How often to Water Cannabis?


Overwatering is the most common mistake that growers will make, especially new growers. Of course, water is key for cannabis since cannabis consists of 80% water (just like you!). In this article, we’re going to break down the frequency and volume of watering for an average cannabis plant. Of course, how often and how much water cannabis depends on the strain, whether it is auto-flowering, and what stage of growth it is in, so we will focus on generalities here.

When you start growing, be sure to research your specific strain, contact your seed seller, or get in touch with a grower community or a forum for more information. There are ways to tell whether you’re overwatering or underwatering, so be sure to keep an eye on that, too. Finally, the last factor is the medium you’re growing in—we’ll focus on soil since that is the most common medium our growers use. How often do water cannabis?

So to summarize, here are the factors that contribute to watering:

  1. Pot size
  2. Medium
  3. Health of plant
  4. Temperature and humidity
  5. Growth stage

We’ll break these down at the end of the article.

How often should you water cannabis?

Cannabis has different requirements for watering during different stages. The following recommended frequency of watering is concluded based on our experience. You can make some changes according to your situation. As a rule of thumb, if you press your finger into the soil and it feels dry up to your first knuckle (about 1 inch deep), or the pot is light, you can water.

Germination stage-How often to Water Cannabis

During this stage, the goal isn’t “watering” as much as it is ensuring that the environment is moist enough to support germination. If you plan to germinate seeds directly in the soil, you’ll need to ensure the soil is moist and you may need to actually “add” water every 4-7 days.

Seedling stage-How often to Water Cannabis

Cannabis doesn’t need much water during this stage.  It might be tempting to overwater your seedling because they are delicate, but please restrain yourself. Simply test whether the soil is damp by putting your finger into the soil to see if has dried out. If you are growing in a pot, you’ll likely find that you need to water every 3-7 days. This also depends on the size of the container.

Vegetative Stage-How often to Water Cannabis

Cannabis needs more water in this stage than in the seedling stage since they begin to grow leaves and branches. As usual, stick your finger into the soil about 1 inch and see if it is damp. If it is, don’t water. If it is dry, add water. If your plant is in its forever home (a large pot), you’ll likely be watering every 2-4 days.

Flowering Stage-How often to Water Cannabis

Watering in the flowering stage is a little challenging for growers since cannabis is mature and has different requirements for nutrients and usually soaks up water faster because it has flowers to produce. We recommend watering every 2-3 days but test your soil, as usual, to see if your plant even needs water.

There is a simple way to remember when to water cannabis:

When—If the soil is dry an inch deep, you can water. If the plants are drooping, you can water them.

How—For mature plants (and vegetative plants), fully soak the soil so that water runs through. Get even the deepest parts of the soil wet.

Measure—keep track of your watering schedule! Write it in a log so you can effectively watch your plant’s growth over time and know how your plant reacts to different watering stages.

How do I know if I’m not watering correctly?

What are the signs of bad watering? Your plants will tell you. Check the leaves: If the leaves are wilted, curling, turning yellow, light, or crispy, you’re underwatering. If the leaves are soft, limp, fat, drooping, or floppy, you’re overwatering. The leaves should stand straight out and be proud of their shape. Cannabis plants are very communicative about how they’re feeling, just watch them.

overwatering vs underwatering-How often to Water Cannabis

Weigh the pot: If you’re very clever, you’ll weigh the pot when the soil is dry and weigh it again after watering—when the soil has absorbed enough water. You will know the weight differences before and after watering. Regularly weighing your pot can help you to decide when to water.

Stick your finger into the soil: You can also know when to water by checking the state of the soil—poke one finger about 1-2 inches into the soil. If the soil feels dry, it’s time to water.

Factors that affect watering-How often to Water Cannabis

  • Pot size: You’re commended to provide the proper pot or grow bag for your plants. You can start germinating seeds with small pots since they prefer less water in the seeding stage, and then upgrade the pots according to their growth. Make sure your pots have good drainage, there is a hole at the bottom of your pots—the extra water will drain out naturally. Be aware, if water can’t drain out it will take a long time to evaporate and you’ll be more likely to grow mold or attract pests. Standing water causes a number of problems, including root rot and fungus.
  • Growth stage: The need for water increases with the growth of cannabis. Keep observing your plants, they will tell you if they need water or not.
  • Temperature and humidity: This is easy to understand. The higher the temperature, the faster the evaporation, but the higher the humidity. Conversely, the lower the humidity level, the slower the evaporation and the lower the humidity. When growing cannabis, your temperature range will not be too large, but it is something to keep in mind. You might need a hydro-thermometer to test these two data.
  • Medium: The soil type will also affect watering. Perlite and coco coir are widely used media. Perlite is acidic lava rock from volcanic eruptions that can absorb 2-3 times its own weight in water. Therefore, perlite is often added to the soil to help drain excess water. Coco coir is a natural fiber extracted from coconut shells and is also used to increase the water retention capacity of the soil. Both of these change how often you’ll need to water and cut down on the risk of overwatering and root rot.

Watering is not as easy as it looks. You need to consider a lot of factors but luckily the tried and true method of knowing when you need to water is simple: stick your finger into the soil, if it is dry then you can water. But, if you want to get scientific, the frequency and amount of watering can be calculated carefully—you’ll get much better results this way.

Make sure you’re tracking all of your watering throughout the growth cycle of your plant, and watch how your plant reacts, so you’ll know how to alter your schedule to fit your plant’s needs. Your plants will reward you if you water them properly. When you see the resin on the buds, it’ll all be worth it!

If you have any questions, please don’t hesitate to reach out to us!

And be sure to check out our other blog posts for useful tips on becoming a great grower!

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  1. My plant was growing well outdoors but when it started to get to flowering it began wilting. I was watering every 1 or 2 days and then it came back. I’m in SoCal so maybe it was the heat.

  2. I bought a bag of seeds from a friend a while ago and started growign them about a month back. I’m trying to follow the best watering schedule but the plants look different and two are what you described as being overwatered. can you help me whats going on

    • Seeds from the same mother plant can have slight genetic variations that can cause their environmental preferences to vary. It’s not surprising that you’re seeing these differences–just keep close watch of each plant individually and feed and water them according to how they respond. Luckily cannabis is super communicative so it won’t be tough! Good luck!

  3. Definitely have made the mistake of overwatering when I first started! Good advice to new growers out there (I know you’re lurking)


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