"Plant strawberries in coco, add nutrients — three months later, berries." Three months pass: lush green foliage, runners everywhere, and not a single berry.
In a controlled environment, strawberries require specific conditions to fruit — unlike their natural seasonal cycle outdoors.
Variety Is Everything: Short-Day vs Day-Neutral
Short-day varieties (traditional, June-bearing): initiate generative buds when nights exceed 12–14 hours and require artificially shortened days (8–10 hours) to fruit in a controlled environment.
Day-neutral varieties: fruit regardless of day length at temperatures of 15–28°C — the recommended choice for indoor production. Recommended varieties: Albion, Seascape, Monterey, Portola. Berries are somewhat smaller than short-day types, but fruiting is continuous over 9–12 months.
Everbearing varieties: fruit twice per season — less predictable for year-round indoor production.
Planting Material: Frigo vs Pot Plants
Frigo transplants — field-dug plants stored frozen at −2°C with formed generative buds. Class A+ or A guarantees a predictable time to first harvest.
Pot plants — less expensive, but fruiting timelines are less predictable and quality depends on the mother plant.
EC and Nutrition by Growth Phase
- Establishment (weeks 1–3): EC 0.8–1.2 mS/cm
- Vegetative phase: EC 1.2–1.8 mS/cm; calcium and potassium play a critical role
- Fruiting: EC 1.8–2.5 mS/cm with elevated potassium and reduced nitrogen
Excess nitrogen during fruiting produces large vegetative mass and small, acidic berries. pH: 5.8–6.2 at all phases.
Lighting and Photoperiod for Day-Neutral Varieties
- DLI 17–25 mol/m²/day for active fruiting
- Below DLI 15 — slow flowering, small berries, extended cycle
- Photoperiod: 12–16 hours
- Optimal temperature: 18–22°C during vegetative growth, 20–24°C during fruiting
Pollination in a Controlled Environment
Strawberries require pollination. Signs of poor pollination: deformed, "button" berries. For commercial production — a bumblebee hive (Bombus terrestris) or manual pollination with a soft brush at each flower opening.
Three Mistakes That Cost the Most
- Choosing a short-day variety for year-round production — without photoperiod control, fruiting will not occur
- Not reducing nitrogen at the transition to fruiting — excessive vegetative growth, poor berry development
- Ignoring pollination indoors — deformed berries despite normal flowering
Signs That Strawberries Are in Optimal Conditions
- Continuous, even flowering over 8–10 months in day-neutral varieties
- Berries with correct shape and uniform colour
- Sweet flavour with pleasant acidity and no wateriness