What the colours mean
Every reading on every soil probe gets a dot for how it compares with what vegetables in a raised bed like.
| Reading | Good | Fair | Poor |
|---|---|---|---|
| Soil temperature | 55–85°F | 40–55 or 85–95°F | below 40 or above 95°F |
| Moisture | 20–35% | 12–20 or 35–45% | below 12 or above 45% |
| Conductivity (EC) | 100–1,000 µS/cm | 50–100 or 1,000–2,000 µS/cm | below 50 or above 2,000 µS/cm |
| Nitrogen (N) | 20–60 mg/kg | 10–20 or 60–100 mg/kg | below 10 or above 100 mg/kg |
| Phosphorus (P) | 15–50 mg/kg | 8–15 or 50–100 mg/kg | below 8 or above 100 mg/kg |
| Potassium (K) | 120–250 mg/kg | 80–120 or 250–400 mg/kg | below 80 or above 400 mg/kg |
| pH | 6.0–7.0 | 5.5–6.0 or 7.0–7.5 | below 5.5 or above 7.5 |
Temperature: roots and soil life are most active at 55–85°F, slow below 40°F and are stressed above 95°F.
Moisture: loam is fully watered at about 30–35% and plants start to wilt around 10–12%; above 45% it is waterlogged.
EC: low means few dissolved nutrients, very high means salt stress; it reads lower when the soil is dry.
N, P, K: standard soil-test targets. These probes estimate N/P/K from conductivity and read far below lab values, so they usually show red; watch their trend instead.
pH: 6.0–7.0 suits most vegetables.
Change in the last hour
Above each reading: +0.6°F ↑ red when it went up, −0.4% ↓ blue when it went down, 0.0 → grey when it held steady. It shows once a probe has an hour of readings. These are just the direction of change, not good or bad.