Short version: Don't water on a schedule — water on a cycle. Soak the pot until you get a little runoff, then wait until the top inch is dry and the pot feels light before watering again. Overwatering is the single most common way new growers stall (or kill) a plant, and it looks almost exactly like underwatering.
"How much should I water, and how often?" is one of the most common questions new growers ask us — and it's the one where generic advice does the most damage. There is no universal schedule, because how fast a pot dries depends on plant size, pot size, your medium, and your room's temperature and humidity. What you actually need is a simple method you can repeat, and the confidence to read the plant instead of the calendar.
Water on a wet/dry cycle, not a timer
Cannabis roots need oxygen as much as they need water. When a pot stays soggy, the air pockets in the medium fill with water and the roots effectively suffocate — growth slows, and you get the classic droop. The fix is the wet/dry cycle: fully saturate the root zone, then let it dry down before the next watering. That swing pulls fresh air into the medium as it dries and encourages roots to spread in search of moisture.
- Water thoroughly. In soil or coco, water until roughly 10–20% runoff drains from the bottom. This wets the whole root zone and rinses out excess salts.
- Then wait. Don't touch it again until the top 1–2 inches (2–5 cm) of medium are dry and the pot is noticeably lighter.
- Repeat. As the plant grows, the cycle gets shorter — a seedling might go 3–5 days between waterings; a big plant in a fabric pot during flower might need water daily.
The pot-lift test beats any schedule
The most reliable moisture gauge you own is your own hand. Water a pot fully, then lift it — memorize that "heavy" feeling. Lift it again when it's bone dry and memorize "light." From then on, a quick lift tells you exactly where you are in the cycle. Fabric pots dry faster than plastic (they breathe from the sides), so factor that in. A cheap moisture meter or simply pushing a finger two knuckles deep both work too.
Overwatering vs. underwatering: they look the same
This trips up almost everyone. Both overwatered and underwatered plants droop — so the leaves alone won't tell you which mistake you're making. Check the medium:
- Overwatered: drooping leaves that feel firm and curled, medium still wet days after watering, slow growth, sometimes yellowing. The pot feels heavy.
- Underwatered: drooping leaves that feel thin, papery, and limp, medium bone dry, pot very light. Plants usually perk up within an hour or two of a good drink.
When in doubt, wait. It's far easier to rescue a thirsty plant than a drowned one. If you suspect the leaf symptoms are actually a feeding problem rather than water, our nutrient deficiency guide walks through what each color and pattern means.
Get the water itself right
What's in the water matters as much as the amount:
- pH it. Aim for 6.0–6.5 in soil and 5.5–6.5 in coco or hydro. Off-range water locks out nutrients even when they're present — a common hidden cause of "deficiencies."
- Temperature: use room-temp water (around 18–22°C / 65–72°F). Cold water shocks roots.
- Chlorine: if you're on chlorinated tap, let it sit out a few hours or use a dechlorinator so you're not nuking the living soil.
- Feeding: if you're watering with nutrients, follow a stage-based plan rather than guessing — see our complete feeding schedule.
Watering seedlings and young plants
Seedlings have tiny root systems and drink very little. Flooding a big pot around a small seedling keeps the root zone swampy and invites damping off. Instead, water a small amount in a ring a few inches out from the stem — this stays moist enough for the seedling while encouraging the roots to stretch toward it. Keep the medium damp like a wrung-out sponge, never soaking. For everything else about the fragile early days, see our weeks 3–5 survival guide.
Frequently asked questions
How often should I water cannabis in soil?
There's no fixed number — water when the top 1–2 inches are dry and the pot feels light, which is roughly every 2–4 days for a young plant and as often as daily for a large plant in a fabric pot during flowering. The wet/dry cycle and the pot-lift test tell you far more than any schedule.
What are the signs of overwatering?
Firm, curled-down drooping leaves, a medium that stays wet for days, slow growth, and a heavy pot. Because underwatering also causes drooping, always check whether the medium is wet or dry before deciding — if it's still wet and drooping, you're overwatering.
Should I water every day?
Only if the pot actually dries out that fast, which usually happens only with large plants in small or fabric pots late in flower. Watering a pot that's still wet is how most beginners drown their plants. Let the medium dry back before each watering.
