Fertilising guide

How to fertilise Telephone Pea (Pisum sativum 'Alderman')— schedule & NPK

Also called Alderman pea, Telephone pea, tall telephone.

More about telephone pea

About Telephone Pea

Pisum sativum 'Alderman' · also called Alderman pea, Telephone pea · edible

'Alderman', also sold as Telephone, is a tall heirloom shelling pea reaching 1.8-2.4 m and needing sturdy support. It yields long pods of large, sweet wrinkle-seeded peas over a long picking window. A cool-season legume, it fixes nitrogen, crops best in spring and autumn, and sulks in summer heat above 24°C.

Growth habit: Tall, vigorous climbing/vining annual that clings by tendrils. Indeterminate-style growth keeps flowering and podding up the stem over weeks, demanding tall netting, canes or trellis.

What fertiliser telephone pea actually wants — and why

Telephone Pea 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 telephone pea: 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 telephone pea, 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 telephone pea:

Low feeder thanks to nitrogen fixation. Work compost into the bed before sowing; if growth is weak, apply a balanced, low-nitrogen feed once at flowering. Skip high-nitrogen fertiliser, which delays podding. 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 telephone pea 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 telephone pea

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

Signs you are over-feeding telephone pea

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

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 telephone pea

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 telephone pea 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 telephone pea 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 telephone pea

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 telephone pea — frequently asked questions

What fertiliser does telephone pea 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. Telephone Pea 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 telephone pea?

Low feeder thanks to nitrogen fixation. Work compost into the bed before sowing; if growth is weak, apply a balanced, low-nitrogen feed once at flowering. Skip high-nitrogen fertiliser, which delays podding. Low feeder thanks to nitrogen fixation. Work compost into the bed before sowing; if growth is weak, apply a balanced, low-nitrogen feed once at flowering. Skip high-nitrogen fertiliser, which delays podding. 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 telephone pea?

What does over-feeding telephone pea 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 telephone pea 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 telephone pea?