Fertilising guide

How to fertilise Tongue of Fire Bean (Phaseolus vulgaris 'Tongue of Fire')— schedule & NPK

Also called Tongue of Fire bean, borlotti bean, speckled shell bean.

More about tongue of fire bean

About Tongue of Fire Bean

Phaseolus vulgaris 'Tongue of Fire' · also called Tongue of Fire bean, borlotti bean · edible

'Tongue of Fire' is an Italian borlotti-type bean grown mainly for its plump, cream-and-red flecked shelling beans, though young pods can be eaten as snaps. Available in bush and semi-runner forms, it needs full sun, warm soil and steady moisture. Beans are shelled fresh or dried for soups and stews.

Growth habit: Bush to semi-runner habit depending on strain; bush forms are compact and self-supporting, semi-runners benefit from short supports or netting.

Watch for — Poor pod set: Excess nitrogen or extreme heat reduces beans. Avoid high-nitrogen feed and water steadily through bloom in hot spells.

What fertiliser tongue of fire bean actually wants — and why

Tongue of Fire Bean feeds in two distinct phases — balanced to build the plant, then high-potassium the moment flowering starts to set and fill a heavy crop.

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 tongue of fire bean: 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 tongue of fire bean, 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 tongue of fire bean:

Light feeder. Compost-enriched soil and the plant's own nitrogen fixation usually suffice; a low-nitrogen or balanced feed at flowering supports pod fill without excess foliage. So: a balanced feed or compost at planting, then a high-potash liquid every 1-2 weeks from first flower through harvest across the main season (spring through early autumn).

The dormant-season rule matters more than the exact interval: skip feeding entirely when tongue of fire bean 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 tongue of fire bean

Follow the crop-feed label rate for tongue of fire bean — these are calibrated for hungry vegetables. Consistency through fruiting matters more than strength; erratic feeding causes problems like blossom-end rot.

Feeding always goes onto already-damp soil, never dry roots — water tongue of fire bean first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the tongue of fire bean watering schedule.

Signs you are over-feeding tongue of fire bean

Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for tongue of fire bean:

Vigorous dark-green leafy growth but few flowers or fruit (excess nitrogen).
Lush foliage hiding the crop; soft growth prone to pests and disease.
Salt crust on the soil and scorched leaf edges in containers.

Signs you are under-feeding tongue of fire bean

Pale, yellowing lower leaves and stunted growth.
Small fruit, poor set, and a quickly exhausted plant.
Blossom-end rot and weak cropping from erratic or insufficient feeding.

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

Flushing and leaching the salts

In containers, fertiliser salts build up fast — water tongue of fire bean thoroughly so excess drains from the base each time, and flush pots with plain water every few weeks to prevent a damaging salt build-up.

Organic vs synthetic feeds for tongue of fire bean

Organic options

Garden compost or well-rotted manure dug in before planting, plus a liquid comfrey or seaweed feed once fruiting starts. UK: comfrey feed or organic Tomorite; US: Espoma Tomato-tone or Neptune's Harvest. Builds soil and feeds in one.

Synthetic / liquid feeds

A balanced feed at planting then a high-potash tomato feed in fruiting — UK: Growmore at planting then Tomorite (Levington) or Phostrogen; US: a balanced 10-10-10 then Miracle-Gro Tomato or a bloom booster.

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 tongue of fire bean — frequently asked questions

What fertiliser does tongue of fire bean need?

Balanced (even N-P-K) at planting for roots and frame, then switch to a high-potassium ("high-potash") tomato-style feed once the first flowers open — potassium is what sizes and ripens fruit, not nitrogen. Tongue of Fire Bean feeds in two distinct phases — balanced to build the plant, then high-potassium the moment flowering starts to set and fill a heavy crop.

How often should I feed tongue of fire bean?

Light feeder. Compost-enriched soil and the plant's own nitrogen fixation usually suffice; a low-nitrogen or balanced feed at flowering supports pod fill without excess foliage. Light feeder. Compost-enriched soil and the plant's own nitrogen fixation usually suffice; a low-nitrogen or balanced feed at flowering supports pod fill without excess foliage. So: a balanced feed or compost at planting, then a high-potash liquid every 1-2 weeks from first flower through harvest across the main season (spring through early autumn).

What strength of feed for tongue of fire bean?

What does over-feeding tongue of fire bean look like?

Vigorous dark-green leafy growth but few flowers or fruit (excess nitrogen). Lush foliage hiding the crop; soft growth prone to pests and disease. Salt crust on the soil and scorched leaf edges in containers. Staying on a high-nitrogen feed once tongue of fire bean starts flowering is the classic error — you get a huge leafy plant and a disappointing crop. Switch to high-potash the moment flowers appear.

Should I flush the soil of tongue of fire bean?