How Much Water Does a Cannabis Plant Need?

Table of Contents

  • How Do I Know If My Marijuana Plant Needs Water?
  • How Often Should You Water Your Cannabis Plants?
  • How To Water Your Marijuana
  • What are some common problems associated with watering cannabis plants and how can you avoid them?
  • Conclusion
  • Frequently Asked Questions

This is a very important question and a big part of proper cannabis cultivation. Alas, there is no simple answer.

The needs for growing healthy plants vary greatly as many factors have to be taken into account.

The plant has different phases, the growing medium you use and the external influences combined create a big difference in the thirst of your plant. You have to feel the soil, learn to read the plant, and know what to do.

inspecting soil

Ideally, you will be able to create the right balance when watering your cannabis plants; neither too much nor too little. Too little will slow the growth and decrease the plant size, and too much water will take its toll in various ways, none of them good. You’ll need to find that sweet spot and we will help you to do so.

Creating the optimal environment will minimize stress on your weed plants and allow them to be able to focus all their energy to grow and create those gorgeous buds for us. It takes some effort and getting used to, but we are confident that you will become a water management specialist!

What are the factors you have to take into the calculation?

  • The climate of where you live
  • In which Stage Of Growth your weed plant is
  • Growing medium and the container


how much water to give your plant

Where you live will affect how thirsty plants get. If you live in Death Valley in The United States, the hottest place on earth at 45°C (113°F), your marijuana plant will need more water, than if you lived in the village of Mawsynram in India (the wettest place on earth with 467 inches of rain per year!).

The relative heat, humidity levels, sunlight, and rainfall in your area will affect the watering frequency of your cannabis plants.

If you are growing cannabis indoors, you have more control over these elements.

That’s why many growers prefer indoor growing. It’s more stable and easier to be regulated, with fewer distractions making it give exactly what the plants need. Also not unimportant; many people prefer indoor-grown cannabis above outdoors.

The Stage Of Growth in weed plants

Which phase and how old your cannabis plants are will also affect the amount of water they need. Simply put: a seed under the soil has lower water demands than a fully grown plant. The smaller seedling does not have the mass, yet, that a fully grown plant has.

cannabis seedling stages

A sprouting plant needs more water than a seed, but less than an adult plant. Again, there are size issues at play here. At certain stages of growth, the plant will require more or less water than it did the day before.

So how can you tell if your plant needs more water or less water?

Well, there are a couple of ways to figure this out.

Growing medium and the container

If you’re growing cannabis in soil, you need to be especially careful not to overwater your plants. Soil is great at moisture retention, but it also drains quickly, so get your hands dirty and check regularly.

watering soil

Hydroponics systems rely on a constant supply of water, so if your plants start to show signs of drought, they may not recover.  So keep your eyes open and check the level of the reservoir regularly and top up as needed.

So every grow medium has its pros and cons, the container you use or the casing you have built should balance out the cons. Making it the perfect match for growing your marijuana plants.

How Do I Know If My Marijuana Plants Need Water?

dry cannabis plant

Your plant will most likely tell you if it needs water. There are two simple tell-tale signs:

  • The first sign that a cannabis plant is starving for water is when it begins to sag and droop. This is your plant’s way of telling you that she is in need of water. Water your plant immediately if you see this.
  • You can check your grow medium. Stick your finger about 5cm (or about 1-2 inches) under the surface, and if it’s dry give your plants water.

A third is for the more experienced grower:

  • Marijuana plants tend to grow more slowly when they are drought-stressed, so if your plants are not growing as quickly, as usual, they may need more water. By keeping an eye out for these signs, you can ensure that your marijuana plants stay healthy and happy.

If you have mastered the skill of how to water plants, the leaves will be nice dark green, the color we all know and love. We salute you!

How Do I Know If My Marijuana Plant has too much Water?

outdoor cannabis plant in the rain

A plant that has brown leaves or yellowish may have root rot. This occurs when you have watered your plant too much and its roots have begun to rot.

This can also happen when your pots or casing have too few or clocked drainage holes, causing little to no water runoff. And causing a level of standing water on the bottom drowning parts of the plant’s root system.

For beginner cannabis growers, we advise keeping detailed notes. You can learn from these and apply the notes to later grows.

But keep in mind, this is not an exact science, it’s nature! Every plant, every grow is different, watch your plant for what it is doing. It will tell you when something is off.

How Often Should You Water Your Cannabis Plants?

best time to water cannabis plant

We recommend daily, easily done with an irrigation system on a timer, but more a challenge when you water by hand.

You might be going out one day, this does not have to be a disaster straight away. You do have a bit of wiggle room. If you know you won’t be able to water it tomorrow, you can add some extra today. Then when you are back the day after tomorrow you have to check the soil, and if it’s in normal range resume your normal water scheduling.

We will elaborate on the most common situations to give you a bit more insight.


If you grow your weed directly in the soil, you will have to monitor how your soil behaves. If the soil dries out quickly, it means they don’t get enough water. You will need to water the plants more often.

If the soil remains damp for longer than 3-4 days, you will need to look at the soil to see if it is too compact. You may also want to make sure that the water runoff and draining properly works. 

Find the right balance for good soil. Learn from your personal experience and become consistent.


