Feeding and water Lifecycle Flowering Seedling Vegetative
How to water cannabis, and how to tell too much from too little
In soil, water thoroughly, then wait until the pot feels noticeably lighter before watering again. Coco gets watered more often. Drooping can mean too much water or too little, so lift the…
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Overwatering is a common problem: the root zone stays too wet for the roots to get enough oxygen. How often you water matters, but so do drainage, medium structure, pot size and root development.
Soil versus coco
| Soil | Coco and perlite | |
|---|---|---|
| When to water | When the top couple of inches are dry and the pot feels much lighter | Often, sometimes daily, once roots fill the pot |
| How much | Enough to wet the whole pot, slowly | Until some drains out the bottom |
| Plain water? | Sometimes, depending on your soil | Usually regular complete nutrient solution in unamended coco; follow the system program |
The lift test
- Lift the pot just after watering and remember how heavy it feels.
- Lift it again each day. Water when it has lost a good portion of that weight.
Don’t water on a fixed calendar. A bigger plant drinks much faster than a small one.
Too much or too little?
| Sign | Overwatered | Underwatered |
|---|---|---|
| Pot weight | Heavy | Very light |
| Leaves | Thick, curled down, stems still firm | Limp and thin, stems droop too |
| Recovery | Slow, days | May recover quickly after watering if roots are healthy |
Plants also droop a bit shortly before the lights go off. That’s normal, so judge them mid-day.
Drainage matters
If pots stay soggy, check drainage and see the container guide.
Leaf posture is only a clue. Heat, root disease, salts and other problems can also cause drooping. The pot-weight routine mainly fits top-watered potting mix. Don’t force a soil-style dryback on water culture, and don’t let coco dry out completely.
Sources (3)
- University of Maryland Extension. Growing vegetables in containers and salad tables. https://extension.umd.edu/resource/growing-vegetables-containers-and-salad-tables [Evidence access: EXTENSION TEXT VERIFIED.]
- University of Minnesota Extension. Small-scale hydroponics. https://extension.umn.edu/how/small-scale-hydroponics [Evidence access: EXTENSION TEXT VERIFIED.]
- Punja, Z. K., Collyer, D., Scott, C., Lung, S., Holmes, J., & Sutton, D. (2019). Pathogens and molds affecting production and quality of Cannabis sativa L. Frontiers in Plant Science, 10, 1120. https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2019.01120/full [Evidence access: FULL TEXT VERIFIED.]