Fertilising guide
How to fertilise Scharff's Begonia (Begonia scharffiana)— schedule & NPK
Also called Scharff's begonia, Hairy begonia.
More about scharff's begonia
About Scharff's Begonia
Begonia scharffiana · also called Scharff's begonia, Hairy begonia · houseplant
Begonia scharffiana is a cane-type begonia from Brazil with distinctive olive-green leaves covered in soft white hairs and bearing clusters of white to pale-pink flowers. It is a robust, fast-growing species that tolerates typical indoor conditions better than many begonias, making it a good choice for beginners. The most important care fact is to ensure strong, indirect light; without adequate brightness it becomes leggy and fails to flower reliably. This plant is toxic to cats and dogs.
Growth habit: Upright, cane-forming perennial with branching stems reaching toward the light.
What fertiliser scharff's begonia actually wants — and why
Scharff's Begonia 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 scharff's begonia: 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 scharff's begonia, 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 scharff's begonia:
Feed fortnightly with a balanced liquid fertiliser at half-strength from March to September; switch to a low-nitrogen, high-potassium feed when flower buds form to encourage blooming. 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 scharff's begonia 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 scharff's begonia
Half strength is the safe default for scharff's begonia — 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 scharff's begonia first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the scharff's begonia watering schedule.
Signs you are over-feeding scharff's begonia
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for scharff's begonia:
- 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.
Signs you are under-feeding scharff's begonia
- Uniformly pale or yellow-green leaves, oldest first.
- Noticeably small new leaves and stalled growth in good light and season.
- A generally tired, lacklustre look despite correct watering and light.
If the symptoms point at watering, light or roots rather than nutrition, the full scharff's begonia care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of scharff's begonia 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 scharff's begonia
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 scharff's begonia — frequently asked questions
What fertiliser does scharff's begonia 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. Scharff's Begonia 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 scharff's begonia?
Feed fortnightly with a balanced liquid fertiliser at half-strength from March to September; switch to a low-nitrogen, high-potassium feed when flower buds form to encourage blooming. Feed fortnightly with a balanced liquid fertiliser at half-strength from March to September; switch to a low-nitrogen, high-potassium feed when flower buds form to encourage blooming. 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 scharff's begonia?
Half strength is the safe default for scharff's begonia — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding scharff's begonia 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 scharff's begonia 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 scharff's begonia?
Flush the pot of scharff's begonia 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.
Keep reading
- Scharff's Begonia care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water scharff's begonia — 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 roller jovibarba
- How to fertilise hairy jovibarba
- How to fertilise navelwort
- All 10153 fertilising guides in the Growli library