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Fertilising guide

How to fertilise Petiole Sundew (Drosera petiolaris)— schedule & NPK

Also called Petiole sundew, Woolly sundew.

More about petiole sundew

About Petiole Sundew

Drosera petiolaris · also called Petiole sundew, Woolly sundew · tropical

Drosera petiolaris is the type species of the petiolaris complex, native to seasonally flooded grasslands and floodplains across the Northern Territory and far north Queensland, Australia. It is a warm-tropical carnivorous plant adapted to a strongly seasonal monsoon climate — requiring a hot, wet growing season followed by a distinctly drier, still-warm rest period. The single most important care fact is that it absolutely cannot tolerate cold: temperatures below 15 °C will cause dormancy failure and death. Drosera is not listed as toxic to cats or dogs by the ASPCA and is considered non-toxic to pets.

Growth habit: Deciduous, rosette-forming perennial with erect, long-petioled leaves; the lamina is covered in red, mucilage-tipped glands; forms a compact ground-level rosette.

What fertiliser petiole sundew actually wants — and why

Petiole Sundew is an easy, light foliage feeder — a half-strength balanced liquid feed through the growing months keeps it green without forcing weak, sappy growth.

A balanced general houseplant feed (roughly even N-P-K) is exactly right — it is grown for foliage, so steady, moderate nitrogen for healthy leaves is the goal, not a bloom or root 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 petiole sundew: 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 petiole sundew, 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 petiole sundew:

Feed by placing small live or freeze-dried insects on active leaves, 3–6 times during the growing season only; do not feed during dormancy. Treat that as sparingly through the growing season between spring through early autumn (roughly March to September); ease off in autumn and stop entirely in the low light of winter.

The dormant-season rule matters more than the exact interval: skip feeding entirely when petiole sundew 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 petiole sundew

Half strength is the safe default for petiole sundew — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.

Feeding always goes onto already-damp soil, never dry roots — water petiole sundew first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the petiole sundew watering schedule.

Signs you are over-feeding petiole sundew

Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for petiole sundew:

Signs you are under-feeding petiole sundew

If the symptoms point at watering, light or roots rather than nutrition, the full petiole sundew care brief covers soil, humidity and the common problems for this species.

Flushing and leaching the salts

Flush the pot of petiole sundew with plain water until it runs freely from the base every couple of months in the feeding season — it washes out the fertiliser salts that cause brown tips.

Organic vs synthetic feeds for petiole sundew

Organic options

A diluted seaweed or worm-casting feed, or fish emulsion if you can tolerate the smell indoors. UK: Westland or Baby Bio Organic, dilute seaweed; US: Espoma Indoor! or Neptune's Harvest fish & seaweed. Slow, gentle and hard to overdo.

Synthetic / liquid feeds

A general-purpose houseplant liquid at half strength — UK: Baby Bio, Westland Houseplant Feed or Phostrogen; US: Miracle-Gro Indoor Plant Food or Schultz. Convenient and fast-acting; the only risk is overdoing it.

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 petiole sundew — frequently asked questions

What fertiliser does petiole sundew need?

A balanced general houseplant feed (roughly even N-P-K) is exactly right — it is grown for foliage, so steady, moderate nitrogen for healthy leaves is the goal, not a bloom or root formula. Petiole Sundew is an easy, light foliage feeder — a half-strength balanced liquid feed through the growing months keeps it green without forcing weak, sappy growth.

How often should I feed petiole sundew?

Feed by placing small live or freeze-dried insects on active leaves, 3–6 times during the growing season only; do not feed during dormancy. Feed by placing small live or freeze-dried insects on active leaves, 3–6 times during the growing season only; do not feed during dormancy. Treat that as sparingly through the growing season between spring through early autumn (roughly March to September); ease off in autumn and stop entirely in the low light of winter.

What strength of feed for petiole sundew?

Half strength is the safe default for petiole sundew — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.

What does over-feeding petiole sundew look like?

Brown, crispy leaf tips and edges with no sign of underwatering. A white, crusty salt deposit on the soil surface or pot rim. Weak, pale, stretched new growth that flops. Lower leaves yellow and drop while the soil is correctly watered. Feeding petiole sundew year-round on a fixed schedule, including dark winter months, is the most common mistake — it cannot use the nutrients in low light and the surplus simply burns the roots and crusts the soil.

Should I flush the soil of petiole sundew?

Flush the pot of petiole sundew with plain water until it runs freely from the base every couple of months in the feeding season — it washes out the fertiliser salts that cause brown tips.

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