Step 1
Water the soil, not the leaves. Water that collects on a plant’s leaves can promote disease, especially on leaves of nightshades (such as potatoes and tomatoes) and cucurbits (such as zucchini).
Step 2
Water in the morning. Watering early in the morning allows plants to absorb water before the sun gets high and the air heats up, providing your plants with fuel to withstand the heat of the day. Watering in the morning also allows plenty of time for any water to evaporate from leaves, which reduces the possibility of fungal diseases encouraged by cooler nighttime temperatures. Second best is watering in the evening; least desirable is at midday.
Step 3
Water deeply, not more frequently. Better to water infrequently for longer periods of time, allowing water to soak in thoroughly, than to lightly sprinkle the surface of the soil every day. Plants’ roots go where the water is. If you water deeply, roots will grow deep into the soil, and the plants will be better able to withstand drought and winds. Shallow watering encourages root growth at the soil surface, leaving the plant without a strong anchor and with no defense against wind and drought.
Step 4
How often you should water depends on a number of factors. Young seedlings and transplants require more frequent watering than do established plants and trees. All plants require more frequent watering in hot weather. Sandy soils do not hold water as well as clay soils that require less frequent watering. And, finally, container gardens need watering more often than in-ground gardens.
Step 5
Several signs can indicate that a plant needs water, such as soil that is pulled away from the sides of a container, and plants with limp, floppy leaves. Before you let them get that far, try a variation on the cake-readiness test. Stick your finger into the soil past the first knuckle. If the soil feels dry and doesn’t stick to your finger when you pull it out, add water. Small containers can be checked by lifting them up; you’ll soon get a feel for how heavy they should be when well-watered.