How Much Water Does Your Plant Need?

Beginner Grow Guide is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to If you click on a link on this site that takes you to Amazon, I will earn a small commission and help keep the lights on at no extra cost to you 🙂

Growing weed in the traditional sense, in soil outdoors or indoors, remains as the most popular method for home grown cannabis. While hydroponically growing can provide strong and quality plants, the tried and true methods of soil based growing will remain omnipresent within the landscape of the cannabis growing community.

While you may assume that watering your plants is one of the easiest steps in the growing process, it also carries the biggest risk of unhealthy growth if improperly implemented. While outdoor growth may come with a more hands off approach, with the soil receiving natural water supplementation, indoor growth can prove to be more tricky if you are a new to growing cannabis.

We’ll break down how much watering you should be doing of your plants, and the various tricks and tips to keep your plants satiated throughout the growth process.

How Much Water Should I Be Using?

For soil based plants, it can be a bit of an experiment to figure out much water you should be providing on a regular basis. As a loose rule of thumb, you should be watering about 25% of your total soil capacity.

For example:

  • 1 Gallon Of Soil – ¼ Gallon Of Water
  • 2 Gallons Of Soil – ½ Gallon Of Water
  • 3 Gallons Of Soil – ¾ Gallon Of Water
  • 4 Gallons Of Soil – 1 Gallon Of Water
  • 5 Gallons Of Soil – 1 1/4 Gallons Of Water

You may find that using more or less water will be effective depending on your specific strain, plant size, and environment. This water should be spread evenly over the soil, using 2-3 light passes with the water to avoid over saturation.

 How Much Water Does Your Plant Need?

Similar to not having enough water for your plants, providing too much can be detrimental to your plants ability to absorb nutrients effectively over the course of the growing cycle. In addition, too much water can cause overly humid growing conditions, which allows for easier fungal growth and subsequently putting the health of your plant at risk.

How Do You Know When To Water Your Plants Again?

Knowing how often to water your plants will be more of a nuanced process, with each plant absorbing the water at its own pace. In general, your plant will need to be watered once every two to three days, however this may change throughout the growing cycle or due to environmental conditions.

Weigh Your Plants

The easiest method to figuring out whether the plant has fully absorbed the water will come down to the weight of the pot and plant itself. Once the water has dried throughout the soil, it will reach its original weight before watering.

You can measure this with a scale or simply by hand, lifting the pot and comparing it to the weight of a pot of dried soil.

Monitor the Soil And Plant

By simply monitoring the saturation of your soil, you can determine whether it is time to water your plants again. Sticking your finger into the center of the soil a few centimeters deep can provide a decent indication of how dry your soil is, however this will not speak to the deeper soil.

Water management and plant care

There are also indications through the plant itself, displaying signs that it is craving more water. This is apparent with leaves displaying unhealthy colors and becoming misshaped.

Be on the look out for these indicators:

  • Yellow or brown leaves
  • Drooping branches or leaves
  • Dried and frail looking leaves

Should I Be Watering At A Specific Time?

Once you have figured out how often your specific plant requires watering, the next step would be to dial in the watering process. It is best to water your plants before hours of sunlight (for outdoor growing) or the beginning of your daily indoor lighting cycle.

This will prevent the water from over saturating and growing mold or fungus during the darker hours, with any excessive water not being absorbed until the plant is exposed to light. When it comes time to water, apply the water lightly and evenly from the center of the soil in a circular motion outwards in multiple passes for even saturation.

Tips For Preparing Your Water

Because the pH levels of the soil and water are important for effective nutrient uptake, understanding the natural pH levels of the water you are using can save you the hassle from skewing the balance within the soil.

Clean water (healthy concept)

Once you have sourced your water, with even something as simple as tap water being sufficient, let it sit for around 24 hours to settle the pH levels. You can then test these levels with strips or your own meter, aiming for around a pH level of 6.

If this level is off, there are various pH additives to balance out these levels.

Other Factors To Consider When Watering Your Cannabis

Container Size

As mentioned above, the amount of soil in your container will be the biggest determining factor when it comes to the amount of water you need for proper saturation. Additionally, the depth, drainage, and shape of your container can all affect how much water you can apply at once as well as whether the roots can properly spread and grow.

The Growing Environment

Setting aside outdoor growth, which will have a more complex and nuanced process depending on the weather, amount of daylight, humidity, and many other factors, indoor growers will also have to consider their own environments when it comes to watering their plants.

Marijuana flower blooming medical cannabis plant

Keeping your indoor humidity at an appropriate level to avoid mold and fungus, while also not drying out your plants will play a role. This also includes the temperature, with hotter grow rooms causing the plants to dry out quicker under heavy lighting or substandard ventilation.

Soil Type

There are a number of different soils you can choose when growing your own cannabis. While some of these may be suited better for indoor or outdoor growth, certain strains, or specific growing setups, they will all have their own effect on the watering process.

The biggest variable will be the natural pH level in the soil, with the watering process affecting this considerably. Because the pH levels are easily monitored, keeping the levels of your water and soil cohesive for proper nutrient uptake should be relatively straight forward.


With proper monitoring, the watering of your cannabis should be fairly straight forward. As long as you are well aware of the saturation of your soil, the visual health of your plant, and the appropriate pH levels of your water and soil, there shouldn’t be too many roadblocks in the process.

Adjust all of these factors as needed and the result should be a healthy and potent plant.