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Fertilising guide

How to fertilise Big Blue Lilyturf (Liriope muscari 'Big Blue')— schedule & NPK

Also called Lilyturf, Monkey Grass, Border Grass.

More about big blue lilyturf

About Big Blue Lilyturf

Liriope muscari 'Big Blue' · also called Lilyturf, Monkey Grass · houseplant

Big Blue Lilyturf is a clump-forming grass-like perennial with arching dark green strap leaves and violet-blue flower spikes in late summer. Indoors it thrives in bright indirect to medium light with consistent moisture. It contains steroidal saponins and is toxic to dogs and cats.

Growth habit: Clump-forming evergreen perennial

Watch for — Leaf tip burn: Usually caused by fluoride in tap water or low humidity. Use filtered water and raise humidity to resolve.

What fertiliser big blue lilyturf actually wants — and why

Big Blue Lilyturf 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 big blue lilyturf: 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 big blue lilyturf, 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 big blue lilyturf:

Feed monthly with a balanced liquid fertiliser diluted to half strength during spring and summer. Withhold fertiliser from October to February when growth slows. 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 big blue lilyturf 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 big blue lilyturf

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

Signs you are over-feeding big blue lilyturf

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

Signs you are under-feeding big blue lilyturf

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

Flushing and leaching the salts

Flush the pot of big blue lilyturf 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 big blue lilyturf

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 big blue lilyturf — frequently asked questions

What fertiliser does big blue lilyturf 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. Big Blue Lilyturf 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 big blue lilyturf?

Feed monthly with a balanced liquid fertiliser diluted to half strength during spring and summer. Withhold fertiliser from October to February when growth slows. Feed monthly with a balanced liquid fertiliser diluted to half strength during spring and summer. Withhold fertiliser from October to February when growth slows. 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 big blue lilyturf?

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

What does over-feeding big blue lilyturf 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 big blue lilyturf 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 big blue lilyturf?

Flush the pot of big blue lilyturf 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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