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Fertilising guide

How to fertilise Small Teasel (Dipsacus pilosus)— schedule & NPK

Also called Small Teasel, Lesser Teasel.

More about small teasel

About Small Teasel

Dipsacus pilosus · also called Small Teasel, Lesser Teasel · flowering

Small teasel is a British and European native biennial found along the shaded edges of damp woodland, hedgerows, and stream banks on calcareous soils. Unlike its larger relative, it prefers partial shade and produces small, white, softly globose flowerheads on stems reaching 1–1.5 m in its second year. It is an excellent choice for naturalising in a wildlife or woodland-edge garden, and the key care note is that it requires consistently moist, neutral to alkaline soil and some overhead shade to thrive. No significant toxicity to dogs or cats has been reported.

Growth habit: Biennial; basal rosette in year one, upright branched stem with spherical flowerheads in year two, dying after setting seed.

What fertiliser small teasel actually wants — and why

Small Teasel 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 small teasel: 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 small teasel, 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 small teasel:

No regular feeding required; excessive fertility on shaded sites promotes lush, weak growth. 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 small teasel 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 small teasel

Half strength is the safe default for small teasel — 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 small teasel first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the small teasel watering schedule.

Signs you are over-feeding small teasel

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

Signs you are under-feeding small teasel

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

Flushing and leaching the salts

Flush the pot of small teasel 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 small teasel

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 small teasel — frequently asked questions

What fertiliser does small teasel 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. Small Teasel 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 small teasel?

No regular feeding required; excessive fertility on shaded sites promotes lush, weak growth. No regular feeding required; excessive fertility on shaded sites promotes lush, weak growth. 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 small teasel?

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

What does over-feeding small teasel 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 small teasel 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 small teasel?

Flush the pot of small teasel 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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