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Fertilising guide

How to fertilise Red Kohleria (Kohleria eriantha)— schedule & NPK

Also called Red Kohleria, Woolly Kohleria, Tree Gloxinia.

More about red kohleria

About Red Kohleria

Kohleria eriantha · also called Red Kohleria, Woolly Kohleria · tropical

Kohleria eriantha is a rhizomatous perennial in the Gesneriaceae family, native to Colombia, producing erect, velvety stems and brilliant orange-red tubular flowers spotted with yellow on the lower lobes. It thrives as a houseplant or conservatory specimen in bright filtered light with high humidity, and its underground rhizomes allow it to survive periods of dryness and facilitate easy propagation. The most important care fact is to never splash water on the densely hairy leaves, which trap moisture and develop rot patches or botrytis. Kohleria is not individually listed by the ASPCA; treat with caution around pets.

Growth habit: Bushy, upright rhizomatous perennial with densely hairy, narrowly ovate leaves edged in red hairs and clusters of nodding, tubular orange-red flowers.

What fertiliser red kohleria actually wants — and why

Red Kohleria 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 kohleria: 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 kohleria, 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 kohleria:

Feed every 2–3 weeks during spring and summer with a high-potassium liquid fertiliser (such as tomato feed) to encourage prolific flowering; withhold all feed during the winter rest period. 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 kohleria 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 kohleria

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

Signs you are over-feeding red kohleria

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

Signs you are under-feeding red kohleria

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

Flushing and leaching the salts

Flush the pot of red kohleria 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 kohleria

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 kohleria — frequently asked questions

What fertiliser does red kohleria 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 Kohleria 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 kohleria?

Feed every 2–3 weeks during spring and summer with a high-potassium liquid fertiliser (such as tomato feed) to encourage prolific flowering; withhold all feed during the winter rest period. Feed every 2–3 weeks during spring and summer with a high-potassium liquid fertiliser (such as tomato feed) to encourage prolific flowering; withhold all feed during the winter rest period. 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 kohleria?

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

What does over-feeding red kohleria 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 kohleria 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 kohleria?

Flush the pot of red kohleria 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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