Overwatering kills more vegetable plants than drought. The goal is consistent moisture at the root zone, not wet leaves or soggy soil.
The basic rule: Most vegetables need 1 inch of water per week, either from rain or irrigation. In hot, dry climates or during heat waves, increase to 1.5–2 inches.
How to measure 1 inch: Set a tuna can (2.5 inches deep) in your garden. Run your sprinkler until there's 1 inch in the can. That's your reference point.
When to water: Morning is best — leaves dry out during the day, reducing fungal disease. Evening watering leaves foliage wet overnight, inviting mildew and blight. Never water in the heat of midday (most evaporates before reaching roots).
Deep, infrequent beats shallow, frequent: Watering deeply (30–45 minutes) every 2–3 days grows deeper roots than light daily watering. Deep roots reach moisture that shallow roots can't, making plants more drought-tolerant.
The finger test: Stick your finger 2 inches into soil near plant roots. If it's dry, water now. If it's moist, wait. This beats any schedule — different weather, soil types, and plant stages all change water needs.
Drip irrigation: If you can invest in one thing, it's drip irrigation. It delivers water directly to roots, uses 30–50% less water than overhead sprinklers, and keeps foliage dry. Basic drip kits for raised beds run $30–60.
Critical periods: Some plants need consistent moisture during specific growth stages. Tomatoes need even moisture when fruit forms (irregular watering causes blossom end rot and cracking). Corn needs water during tasseling. Squash needs water during fruit set. Missing water at these moments costs yield.