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BBCH Phenological Scale (Reference)

The BBCH scale is a standardised numeric system used to describe plant growth stages across many crops.

It provides a common language for: - Crop development - Research and regulation - Comparing growth stages across sites and seasons

Agrinomy uses BBCH as a reference framework, alongside practical stage descriptions.

What BBCH means

BBCH is named after: - Biologische - Bundesanstalt - Chemische - Hindustrie

The system assigns a two-digit code to plant development stages.

BBCH structure

  • First digit (0–9) → principal growth stage
  • Second digit (0–9) → secondary stage within that phase

Example: - BBCH 65 = full flowering
- BBCH 71 = fruit set / early fruit development

Principal BBCH stages (generalised)

Code Stage Description
0 Germination / sprouting Seedling emergence
1 Leaf development True leaves forming
2 Side shoot development Branching
3 Stem elongation Internode growth
4 Vegetative structures Rosette / canopy
5 Inflorescence emergence Flower structures visible
6 Flowering Bloom, pollination
7 Fruit development Fruit set and growth
8 Ripening Maturity
9 Senescence Ageing / dormancy

Not all crops use all stages.

BBCH in horticultural crops

Tomato (example mapping)

Practical stage Approx. BBCH
Establishment 10–15
Vegetative build 15–39
First flowering 51–59
Full flowering 60–69
Fruit set 71–79
Fruit fill 79–85
Ripening 85–89
Late season 89–99

Strawberry (example mapping)

Practical stage Approx. BBCH
Leaf development 11–19
Flower initiation 51–55
Flowering 60–69
Fruit set 71–75
Fruit development 75–85
Harvest 85–89

Lettuce (example mapping)

Practical stage Approx. BBCH
Leaf development 11–19
Head formation 41–49
Harvest window 49–51

Why BBCH is useful (and where it isn’t)

Useful for:

  • Comparing seasons and sites
  • Linking crop stage to thermal time
  • Research, trials, and advisory benchmarks
  • Regulatory and label references

Less useful for:

  • Day-to-day management decisions
  • Climate control timing
  • Irrigation response

For practical growing, stage awareness matters more than exact codes.

How Agrinomy uses BBCH

Agrinomy treats BBCH as: - A reference index, not a rigid control system - A bridge between research, trials, and real-world growing - A way to anchor phenology to GDH/GDD and climate strategy

Users do not need to log BBCH codes to benefit from phenological tracking.

Key principle

BBCH describes where the crop is — it does not tell you what to do.

Management decisions still depend on: - Climate - Root-zone conditions - Crop load - Stress history