grower like this that means feeding regularly — about every 4-6 weeks — right through spring through early autumn (roughly March to September), tapering off only as light drops in autumn.
The dormant-season rule matters more than the exact interval: skip feeding entirely when philodendron 'dean mcdowell' is resting. For the wider context on indoor feeding rhythms across the seasons, the houseplant fertiliser schedule walks through the year month by month.
What strength to mix for philodendron 'dean mcdowell'
Half strength every feed is the sweet spot for philodendron 'dean mcdowell': frequent enough to fuel fast growth, dilute enough that it never scorches even when you feed often.
Feeding always goes onto already-damp soil, never dry roots — water philodendron 'dean mcdowell' first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the philodendron 'dean mcdowell' watering schedule.
Signs you are over-feeding philodendron 'dean mcdowell'
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for philodendron 'dean mcdowell':
- Brown, scorched leaf tips and margins despite correct watering.
- A white salt crust on the soil or around the pot edge.
- Sudden leaf yellowing and drop shortly after a strong feed.
- Soft, weak, over-stretched growth that cannot support itself.
Signs you are under-feeding philodendron 'dean mcdowell'
- New leaves coming in noticeably smaller than older ones.
- Pale, yellow-green older leaves and slow growth through peak summer.
- A general loss of vigour and gloss in a plant that should be racing away.
If the symptoms point at watering, light or roots rather than nutrition, the full philodendron 'dean mcdowell' care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Because you feed often, salts accumulate faster — flush the pot of philodendron 'dean mcdowell' with plain water until it drains freely roughly every month through the feeding season to keep the root zone clean.
Organic vs synthetic feeds for philodendron 'dean mcdowell'
Organic options
A diluted seaweed or fish-and-seaweed feed plus a yearly top-dress of worm castings supports fast growth without burn risk. UK: Westland seaweed or Baby Bio Organic; US: Neptune's Harvest or Espoma Indoor!.
Synthetic / liquid feeds
A balanced houseplant liquid at half strength applied frequently — UK: Baby Bio, Phostrogen or Westland Houseplant Feed; US: Miracle-Gro Indoor Plant Food or Dyna-Gro Foliage-Pro for steady leafy growth.
Brand names are examples, not endorsements, and UK and US ranges differ — check the label’s own NPK and dilution rate, since formulations change.
Fertilising philodendron 'dean mcdowell' — frequently asked questions
What fertiliser does philodendron 'dean mcdowell' need?
A balanced liquid feed (even N-P-K) or a slightly nitrogen-leaning foliage feed — this is a big-leaved foliage plant putting on real size, so it wants steady nitrogen for lush leaves, not a bloom formula. Philodendron 'Dean McDowell' is a genuinely hungry tropical — in bright warmth it pushes growth fast and rewards a regular half-strength balanced feed all season.
How often should I feed philodendron 'dean mcdowell'?
Feed every 4-6 weeks through spring and summer with a balanced, diluted (half-strength) houseplant fertiliser. Pause in autumn and winter. This slow grower is sensitive to salt build-up, so flush the substrate periodically and avoid overfeeding. Feed every 4-6 weeks through spring and summer with a balanced, diluted (half-strength) houseplant fertiliser. Pause in autumn and winter. This slow grower is sensitive to salt build-up, so flush the substrate periodically and avoid overfeeding. For a fast grower like this that means feeding regularly — about every 4-6 weeks — right through spring through early autumn (roughly March to September), tapering off only as light drops in autumn.
What strength of feed for philodendron 'dean mcdowell'?
Half strength every feed is the sweet spot for philodendron 'dean mcdowell': frequent enough to fuel fast growth, dilute enough that it never scorches even when you feed often.
What does over-feeding philodendron 'dean mcdowell' look like?
Brown, scorched leaf tips and margins despite correct watering. A white salt crust on the soil or around the pot edge. Sudden leaf yellowing and drop shortly after a strong feed. Soft, weak, over-stretched growth that cannot support itself. The mistake here is the opposite of most houseplants: under-feeding a fast tropical in peak season starves it, leaving small, pale new leaves and slow growth — but full-strength doses still burn it, so feed often and weak, not occasionally and strong.
Should I flush the soil of philodendron 'dean mcdowell'?
Because you feed often, salts accumulate faster — flush the pot of philodendron 'dean mcdowell' with plain water until it drains freely roughly every month through the feeding season to keep the root zone clean.
Keep reading
- Philodendron 'Dean McDowell' care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water philodendron 'dean mcdowell' — the watering schedule
- The houseplant fertiliser schedule — feeding through the year
- NPK ratio explained — what the three numbers on the bottle mean
- How to fertilise monstera
- How to fertilise pothos
- How to fertilise fiddle leaf fig
- All 609 fertilising guides in the Growli library