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how often do you water cannabis seeds

How Often Do You Water Marijuana Plants: Answered

If you are just starting to grow your own marijuana plants for the first time, you probably have some questions that you want to ask.

One very important growth factor when it comes to pot plants is watering, both how much and when. So, how often do you water marijuana plants?

Well, some plants need to be watered every single day, and some only need to be watered every 2 to 4 days. The point here is that there is no exact rule when it comes to how often you need to water your cannabis plants.

There are various factors which will go into determining this, and we are here to look at the most important ones today.

How Often Should I Water My Indoor Weed Plants?

Something you need to know is that watering your weed plants, especially in terms the quantity and how often to do it, is not an exact science by any means.

Some marijuana plants may need to be watered each and every single day, whereas others may only need to be watered ever 2, 3, or 4 days.

The point here is that there are a variety of factors which can affect how often weed plants need to be watered, so let’s talk about each of these right now.

Factors Which Affect The Marijuana Watering Schedule

Generally speaking, there are 6 main factors which are going to determine how often your marijuana plants need to be watered, so let’s take a closer look at each of these factors.

1. Stage Of Plant Growth & Size

One of the first factors to keep in mind when it comes to deciding how often to water your weed plants has to do with the size of the plant and what stage of growth it is in.

For example, a young seedling does not have a large root system, it is not very large, and its water requirements are not too heft, so watering it every 2 days, or even every 3 days, is probably more than enough.

However, if we are talking about a large marijuana plant that is well into the vegetative state, and more so, in the flowering state, is going to guzzle down much more water, and therefore probably needs to be watered every single day.

Simply put, the larger the marijuana plant, the more water it is going to consume.

2. The Planting Medium Being Used

One of the other biggest factors that is going to determine how often your weed plants need to be watered is what kind of medium you have the planted in.

There is a bit of a trade off to keep in mind here, because pot plants do like growing mediums which are fairly fluffy and have good drainage.

Having good drainage is important because if the soil holds water for way too long and it never dries out, not even a little bit, then things like fungus, mold, and root rot can occur, all of which can put your weed plants in serious trouble.

However, on the other hand, really airy and fluffy soils and growing mediums do hold water for longer.

It’s a good idea to have a mix of high quality and dense potting soil, together with a bit of pearlite and coco coir for drainage (if you need some good suggestions, then check out this article).

If you have this, chances are that watering your weed plants every 2 days will be more than enough. Just keep in mind, you need a good mix between drainage and water retention.

3. Temperature, Humidity, & Light Intensity

The next set of factors which is going to affect how often your weed plants need to be watered has to do with the temperature and humidity of the grow room, as well as the light intensity too.

The stronger your lights are, the faster the weed plants will grow, and the more water they will need. Moreover, more intense lights usually also lead to higher grow room temperatures.

There are also other factors which can affect grow room temperature, but the point here is that the hotter it is, the more water the weed plants will need.

This is in part because the hotter the air is, the more water will evaporate out of the soil, and therefore the soil will require replenishment more often.

A hot grow room with lots of strong lights will make you have to water the weed plants more often.

4. The Overall Health Of The Weed Plants

Another factor to keep in mind here is the overall health of the marijuana plants. Very healthy plants will grow quickly, and therefore need more water.

An unhealthy plant with slow or stunted growth will require much less water.

5. Ventilation & Airflow

Yet another factor which goes towards determining how often your weed plants need to be watered is how well ventilated the grow room in question is and what kind of airflow you have going on.

Now, this is not always a solid rule or law, but chances are that if you have a very well ventilated grow room with lots of airflow, there is going to be a lot of moisture carried away due to that airflow, and therefore your weed plants will need to be watered more often.

Keep in mind that the overall airflow in your grow room is also going to affect the temperature and humidity levels, which as we covered earlier in this article, also affect how often your weed plants need to be watered.

Telling If Your Marijuana Plants Need Watering

We do have another full article for this topic, telling if your marijuana plants need water or not, but it is important to mention, so let’s just do a quick overview here.

There are a couple of easy ways to tell whether or not your pot plants are thirsty;

Is the soil bone dry or does it stick to your fingers? Stick your finger in the soil, and if the top inch of the soil is dry, the pot plants probably need some water.

If the soil is very moist, even to the point of sticking to your fingers, then you should wait to water them.

Plant Look

How do the plants themselves look? Most often, brown, dry, and shrivelling leaves are a pretty good indication that your marijuana plants are not getting enough water.

A Soil Monitor Is Your Friend

A very simple way to tell if your weed plants need water is to purchase a soil monitor which can inform you of the moisture content in the water.


When all is said and done, as, you can see, there are a few different factors which will determine how often your weed plants need to be watered, as well as various ways to tell whether or not they need water.

Just remember, both too little and too much watering can come with some pretty serious consequences, so be careful!


My passion for the sticky icky started nearly a decade ago, and it all began when I first laid my eyes on the beauty that is the marijuana plant.

I cover all aspects of growing from equipment recommendations to plant health/care tips to help both new and experienced growers.

Seedlings: How often do you water, or how do you know when to water?

