Cannabis Watering Schedule: How Often to Water Weed

How often should you water cannabis?

Short answer: water when the top inch or two of your medium is dry, not on a fixed calendar. In soil that usually works out to every 2 to 3 days in veg, and closer to every 1 to 2 days in late flower. In coco coir or a hydro setup, expect to water daily, sometimes twice a day once plants get big.

best watering schedule for autoflowering weed

I've seen more grows wrecked by a rigid watering schedule than by almost any nutrient mistake. Roots need oxygen between drinks. Water too often and you drown them.

best watering schedule for autoflowering weed

Watering by stage

Seedlings and clones

• Small root zone, tiny drinks. An ounce or two of water around the stem, not the whole pot.
• Every 2 to 3 days in soil, closer to daily in coco.
• A humidity dome helps the first week, but lift it once a day for air.

Vegetative stage

• Roots fill the pot, so drinks get bigger, then more frequent as the plant grows into the container.
• Soil: every 2 to 3 days. Coco: daily.
• Water until you see a little runoff, then stop.

Flowering

• Demand peaks around weeks 4 to 7. Every 1 to 2 days in soil is normal.
• Late flower, plants drink less as they ripen. Back off and let the medium dry a bit more.
• Keep things evenly moist but never soggy, since standing water invites bud rot and mold.

How to tell it's time to water

Lift the pot. A dry pot weighs almost nothing; a freshly watered one feels like a bag of sand. After a few weeks you'll trust your hand more than any meter. Stick a finger in an inch deep. Dry at the tip, water. Damp, wait.

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Signs you're overwatering: droopy leaves that stay droopy after watering, yellowing that starts low on the plant, fungus gnats, stalled growth. Signs of underwatering: leaves that perk up within an hour of watering, crispy edges, pots that feel weightless.

how often to water cannabis plants

Water quality and pH

pH matters more than most people think. Soil: 6.0 to 7.0. Coco and hydro: 5.5 to 6.5. Tap water left out overnight lets chlorine off-gas. Cold water shocks roots, so let it sit at room temperature first.

In coco, aim for 10 to 20 percent runoff each watering to flush salt buildup. In living soil, runoff isn't needed unless you're correcting a problem.

Environment changes everything

Heat, airflow, pot size, and light intensity all move the needle. A 5-gallon pot in a cool room can go 3 days. The same plant under a hot LED in a tent might need water daily. Watch the plant, not the clock. That's the whole schedule.