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Fertilising guide

How to fertilise White Campion (Silene latifolia)— schedule & NPK

Also called White Campion, White Cockle, Evening Lychnis.

More about white campion

About White Campion

Silene latifolia · also called White Campion, White Cockle · flowering

Silene latifolia is a dioecious biennial or short-lived perennial native to disturbed ground, roadsides, and arable margins across Europe and introduced across North America. Its white, five-petalled flowers open in the evening and are fragrant, attracting moths and other nocturnal pollinators. The most critical care note is that it resents waterlogging, especially in winter, and needs sharp drainage to persist. As with other Silene species it contains saponins and is treated as mildly toxic to pets in the absence of ASPCA listing.

Growth habit: Upright, biennial or short-lived perennial with sticky, hairy stems and opposite elliptic leaves; separate male and female plants needed for seed set.

What fertiliser white campion actually wants — and why

White Campion 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 white campion: 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 white campion, 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 white campion:

No routine feeding required on typical garden soils; on very poor sandy soils a light balanced feed in spring can support flowering. 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 white campion 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 white campion

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

Signs you are over-feeding white campion

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

Signs you are under-feeding white campion

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

Flushing and leaching the salts

Flush the pot of white campion 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 white campion

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 white campion — frequently asked questions

What fertiliser does white campion 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. White Campion 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 white campion?

No routine feeding required on typical garden soils; on very poor sandy soils a light balanced feed in spring can support flowering. No routine feeding required on typical garden soils; on very poor sandy soils a light balanced feed in spring can support flowering. 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 white campion?

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

What does over-feeding white campion 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 white campion 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 white campion?

Flush the pot of white campion 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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