Fertilising guide

How to fertilise Aquadulce Broad Bean (Vicia faba)— schedule & NPK

Also called Fava Bean, Field Bean, Windsor Bean.

More about aquadulce broad bean

About Aquadulce Broad Bean

Vicia faba · also called Fava Bean, Field Bean · edible

Aquadulce is the premier autumn-sowing broad bean variety, producing long, robust pods with large, sweet beans. Exceptionally winter-hardy, it is sown in late autumn in the UK for an early summer harvest. Causes 'favism' in genetically susceptible people. ASPCA does not list Vicia faba as toxic to cats and dogs.

Growth habit: Upright, stout-stemmed annual

What fertiliser aquadulce broad bean actually wants — and why

Aquadulce Broad 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 aquadulce broad 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 aquadulce broad 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 aquadulce broad bean:

Minimal fertiliser needed — broad beans are nitrogen fixers and will acidify over-fed soil. A base dressing of potassium and phosphorus (e.g. superphosphate) before sowing supports root and pod development. No nitrogen feed required. 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 aquadulce broad 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 aquadulce broad bean

Follow the crop-feed label rate for aquadulce broad 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 aquadulce broad bean first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the aquadulce broad bean watering schedule.

Signs you are over-feeding aquadulce broad bean

Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for aquadulce broad 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 aquadulce broad 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 aquadulce broad 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 aquadulce broad 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 aquadulce broad 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 aquadulce broad bean — frequently asked questions

What fertiliser does aquadulce broad 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. Aquadulce Broad 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 aquadulce broad bean?

Minimal fertiliser needed — broad beans are nitrogen fixers and will acidify over-fed soil. A base dressing of potassium and phosphorus (e.g. superphosphate) before sowing supports root and pod development. No nitrogen feed required. Minimal fertiliser needed — broad beans are nitrogen fixers and will acidify over-fed soil. A base dressing of potassium and phosphorus (e.g. superphosphate) before sowing supports root and pod development. No nitrogen feed required. 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 aquadulce broad bean?

What does over-feeding aquadulce broad 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 aquadulce broad 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 aquadulce broad bean?