- Home
- Vegetables
- Corn
How Often To Water Corn?
Water corn deeply about once a week, giving 1 to 2 inches, with the most care at tasseling and silking. Learn when to stop so the ears fill out well.
Water corn deeply about once a week, giving 1 to 2 inches of water, and twice a week in hot, dry spells. Corn needs the most water from tasseling through silking, when the kernels form. Ease off as the ears ripen, and stop a week or so before harvest.
A starting point, not a rule. Check the soil before each watering and stretch the gap in cool, cloudy weather.
On this page
Corn grows fast. On a warm July day, a single stalk can use close to a quart of water, and a patch of corn drinks more than almost anything else in the vegetable garden.
The good news is that corn grows deep roots, often 2 to 3 feet down, so it does best with deep soaks rather than frequent light watering. Your job is to deliver a deep drink each week, and make sure it never goes dry at the moment the ears are forming.
Corn watering schedule
| Growth stage | How often |
|---|---|
| Seeds until they sprout | Every 1 to 2 days, lightly |
| Seedlings, knee high | Once a week, about 1 inch |
| Rapid growth, summer | 1 to 2 times a week |
| Tasseling and silking | Twice a week, 1 to 2 inches total |
| Ears filling to harvest | Once a week, then stop a week before |
Count rain. An inch of rain replaces a watering.
How to tell when corn needs water
Push a trowel 4 to 6 inches into the soil beside a row. If it is dry at that depth, water. Corn roots go deep, so the top inch alone tells you little.
Corn leaves curl inward like a tube when thirsty. If they are curled in the morning, not just at midday, the plant needs water now.
How to water corn
- Water deeply. Soak the soil 8 to 12 inches down with a soaker hose or a slow sprinkler.
- Water in the morning. Leaves dry fast, and the plants are ready for the heat.
- Keep soil evenly moist during pollination. This is the critical window.
- Mulch between the rows. Straw cuts evaporation and keeps weeds down.
Signs of overwatering and underwatering
Too much water
- Yellowing, stunted plants
- Shallow roots and leaning stalks
- Fungal spots on leaves
- Soggy soil between rows
Too little water
- Leaves rolled in the morning
- Poor pollination and gaps in the ear
- Small, shriveled kernels
- Short, weak stalks
When to stop watering corn
Sweet corn is ready about 18 to 24 days after the first silks appear. Keep watering steadily until the silks turn brown and dry. Then cut back, and stop about a week before you plan to pick.
Corn grows best in blocks of short rows, not one long line, so the wind spreads pollen. Group it with other heavy feeders and drinkers. For the rest of your beds, see our guide to the vegetable garden, and for climbers that grow well alongside, see pumpkins.
Corn watering FAQ
How much water does corn need?
About 1 to 2 inches a week, including rain. Corn needs the most while tasseling and silking.
Can you overwater corn?
Yes. Soggy soil stunts growth and encourages disease. Water deeply but let the soil breathe between soaks.
When should I stop watering corn?
About a week before harvest, once the silks have turned brown and dry and the ears are nearly full.
We turn horticulture research and real growing experience into plain-English watering schedules you can actually follow.