If you run a vineyard, it pays to learn the BBCH scale. It is an international system describing plant growth stages, from winter dormancy to leaf fall. Most decisions in the vineyard depend on which stage your plants are in.
Why know the BBCH stages?
Crop protection. Product labels say „apply at BBCH stage 12-15". If you do not know the stage, you do not know when to spray.
Frost. Cold tolerance changes dramatically with the stage. Dormant buds survive down to -15°C, but a flowering vine dies already at -0.5°C.
Diseases. Powdery mildew mainly attacks in stages 15-85, and grey rot during ripening (79-89). We measure the microclimate that favours these diseases right at the leaf, which we wrote about in the leaf sensor post.
The key stages of the season
Early spring
The season starts with bud swell (BBCH 05) in March. In April the buds break and the characteristic „wool stage" appears (BBCH 09). The first leaves come out at the turn of April and May.
Flowering, the most critical moment
June is flowering time (BBCH 61-69). It is the most sensitive phase, when any frost, heavy rain or hail can significantly reduce yields. The vine flowers briefly, so it is worth watching it daily.
Fruit set and ripening
After flowering the berries grow from pinhead size to ripe clusters. The key moment is veraison (BBCH 81), the onset of ripening, when berries change colour and start accumulating sugar. From then on you measure Brix every week.
Frost tolerance by stage
This is the most underrated aspect. The rough values look like this.
- Dormancy (BBCH 00-05): down to -15°C
- Bud break (BBCH 09-11): down to -3°C
- Inflorescences and flowering (BBCH 53-71): down to -0.5°C, the moment of greatest exposure
- Ripe berries (BBCH 85+): down to -2°C
VineyardElf automatically accounts for the growth stage when calculating frost alert thresholds. If you have the phenology module enabled, the alerts adapt to the current stage.
How to record the stages?
Manual observation. Once a week walk the vineyard and note the stage. Five minutes, and the data is priceless in the years to come.
Automatic estimation. The system estimates the stage from accumulated temperature (GDD, that is Growing Degree Days). Rough, but useful as a starting point.
After a few seasons you will have a comparison of when each variety reached the key stages and how the weather affected the pace of development.
Summary
Knowing the BBCH stages is the foundation of running a vineyard consciously. It lets you make decisions based on data, not intuition. And VineyardElf helps you collect and use that data, from frost alerts to a spraying schedule. In fact, exactly these problems from our own vineyard became the root of VineyardElf.