Tips for watering cucumbers
Growing cucumbers in a greenhouse during the warm season requires maintaining the right level of soil moisture. Before the plant begins to flower, water in the morning; once flowering starts, the best time is in the evening, after sunset. The optimal water temperature is +21–25 °C and should never drop below +12 °C.
How much water do greenhouse cucumbers need?
Cucumbers need roughly 4–13 liters of water per square meter, depending on growth stage — about 1.5–4.5 liters per plant every 2–3 days if you grow 3 plants per m². Typical amounts:
| Growth stage | Water per m² | Per plant (3/m²) | Frequency |
|---|---|---|---|
| Young plants (before flowering) | 4–5 L | ~1.5 L | Every 2–3 days, morning |
| Flowering | 10–12 L | 3–4 L | Every 3 days, evening |
| Fruiting | 12–13 L | ~4–4.5 L | Every 3 days, evening |
Water temperature matters more for cucumbers than for most crops: aim for +21–25 °C and never water with anything colder than +12 °C.
How can you tell if cucumbers are overwatered?
Yellowing leaves, slow growth, mold, fungus, or rotting roots indicate overwatering. If you notice these problems, immediately reduce the amount of water and allow the soil to dry more thoroughly before watering again.
Cucumber leaves starting to yellow.
How can you tell if cucumbers are underwatered?
If cucumbers receive too little water and soil moisture is low, growth will slow, the soil will appear overly dry, and plants may wilt or curl their leaves. Regularly inspect and assess the plant's condition — the best time is during the hottest part of the day, when wilting is most visible.
Frequently Asked Questions
Should cucumbers be watered in the morning or evening?
Before flowering — in the morning. After flowering starts — in the evening, after sunset.
What water temperature do cucumbers need?
+21–25 °C is optimal; never below +12 °C — cold water shocks the roots and slows growth.
Can watering be automated?
Yes — a soil-moisture-driven system like the GRAAS iRigator keeps cucumber soil in the right range automatically and can water each zone on its own schedule.