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Fertilising guide

How to fertilise Red morning glory (Ipomoea coccinea)— schedule & NPK

Also called Red morning glory, Scarlet creeper, Redstar, Mexican morning glory.

More about red morning glory

About Red morning glory

Ipomoea coccinea · also called Red morning glory, Scarlet creeper · flowering

Red morning glory is a slender, fast-twining annual vine bearing clusters of small scarlet trumpets with yellow throats that attract hummingbirds. Thrives in full sun on poor-to-average soil and tolerates heat and drought once established. Seeds contain indole alkaloids and are toxic to pets. Can reseed aggressively in warm climates.

Growth habit: Slender annual twining vine

Watch for — Sparse flowering in rich soil: Excess fertility pushes leaf growth at the expense of blooms. This species actually performs better in lean, average soil with minimal fertilising.

What fertiliser red morning glory actually wants — and why

Red morning glory 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 red morning glory: 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 red morning glory, 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 red morning glory:

Apply a low-nitrogen fertiliser (e.g., 5-10-10) once at planting. On poor soils a single midsummer feed may help; over-fertilising depresses bloom production. 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 red morning glory 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 red morning glory

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

Signs you are over-feeding red morning glory

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

Signs you are under-feeding red morning glory

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

Flushing and leaching the salts

Flush the pot of red morning glory 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 red morning glory

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 red morning glory — frequently asked questions

What fertiliser does red morning glory 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. Red morning glory 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 red morning glory?

Apply a low-nitrogen fertiliser (e.g., 5-10-10) once at planting. On poor soils a single midsummer feed may help; over-fertilising depresses bloom production. Apply a low-nitrogen fertiliser (e.g., 5-10-10) once at planting. On poor soils a single midsummer feed may help; over-fertilising depresses bloom production. 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 red morning glory?

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

What does over-feeding red morning glory 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 red morning glory 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 red morning glory?

Flush the pot of red morning glory 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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