Watering Weed
A Guide To Water your Marijuana Plants

The importance of H₂O

Cannabis plants, like most living things, consist largely out of water. Needless to say that maintaining that water balance is of vital importance.

Watering cannabis is a science in its own right. You will be dealing with meticulous PH values, various types of water as well as fluctuating needs during different life stages.

Overwatering could lead to nutrient deficiencies and diseases while providing too little water is often the reason for stunted growth.

It's a delicate equilibrating that you need to maintain at all times in order to get that thriving crop every grower desires. Don't let this discourage you though, we are here to walk you through how to water cannabis every step of the way.

What is the right temperature to water your plants?

Aside from the pH and EC levels, the third most important factor is your water temperature. If there are wide fluctuations in temperature, this may lead to problems along the way. Water that’s too hot or cold will not be able to absorb certain nutrients.

When growing in soil the perfect temperature is between 20 and 23 °C, keeping in mind that the soil acts as a sort of wall between the inside and outside, which allows for slight variations in the temperature in your grow room and water.

By using a simple thermometer you ensure your plants get watered at the correct temperature.

There are a plethora of different water thermometers available, most of them pretty affordable. Some EC and pH meters can also measure water temperature accurately. Depending on the temperature, water can actually suffer certain changes in its composition, including oxygen levels.

How often should you water your plants?

How much water your plants need and when it is time to water, depends on various factors. One of them is the life phase of the plant. For instance, seedlings and clones have a much lower water requirement than vegetating and flowering plants.

Let's look at the individual stages

• Germination: One of the basic things in seed cultivation is that you need to make sure to keep seeds damp but not wet. This generally means you need to water them once per day. Using a starter tray is a great option since the plastic cover works well to contain heat and moisture. Another solution to ensure the soil remains moist is to cover your container with plastic wrap.
  
  
• Seedling: Seedlings are delicate and require appropriate care. Be highly meticulous and always provide them with the right amount of water. A frequent error a lot of growers make is providing them with too much water. Overwatering the seedlings in this precarious phase can "drown" them since their roots are not receiving any oxygen. As a result, this ends with the untimely death of your seedlings. Maintain the course you set on during the germination phase. Keep your seedlings moist but not wet. Make sure to never let them dry out completely either! Water the soil for your seedlings at least once per day as needed. A plant sprayer is an excellent way to water your seedlings while keeping the soil moist without letting it get too wet.
  
  
• Vegetative: Plants in the vegetative stage are up for a true growth spurt. Obviously, they need enough water to thrive. You water weed depending on your pot size, I advise at least one watering per day for small pots. If you are using larger pots, increase that to twice a day.
  
  
• Flowering: Watering during the flowering stage is a crucial moment. Typically, large flowering plants need water at least once every 2-3 days. Determine when it is time to water by testing the moisture level. It should feel dry on top, but still, somewhat damp below the surface. If it remains dry to the touch at depths of more than 5cm or so, your plants are probably too dry and would love to get some additional water.

How much water do marijuana plants need?

How much water your plants need depends on a number of factors, including:

• Outside temperature
• Stage of growth
• Size of the plant

Larger plants will require more water than smaller plants. If you’re growing the plants outdoors, provide them with more water when the temperatures are up, and make sure to reduce the amount of water when the humidity level is high.

Water should pool up on the surface of the soil while you’re watering, but it shouldn’t sit on the surface after you move on to the next plant.

If a plant is very dry, water will run straight through the pot and quickly come out of the drainage holes. When this occurs, water the plant a little, move on to the next plant, and repeat after 10 minutes as necessary. This allows the soil to gradually absorb water incrementally until all of the soil is thoroughly wet.

As the plants' lifecycle progresses, so will their need for water. You might want to provide some individual plants with additional water in between their main waterings as they grow.

Take notes and make calculations. Setting a cycle where the plant needs to be watered every two to three days is ideal. As you continue your growth you will eventually come up with the perfect watering schedule for your plants' needs.

How to tell if you are underwatering cannabis

Wilting is the first sign your marijuana plants are in desperate need of some additional H20. The cannabis leaves drooping will seem limp and lifeless and, in worse cases dry or even crunchie. It is of the essence to take action now because this condition will inevitably kill your plants if not corrected at once.

How to tell if you are overwatering cannabis

Overwatered your cannabis plants can be just as harmful as underwatering them. Overwatered cannabis plants are droopy with leaves that curl down. As a result of overwatering, leaves often turn yellow or show other signs of nutrient deficiencies (Particularly younger plants and seedlings are very sensitive to this).

When your plants are showing signs of overwatering, this does not necessarily mean you need to give them less water but rather to adjust the frequency of watering and make sure your growing medium has proper drainage.

The best method for watering weed

Instead of watering your plants in small quantities multiple times, try giving them a less frequent but efficient soak. 

A proper soak implies watering them to 25–33% of the pot's capacity. This amount provides the root system with sufficient water to quench its thirst, without excess puddling and potential fungal issues.

When watering, you want to start in the middle first. After allowing the roots to breathe, continue watering the edges of the container too. This way the root ball also transports nutrients residing in the top of the medium down to the root system below.

This results in the correct amount of water minus the hassle of possible puddles. This is especially beneficial to avoid fungal pathogens that lead to root rot, which are often caused by excess water. 

Besides creating holes at the bottom of your containers allowing the water to escape from, the containers should be lifted slightly off the ground, allowing the water to drain and plants won't be left in puddles of moldy water. 

Why the right pH value is key

When growing in soil, the pH range of your water should ideally have a pH value of between 5.8 and 6.5

To test your water pH, you can a measuring stick or some pH measuring drops. If the pH is too high or too low, you need to adjust this. Using a few drops of pH up or pH down to reach the right level. This is especially important if you’re using tap water which generally has a higher pH.

If you do not have this ready-made formula at hand, don't worry! There are other ways to get the desired ph level.

Lemon juice has high acidity and a pH between 2.0 and 3.0, so when you add a few drops to your water, this will certainly lower the pH. Appy, as needed until achieving the result you want.

Baking soda does exactly the opposite. This multifunctional substance, also known as sodium bicarbonate, is naturally alkaline and has a pH of 8. When adding baking soda to your water, you will raise both the pH value as well as the alkalinity.

A word of advice: If you’re adding cannabis nutrients to your water, measure your pH after each feed. This will provide you accurate information for future growths (make sure to add this data to your growth diary). And on top of that, it will tell you if you need to increase nutrition or modify the next dosage.

Watering weed in a nutshell

Well, sorry for this lengthy narrative, there is just so much to tell!

After going through the various different types of water you can use when growing cannabis, including some you may not have thought of, the best water for growing plants is clearly reverse osmosis or distilled water. These two types of water can guarantee that your plants aren’t getting any toxic minerals or anything they shouldn’t get unless you’re adding it to the water.

Make sure your soil never completely dries out and always, always check your PH values before watering weed. Hopefully, you will never feel like a fish out of water again when it's time to water your marijuana plants ;-)

Happy growing!