Pea Shoots Nutrient, pH & EC Guide for Hydroponics

Pea shoots are one of the most nutrient-dense and commercially versatile microgreens, offering a sweet, fresh pea flavour and substantial texture. They are unique among microgreens in their ability to regenerate after the initial cut - embryonic stem tissue at the base of the shoot survives the harvest cut and produces harvestable side shoots for a second yield. This regrowth capacity makes pea shoots the highest effective yield-per-tray microgreen in most production setups.

pH and EC Targets

| Stage | pH | EC (mS/cm) | PPM (approx) | Notes | |-------|-----|------------|--------------|-------| | Germination (blackout) | 6.0–7.0 | 0.0–0.5 | 0–250 | Soak seeds 8–12 hours before sowing; pea seeds are large and benefit from pre-soaking | | Post-blackout growth | 6.0–7.0 | 0.8–1.2 | 400–600 | Seed stores supply primary nutrition; light solution supports shoot elongation | | Second-cut (side shoot) phase | 6.0–7.0 | 0.8–1.2 | 400–600 | Maintain dilute solution to support regrowth from cut stems |

Note on PPM: Values above use a 500 conversion factor (EC × 500 = PPM). Some meters use 700 - multiply by 1.4 to convert.

Key Nutrients

| Nutrient | Role in This Plant | Deficiency Sign | Correction | |----------|-------------------|-----------------|------------| | Folate | Among higher microgreen sources of dietary folate; concentrated from legume cotyledons | Not visibly detectable; seed-quality and harvest-timing dependent | Harvest at shoot tip stage (10–14 days) for peak folate content | | Vitamin C | Elevated in shoot tips vs mature pea tissue; present in expanding leaves at tips | Not visibly detectable | Harvest shoot tips before tendrils become the dominant feature of the stem | | Protein | Legume cotyledons retain significant seed protein during germination; pea shoots are notably high-protein for a microgreen | Not applicable at this stage | Pea shoot protein content is a variety and seed-quality variable |

Deficiency Identification

• Yellowing of shoot tips: Insufficient light after blackout removal. Move immediately to 150–200 µmol PPFD; yellowing resolves within 12–24 hours in adequate light.
• No regrowth after first cut: Cut was made too low (below the lowest viable node). Leave at least 2–3 cm of stem above the growing medium when harvesting. Side shoots emerge from the nodes above the cut point.
• Thin, leggy shoots: Insufficient light during the post-blackout growth phase. Increase light intensity or reduce distance from light source.
• Mould on growing medium: Overwatering or insufficient airflow. Bottom-water only; allow surface to show slight dryness between irrigations.

Feeding Schedule Notes

Pre-soak large pea seeds for 8–12 hours before sowing to speed germination - pea seeds are dense and benefit more from pre-soaking than smaller microgreen seeds. Sow in a single dense layer (30–40g per 10×20 cm tray). Apply a weighted cover during the 2–3 day blackout period and remove once shoots are 2–3 cm tall. Move immediately to 150–200 µmol PPFD and begin light bottom-watering with dilute solution at EC 0.8–1.2. Harvest the first cut at 10–14 days by cutting 2–3 cm above the medium surface - this height preserves the embryonic node tissue needed for regrowth. Maintain the same light and dilute solution for 7–10 more days and harvest side shoots for the second cut, typically 40–60% of first-cut volume.

Research note: Pea shoots can be harvested twice: first cut at 10–14 days, second harvest of side shoots 7–10 days later at 40–60% of first-cut volume. They are the only microgreen that reliably regrows.