If you grow your marijuana in a pot, it is easier to keep an eye on the dryness of the soil.

watering cannabis plants

You can get into the pot and see how the soil is doing. Also, you control when they are watered. So the chances of them being over-watered are less likely – if you are being consistent.

Some pots are breathable and allow moisture to evaporate out of the sides. I am thinking about terracotta pots and unglazed clay pots. Other pots will trap moisture, this can happen with plastic pots. Watch your soil to make sure it isn’t too wet or too dry.

Never wait for the soil to get dry to water your plants. I think it goes without saying that if the top of the soil is still wet, you do not need to water the plants.

Super Soil

super soil

Super soil is a potting mix with organic nutrients added to the soil. 

You will need to prepare well in advance as it can take up to 6 months for the organic matter to dissolve and create your super soil ecosystem.

Super soil has its manual as it quickly has enough water and only requires watering 2 to 3 times per week.

How To Water Your Marijuana?

There are a few different ways to water your marijuana plants, depending upon how many plants you want to grow, and where you are growing.

The two most common ways are:

  • Watering can. The classic, simple method
  • The Irrigation system. A bit more expensive, but has many perks.

watering plants

The Watering can

This method is too much work if you grow in large quantities. But if you are just starting growing marijuana, chances are you will only be growing a few plants. 

So if you only have a few plants, the ideal tool for your cannabis is a watering can. A watering can allows you to water the soil and then the leaves – if they are out of direct sunlight.

However, it has its drawbacks. You may need to fill it multiple times depending on how many plants you have, and adding nutrients is a challenge. Also, the amount of water the plant needs goes up as the plant gets older so more and more runs for you. However, it is still a good, simple, and cheap way to water cannabis.

The Irrigation system

From our personal experience, we would recommend an irrigation system with a basin. If you have the budget of course!

There are many benefits to growing cannabis with an irrigation system:

  • Timer. A tight schedule, every day at the same time, no days missed. You can set how much water it will dispense giving exactly what the plants need every time. You do have to update the levels when your plant goes into a new phase.
  • Scheduled time. You can water the plants at night-time without any disturbance, and prevent any chance of burned leaves from water drops.
  • Water temperature. A Water basin will keep the water at room temperature
  • Pre Mix. you can make a basin full of all the nutrients required for multiple days at once
  • Reachability. the system can reach the lower parts of the plants
  • Drip Irrigation. You can decide to do drip irrigation, and create a steady flow. Or schedule a once-a-day shower.

These give your watering schedule a perfect consistency, water quality, stable PH level, dosage, timing, and set frequencies. A relaxed way of growing weed, as you can sit back and watch your beauties grow!

What are some common problems associated with watering cannabis plants and how can you avoid them?

plant diseases

  • In a rotting root system, the roots will have colored dark brown instead of the ivory color they normally have. Invest in pots with good drainage holes and check them after each harvest. Still and excess water on the bottom of your pot (or casing) will cause this.
  • Burned leaves. If you water your plants while they are in “daylight” the water drops can function as a magnifying glass and burn the leaves.
  • With discolored leaves, the plant may not receive the right nutrient requirements, the PH level is off, or it is an indicator of root rot.


As we have mentioned earlier, the right doses of water will prevent stress and create healthy plants. The amount that is enough varies because of many different factors. Like combinations of the soil, growing medium, plant phase, and the climate where you live.

grow basics

Reading your plant’s needs is a skill you have to master so that you can adjust the watering schedule accordingly to the situation and thus create optimal environmental conditions.

The better you become, the bigger your harvest so it’s worth your time!

Are you ready to start growing some cannabis plants of your own? Be sure to follow our tips for watering and you will be well on your way!

Frequently Asked Questions

How Important Is The Right Amount Of Water For Cannabis Plants?

Uttermost important! Water is the giver of life, true in all of nature and when you grow weed! In the right amount, you will be able to grow healthy crops and big yields. Too much water and you’ll hurt the plant, too little and you will slow the growth. It’s a delicate balance that you have to find.

What’s The Ideal Temperature For Watering Cannabis Plants?

The ideal temperature for watering your plants is room temperature. Hot or cold water can stress your plant, and in some cases, even kill it. That’s why it’s important to let the water sit for a while before using it on your plants. This way, you give the water time to reach room temperature.

Can I Use Bottled Water To Water My Plants?

Yes, If your plant is a model that only drinks a certain brand of water, we must oblige. You can use bottled water to water your plants, but, depending on the water quality where you live, this might not be the best water source.

That’s because some brands of bottled water contain high levels of fluoride and other minerals that can damage your plants.

no water bottles

If you do use bottled water, be sure to check the label to make sure it’s low in minerals. For growers living in countries with drinkable tap water it is easy; what is good for us, is good for the plant!

What Are The Different Ways To Water Cannabis Plants?

The most common way to water cannabis plants is with a watering can, hose, and an irrigation system. Whichever method you choose, just be sure to water your plants at the base of the stem and not on the leaves. This will help prevent leaf burn.

What Happens If I Overwater My Plants?

If you overwater your plants, you cause them stress and you run the risk of root rot. This is a serious problem that can kill your plants. To prevent it, be sure to water only when the soil is dry to the touch. And, if you do overwater, be sure to drain the excess water from the pot immediately. You don’t want to lose your harvest!


You May Also Like