At what times is it most beneficial to irrigate plants?

Irrigating plants during late night or early morning is the most beneficial time primarily due to lower temperatures and reduced evaporation rates. Early morning irrigation allows plants to absorb water before the heat of the day increases, ensuring they have adequate moisture during hotter conditions. This timing also allows the water to soak into the root zone efficiently, as the soil is cooler and less likely to lose moisture to the atmosphere.

Irrigating during late evening can also ensure that the plants have sufficient moisture overnight, but it may risk fungal diseases due to prolonged leaf wetness. However, morning watering is preferred as it provides plants with the moisture they need during the hottest part of the day, improving overall plant health and resilience.

In contrast, watering during the hottest part of the day can lead to significant evaporation, wasting water and potentially causing water to evaporate before it properly reaches the roots. Similarly, watering at noon, even when temperatures are moderate, may still not be optimal because the heat can still cause rapid evaporation. Lastly, simply watering whenever the soil looks dry does not account for the specific needs of plants or the timing; it may lead to over or under-watering depending on varying environmental conditions throughout the day.