Garden Update — Thursday, 19 March 2026
Daily insights generated from live sensor and weather data, compared across 3 AI models. Sensor data from Ecowitt GW1200 · Weather from Open-Meteo · Dunedin, NZ
7-Day Weather Forecast
🌅 Sunrise: 7:35 AM · Sunset: 7:56 PM · Day length: 12.4 hrs
| Date | Max | Min | Rain | Rain% | Wind | UV | ET₀ | Radiation |
|---|---|---|---|---|---|---|---|---|
| 19/03 | 16.2°C | 11.2°C | 0.0mm | 0% | 17kph | 5.5 | 2.2mm | 15.5MJ/m² |
| 20/03 | 15.7°C | 12.0°C | 0.0mm | 0% | 11kph | 5.3 | 1.8mm | 12.1MJ/m² |
| 21/03 | 17.5°C | 10.6°C | 0.0mm | 0% | 11kph | 5.4 | 2.6mm | 17.9MJ/m² |
| 22/03 | 18.0°C | 11.9°C | 0.0mm | 35% | 6kph | 4.0 | 2.4mm | 16.3MJ/m² |
| 23/03 | 17.1°C | 11.1°C | 0.0mm | 14% | 9kph | 5.3 | 2.1mm | 14.5MJ/m² |
| 24/03 | 18.9°C | 10.3°C | 0.0mm | 5% | 6kph | 5.0 | 2.5mm | 17.5MJ/m² |
| 25/03 | 16.0°C | 10.6°C | 0.0mm | 5% | 15kph | 0.9 | 2.1mm | 16.6MJ/m² |
Generated at 7:45 AM NZDT
AI Model Comparison
⚠️ 2 model(s) did not respond:
claude-opus-4-6,claude-sonnet-4-6
🟢 OpenAI — gpt-5.4
The brassica bed has slipped into a clear moisture deficit and now needs watering despite the soil sensor still sitting within the nominal brassica range. No live sensor reading is available today, which lowers confidence, but the 7-day soil-moisture trend has fallen from 48–52% on 13/03 to 45–46% on 17–18/03 while the past week ran about 4.7 mm drier than rain supplied. At 20 days from planting, the broccoli, cauliflower, and cabbage are still establishing, so steady moisture is more important than any crop-specific intervention.
Observations
- No live sensor data available → today’s decisions must rely on the 7-day trend and weather balance, so confidence is lower than if a current reading were present.
- Soil moisture drifted down from 47.0–52.0% on 13/03 to 45.0–46.0% on 17–18/03 → the whole brassica bed is drying toward the lower half of the ideal 40–60% band, especially relevant for recently transplanted broccoli, cauliflower, and cabbage.
- Past 7 days rain total 19.8 mm versus ET₀ total 24.5 mm → the bed is carrying an accumulated moisture deficit of about 4.7 mm despite acceptable recent sensor values.
- Forecast rain for 19–21/03 is 0.0 mm while ET₀ totals 6.6 mm over the same three days → the current drying trend is likely to continue unless water is added.
- Recent minima stayed mild at 8.6–14.5°C in the sensor trend and 9.2–12.6°C in the past-week actuals → there is no frost-driven slowdown or protection trigger for these young brassicas today.
Actions for Today
-
Brassica bed — establishment phase (20 days from planting)
7-day soil moisture has fallen to 45–46%, past-week rain minus ET₀ is about -4.7 mm, and the next 3 days forecast 0.0 mm rain with 6.6 mm ET₀ → the bed is drying while transplants are still establishing roots → water the whole bed today, preferably in the morning, with about 8–10 L total across the 3.74 m² bed, applied slowly under the mulch so it soaks in rather than runs off. -
Brassica bed — early vegetative establishment
Compost was incorporated before planting, seaweed tonic was applied at planting on 28/02, and the plants are only 20 days in → root establishment is still the priority and there is no data signal here for nutrient shortage → after watering, check that the comfrey mulch laid on 12/03 still leaves a small clear collar around each stem; pull mulch back a few centimetres from stems if it is touching them.
Skip today
- Blanching cauliflower heads — plants are only 20 days from planting and there is no evidence of curd formation yet.
- Harvesting any broccoli, cauliflower, or cabbage — all crops are still in establishment, well before the expected May–July harvest window.
- Re-feeding with tonic or fertiliser — recent drying, not nutrition, is the data-supported issue today.
Variety Watch
Broccoli (Green Dragon, Purple, Side Sprouter) — establishment — keep soil moisture from sliding below the mid-40% range
Cauliflower (White, Cheddar, Violet) — establishment — even moisture matters most while roots settle in
Cabbage (Lion Heart, Dutch Red, Cannonball) — establishment — drying trend is the main pressure, not cold
Looking Ahead
The key change is not weather shock but continued drying: 19–25/03 shows essentially no meaningful rain and daily ET₀ of 1.8–2.6 mm. If the bed is watered today, be ready to reassess by 22–24/03 because another 6–7 mm of atmospheric demand is forecast by then.
Horticulture
Young brassicas are unusually sensitive to irregular soil moisture because most of their effective root mass is still concentrated in the upper soil layers. When that zone dries, stomata begin to close to limit water loss, and growth slows before leaves visibly wilt. In brassicas, this early check to growth reduces leaf area expansion, which matters because head and curd size later depend on how much photosynthetic canopy the plant builds first. Mulch helps by reducing evaporation from the soil surface, but it cannot replace water that the atmosphere is steadily pulling out when ET₀ stays elevated for several days.
The bed has held its green through a run of bright, dry afternoons while the moisture numbers have edged down day by day.
This post was auto-generated by the Garden AI pipeline. Weather data from Open-Meteo · Claude & GPT insights · Built with Astro