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Fertilising guide

How to fertilise Wavy Nerine (Nerine undulata)— schedule & NPK

Also called Wavy-petalled Nerine, Pink Nerine, Small Guernsey Lily.

More about wavy nerine

About Wavy Nerine

Nerine undulata · also called Wavy-petalled Nerine, Pink Nerine · flowering

Nerine undulata is a graceful South African bulb producing delicate, wavy-petalled pink flowers on slender stems in autumn. Smaller and more delicate in appearance than N. bowdenii but with a similar autumn blooming season. Suitable for pots or a sheltered garden position in mild UK areas. Toxic to pets due to lycorine alkaloids in the bulb.

Growth habit: Deciduous bulbous perennial with summer dormancy

What fertiliser wavy nerine actually wants — and why

Wavy Nerine 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 wavy nerine: 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 wavy nerine, 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 wavy nerine:

Apply a high-potassium liquid feed (half-strength tomato fertiliser) monthly from when foliage is established in autumn until leaves start to yellow in late spring. Avoid any feeding during summer dormancy. Treat that as monthly 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 wavy nerine 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 wavy nerine

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

Signs you are over-feeding wavy nerine

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

Signs you are under-feeding wavy nerine

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

Flushing and leaching the salts

Flush the pot of wavy nerine 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 wavy nerine

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 wavy nerine — frequently asked questions

What fertiliser does wavy nerine 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. Wavy Nerine 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 wavy nerine?

Apply a high-potassium liquid feed (half-strength tomato fertiliser) monthly from when foliage is established in autumn until leaves start to yellow in late spring. Avoid any feeding during summer dormancy. Apply a high-potassium liquid feed (half-strength tomato fertiliser) monthly from when foliage is established in autumn until leaves start to yellow in late spring. Avoid any feeding during summer dormancy. Treat that as monthly 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 wavy nerine?

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

What does over-feeding wavy nerine 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 wavy nerine 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 wavy nerine?

Flush the pot of wavy nerine 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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