Fertilising guide

How to fertilise Britton Perilla (Perilla frutescens 'Britton')— schedule & NPK

Also called Britton Perilla, Shiso, Beefsteak Plant.

More about britton perilla

About Britton Perilla

Perilla frutescens 'Britton' · also called Britton Perilla, Shiso · edible

Britton Perilla is a compact, upright cultivar of shiso with deeply ruffled, dark-green to bronze-tinged leaves and a spicy, anise-mint flavor. Ideal for edible gardens and containers, it thrives in full sun to part shade with regular moisture. A fast-growing annual herb used widely in Asian cuisine, it self-seeds readily in warm climates.

Growth habit: Upright, bushy annual

What fertiliser britton perilla actually wants — and why

Britton Perilla 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 britton perilla: 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 britton perilla, 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 britton perilla:

Apply a balanced, general-purpose fertiliser (10-10-10) every 4–6 weeks during active growth, or top-dress with compost monthly. Avoid excessive nitrogen, which promotes overly soft growth at the expense of flavor. 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 britton perilla 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 britton perilla

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

Signs you are over-feeding britton perilla

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

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 britton perilla

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 britton perilla 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 britton perilla 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 britton perilla

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 britton perilla — frequently asked questions

What fertiliser does britton perilla 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. Britton Perilla 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 britton perilla?

Apply a balanced, general-purpose fertiliser (10-10-10) every 4–6 weeks during active growth, or top-dress with compost monthly. Avoid excessive nitrogen, which promotes overly soft growth at the expense of flavor. Apply a balanced, general-purpose fertiliser (10-10-10) every 4–6 weeks during active growth, or top-dress with compost monthly. Avoid excessive nitrogen, which promotes overly soft growth at the expense of flavor. 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 britton perilla?

What does over-feeding britton perilla 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 britton perilla 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 britton perilla?