Question 1

What are Growing Degree Days (GDD) in viticulture?

Accepted Answer

Growing Degree Days measure accumulated heat above a base temperature (10°C/50°F) during the growing season. In viticulture, GDD determines grape ripeness potential, predicts phenological stages like budburst and veraison, and classifies vineyard climates into Winkler Regions I-V. VineyardVitals automatically calculates GDD from your weather station data in both Fahrenheit and Celsius.

Question 2

What is the Huglin Index and why does it matter for wine?

Accepted Answer

The Huglin Index (or Heliothermal Index) is a viticultural heat summation that emphasizes maximum daytime temperatures and includes a day-length correction factor based on latitude. It better predicts grape sugar accumulation than simple GDD. VineyardVitals computes the Huglin Index daily with automatic latitude-based corrections.

Question 3

How do I track disease risk in my vineyard?

Accepted Answer

VineyardVitals includes 6 disease forecasting models calculated daily from your weather station data: Gubler-Thomas Powdery Mildew Risk Index, Downy Mildew (Baldacci 3-10 Rule), Botrytis Bunch Rot (Broome model), Black Rot (Spotts wetness-duration model), Phomopsis Cane & Leaf Spot, and Anthracnose. The dashboard shows disease pressure alerts at moderate (≥30) and high (≥60) risk thresholds with actionable spray timing recommendations. Models use temperature, precipitation, humidity, and wet leaf hours to estimate infection risk.

Question 4

What disease models does VineyardVitals use for spray timing?

Accepted Answer

VineyardVitals uses peer-reviewed disease models adapted from published viticulture research. Powdery mildew uses the UC Davis Gubler-Thomas Risk Index. Downy mildew uses the Baldacci 3-10 Rule for primary infection and an hour-degree model for secondary infection. Botrytis follows the Broome (1995) model and the two-fifteens rule. Black rot uses the Spotts (1977) temperature-wetness duration table. All models run as daily proxies from weather summary data and should supplement — not replace — in-vineyard scouting and professional pest management advice.

Question 5

What weather stations work with VineyardVitals?

Accepted Answer

VineyardVitals integrates with WeatherFlow Tempest, Ambient Weather (WS-2902, WS-5000), Davis Instruments via WeatherLink, Weather Underground personal weather stations, Visual Crossing (blended station + model data), Open-Meteo (free satellite reanalysis), and Meteomatics gridded data. You can also import historical data from any source using CSV or Excel files with our auto-mapping import tool.

Question 6

What is BEDD and how does it differ from GDD?

Accepted Answer

Biologically Effective Degree Days (BEDD) adjusts standard GDD calculations to account for the fact that vine growth slows at extreme temperatures. It applies an upper temperature cap and adjusts for diurnal temperature range. VineyardVitals computes both Gladstones BEDD and Hall & Jones BEDD variants automatically from your daily weather data.

Question 7

How much does VineyardVitals cost compared to other vineyard software?

Accepted Answer

VineyardVitals offers a free tier with 1 station and season overview. The Pro plan is $20/month with up to 3 stations and full analytics. The Pro+ plan is $50/month with unlimited stations. All plans are month-to-month with no annual commitment. This is significantly more affordable than alternatives like 360viti which starts at $75/month with an annual commitment.