Fertilising guide
How to fertilise Caucasian Lily (Lilium monadelphum)— schedule & NPK
Also called Caucasian Lily, Szovits Lily, Yellow Caucasian Lily.
More about caucasian lily
About Caucasian Lily
Lilium monadelphum · also called Caucasian Lily, Szovits Lily · flowering
Lilium monadelphum is a stately, tall true lily from the subalpine meadows and forest margins of the Caucasus and north-eastern Turkey, producing large, fragrant, pendant bells of pale yellow to golden yellow with a delicate speckled interior and reflexed petal tips in early to midsummer. It is notably more tolerant of shade, chalk, and clay than most lilies, making it one of the most garden-worthy and adaptable species for UK conditions. Severely toxic to cats — all Lilium species cause acute renal failure in cats.
Growth habit: Tall, stately bulbous perennial with lance-shaped scattered leaves, a sturdy central stem, and a terminal raceme of 5–30 pendant, fragrant bell-shaped flowers with recurving petal tips; stem-rooting
What fertiliser caucasian lily actually wants — and why
Caucasian Lily feeds for next year, not this one — the critical window is after flowering, while the leaves are still green and recharging the bulb.
A low-nitrogen, potassium- and phosphorus-leaning bulb fertiliser (something like 5-10-10) or bonemeal at planting. High nitrogen grows floppy leaves and rots stored bulbs.
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 caucasian lily: 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 caucasian lily, 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 caucasian lily:
Apply a balanced, slow-release bulb fertiliser in early spring as stems emerge. Supplement with a high-potassium liquid feed fortnightly from bud formation until flowering ends, to rebuild the bulb's energy reserves. Avoid high-nitrogen fertilisers which produce excessive, disease-prone leafy growth. The rhythm: a bulb feed at planting, a light feed as leaves emerge, and — most important — a potassium feed straight after flowering while the foliage is still green and feeding the bulb. Never cut the leaves off early.
The dormant-season rule matters more than the exact interval: skip feeding entirely when caucasian lily 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 caucasian lily
Use the bulb-feed label rate for caucasian lily; the timing (post-bloom, leaves still green) does far more for next year's display than the concentration.
Feeding always goes onto already-damp soil, never dry roots — water caucasian lily first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the caucasian lily watering schedule.
Signs you are over-feeding caucasian lily
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for caucasian lily:
- Tall, floppy, soft leaves that flop over (too much nitrogen).
- Soft or rotting bulbs lifted at the end of the season.
- Lush foliage but few or poor flowers.
Signs you are under-feeding caucasian lily
- Progressively fewer or smaller flowers year on year ("going blind").
- Small, weak bulbs and thin foliage.
- Bulbs that fail to come back at all after a few seasons.
If the symptoms point at watering, light or roots rather than nutrition, the full caucasian lily care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Bulbs are not container-flushed like houseplants; the equivalent is not over-feeding and lifting/dividing congested clumps of caucasian lily every few years so they are not competing for nutrients.
Organic vs synthetic feeds for caucasian lily
Organic options
Bonemeal worked in at planting plus a mulch of garden compost or well-rotted leaf-mould is the traditional, reliable approach for caucasian lily. UK: blood, fish & bone or Westland Bulb Food; US: Espoma Bulb-tone or bonemeal.
Synthetic / liquid feeds
A proprietary bulb fertiliser at planting and a high-potash liquid (tomato feed) after flowering — UK: Westland Bulb Food then Tomorite; US: Miracle-Gro Shake 'n Feed Bulb or a bloom booster post-flower.
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 caucasian lily — frequently asked questions
What fertiliser does caucasian lily need?
A low-nitrogen, potassium- and phosphorus-leaning bulb fertiliser (something like 5-10-10) or bonemeal at planting. High nitrogen grows floppy leaves and rots stored bulbs. Caucasian Lily feeds for next year, not this one — the critical window is after flowering, while the leaves are still green and recharging the bulb.
How often should I feed caucasian lily?
Apply a balanced, slow-release bulb fertiliser in early spring as stems emerge. Supplement with a high-potassium liquid feed fortnightly from bud formation until flowering ends, to rebuild the bulb's energy reserves. Avoid high-nitrogen fertilisers which produce excessive, disease-prone leafy growth. Apply a balanced, slow-release bulb fertiliser in early spring as stems emerge. Supplement with a high-potassium liquid feed fortnightly from bud formation until flowering ends, to rebuild the bulb's energy reserves. Avoid high-nitrogen fertilisers which produce excessive, disease-prone leafy growth. The rhythm: a bulb feed at planting, a light feed as leaves emerge, and — most important — a potassium feed straight after flowering while the foliage is still green and feeding the bulb. Never cut the leaves off early.
What strength of feed for caucasian lily?
Use the bulb-feed label rate for caucasian lily; the timing (post-bloom, leaves still green) does far more for next year's display than the concentration.
What does over-feeding caucasian lily look like?
Tall, floppy, soft leaves that flop over (too much nitrogen). Soft or rotting bulbs lifted at the end of the season. Lush foliage but few or poor flowers. Cutting or tying off the leaves of caucasian lily as soon as the flowers fade is the great bulb mistake — the bulb recharges through those leaves for weeks afterward, and removing them early means a weak or blind display next year.
Should I flush the soil of caucasian lily?
Bulbs are not container-flushed like houseplants; the equivalent is not over-feeding and lifting/dividing congested clumps of caucasian lily every few years so they are not competing for nutrients.
Keep reading
- Caucasian Lily care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water caucasian lily — 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 deutzia scabra 'plena'
- How to fertilise deutzia x elegantissima 'rosealind'
- How to fertilise philadelphus 'virginal'
- All 10153 fertilising guides in the Growli library