Fertilising guide

How to fertilise Begonia 'Pin Up Flame' (Begonia × tuberhybrida 'Pin Up Flame')— schedule & NPK

Also called pin up flame begonia, bicolor tuberous begonia.

More about begonia 'pin up flame'

About Begonia 'Pin Up Flame'

Begonia × tuberhybrida 'Pin Up Flame' · also called pin up flame begonia, bicolor tuberous begonia · flowering

Begonia 'Pin Up Flame' is a tuberous begonia with large single flowers in creamy yellow boldly edged in fiery orange-red, an eye-catching bicolour that holds an RHS Award of Garden Merit. Grown as a half-hardy annual or lifted tuber, it flowers all summer in partial shade in moist, free-draining soil and is stored dry over winter.

Growth habit: Bushy, mounding tuberous begonia with brittle, succulent, upright stems; compact and well branched, good for beds, pots and patio displays.

What fertiliser begonia 'pin up flame' actually wants — and why

Begonia 'Pin Up Flame' is a heavy-blooming flower with a big appetite — a regular high-potash feed through the season is what drives a long, dense display.

A high-potassium ("high-potash") flowering feed — tomato-style or a dedicated bloom/rose feed. Potassium powers flowering; a high-nitrogen feed gives you a leafy plant with disappointing bloom.

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 begonia 'pin up flame': 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 begonia 'pin up flame', 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 begonia 'pin up flame':

Feed every 1-2 weeks in summer with a high-potash liquid feed such as a tomato fertiliser to keep the bicolour flowers coming. Use balanced feed early in the season and switch to high-potash as buds form; stop feeding as growth dies back. For a hungry bloomer that means feeding regularly — every 1-2 weeks — right through flowering across the main season (spring through early autumn), tapering as blooming ends.

The dormant-season rule matters more than the exact interval: skip feeding entirely when begonia 'pin up flame' 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 begonia 'pin up flame'

Follow the flowering-feed label rate for begonia 'pin up flame', or half strength if feeding very frequently. These plants genuinely use the nutrients — under-feeding shows up fast as a thin display.

Feeding always goes onto already-damp soil, never dry roots — water begonia 'pin up flame' first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the begonia 'pin up flame' watering schedule.

Signs you are over-feeding begonia 'pin up flame'

Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for begonia 'pin up flame':

Lots of lush leaves but few flowers (too much nitrogen).
Scorched leaf edges and salt crust from too-strong or too-frequent feeds.
Soft, sappy growth prone to aphids and mildew.

Signs you are under-feeding begonia 'pin up flame'

Sparse, small, short-lived flowers and pale foliage.
A tired plant that stops blooming early in the season.
Weak growth and poor repeat-flowering after the first flush.

If the symptoms point at watering, light or roots rather than nutrition, the full begonia 'pin up flame' care brief covers soil, humidity and the common problems for this species.

Flushing and leaching the salts

Container-grown begonia 'pin up flame' accumulates feed salts fast with frequent feeding — water until it drains each time and flush pots with plain water every few weeks to prevent scorch.

Organic vs synthetic feeds for begonia 'pin up flame'

Organic options

A liquid comfrey or seaweed feed (naturally potassium-rich) plus compost or well-rotted manure as a mulch. UK: comfrey feed, organic Tomorite, or rose feed; US: Espoma Rose-tone or Neptune's Harvest. Feeds and improves soil.

Synthetic / liquid feeds

A high-potash flowering feed on a regular cadence — UK: Tomorite (Levington), Phostrogen or a specialist rose feed; US: Miracle-Gro Bloom Booster or a rose food. Fast, reliable bloom response.

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 begonia 'pin up flame' — frequently asked questions

What fertiliser does begonia 'pin up flame' need?

A high-potassium ("high-potash") flowering feed — tomato-style or a dedicated bloom/rose feed. Potassium powers flowering; a high-nitrogen feed gives you a leafy plant with disappointing bloom. Begonia 'Pin Up Flame' is a heavy-blooming flower with a big appetite — a regular high-potash feed through the season is what drives a long, dense display.

How often should I feed begonia 'pin up flame'?

Feed every 1-2 weeks in summer with a high-potash liquid feed such as a tomato fertiliser to keep the bicolour flowers coming. Use balanced feed early in the season and switch to high-potash as buds form; stop feeding as growth dies back. Feed every 1-2 weeks in summer with a high-potash liquid feed such as a tomato fertiliser to keep the bicolour flowers coming. Use balanced feed early in the season and switch to high-potash as buds form; stop feeding as growth dies back. For a hungry bloomer that means feeding regularly — every 1-2 weeks — right through flowering across the main season (spring through early autumn), tapering as blooming ends.

What strength of feed for begonia 'pin up flame'?

What does over-feeding begonia 'pin up flame' look like?

Lots of lush leaves but few flowers (too much nitrogen). Scorched leaf edges and salt crust from too-strong or too-frequent feeds. Soft, sappy growth prone to aphids and mildew. Using a high-nitrogen general feed on begonia 'pin up flame' is the headline mistake — you grow a big leafy plant with few flowers. The second is simply under-feeding a genuinely hungry bloomer and getting a sparse, short display.

Should I flush the soil of begonia 'pin up flame'?