This is my first grow. I have 3 little baby girls. My question to you guys is how often do you water, or how do you know when to water? I have read that seedlings will die if they dry out. Does that mean at this stage I have to keep their soil moist at all times? Or now that they're this big do I treat them like vegetative stage and let the soil completely dry before watering again? I ask because the one in the front hear is leaning over weird today, but that may be explained by her reaching for another light I have on the edge of my crappy grow light. Would it flop over if it was thirsty? These girls are going outside as soon as it's warm enough. Soon they will go in pots in my sunroom, and then mid-June once it's nice and warm they'll go outside.

How to properly water marijuana in every situation

Have you been growing cannabis for a short time and still don’t fully control how often and how much water your plants need? Do you want to install an automatic irrigation system and do not know how it works? Do you have to leave the house for a few days and are worried about the risks they need? Well, you have come to the most appropriate place, because in this article we will look at the best way to water marijuana plants in different situations.

⚠️ Irrigation of cannabis, wet-dry cycle, an important balance

Irrigation is essential for the maintenance of plants of any type, and although marijuana can be considered as a weed that grows everywhere, it is important to control certain aspects of irrigation for optimal development.

Irrigation is the way in which plants feed through the roots, because it allows the cationic exchange between the root system and the soil, which releases nutrients thanks to water, a chemical roll that we will not go into further due to how much be boring. . The important thing is that you know that the substrate cannot always be humid, because the roots also need oxygen and because if no air enters, fungi can be created, so the ideal is to respect the wet-dry cycle.

Between waterings it is essential that the substrate dries up, not completely because you don’t have to wait for the leaves to fall, but unless it allows oxygenation, and how do we know if it has aired or not between a watering and the other? There are several ways to find out, and it depends on the type of crop, but what you need to be very clear about is that roots need nutrients and oxygen for plants to develop perfectly.

Image of the wet-dry cycle of cannabis *

How to water your cannabis plants in the best way?

The action of irrigation is simple, providing the water or nutrient solution to the plants, but is it still worth it? The answer is no. We must try to moisten the substrate little by little, making sure that the water reaches all points. Some gourmets water with a pressure sprayer to make this action as slow and smooth as possible, but it doesn’t take long, just go little by little, never right away.

There are also people who prefer watering by flooding, that is, instead of watering the top of the substrate, what they do is flood the tray or dishes where the plants are, and the soil absorbs moisture from the bottom up. Flood irrigation is very convenient, but it has the disadvantage of being dangerous for the possible formation of fungi.

How to water marijuana at home?

Indoor cannabis cultivation has more followers every day, consumers who start self-cultivation to be able to cover their offer without having to resort to the black market. Nobody is born knowing, and one of the first problems we encounter when we start this task is…How should we water? How much water? How long should I wait between irrigation and irrigation? Don’t worry, we’ve all had these doubts, but luckily you have this information at your fingertips.

First of all, we need to distinguish between crops land, coir, hydroponics and aeroponics, because each system has different needs. Most new growers start with pots and potting soil, as this is the most widely used and probably the simplest medium

Manual of marijuana grown with indoor soil

When the plants are small, we recommend watering with a watering manual , in this way we make sure that the soil is not too soaked and that there are no areas without humidity. Once the seed sprouts and sprouts from the ground, it can be watered around the stem of the plant, leaving the perimeter of the pot dry to ensure that the substrate continues to oxygenate. As the plant grows we will increase the amount of water, until the moment in which we will have to water the entire surface of the pot, and from that moment we will wait for it to dry before watering again.

Another way to know the amount of water in the substrate is with a Rapitest 3 in 1which, in addition to checking the humidity, measures the PH of the soil to know if it is in the correct values. Some growers stick a finger into the substrate to see if it’s dry or wet, but that’s not a good way to say it, as many times the top is dry but the rest is still wet.

How to water a marijuana plant outdoors?

In outdoor crops, all processes are slower than in indoor crops, the season is longer and the days usually do not have as many hours of light as those we report indoors. That same pace needs to be adapted to risks and also take into account other issues such as environmental parameters.

We normally use larger pots outdoors than indoors, but plants also get bigger as a general rule. When the plant is small but the pot is large, try not to wet the substrate too much, better proceed slowly as we have seen before, watering around the main trunk and widening the irrigation diameter every time we water, until we get wet . Earth.

The water requirements of outdoor plants are different from those of indoor plants, and above all more variable. Inside we set parameters that remain stable, but outside the temperature, humidity, incidence of light and other factors change every day, so we have to adapt the irrigation according to the weather. Rain counts as irrigation, and the dew of the night is also absorbed by the leaves, so we can save some watering.

How to water marijuana plants planted in the ground?

If the plant is on mother earth, it does not have many problems with moisture accumulation, but it is still better to adapt the frequency and quantity of watering to the size of each specimen. A plant more than 2 meters tall planted directly in the ground may need more than 10 liters of water per day, but in reality some of it evaporates due to the heat or gets lost in the lower layers of the substrate.

That’s why the best way to water large outdoor plants placed in mother earth is with automatic watering, so you don’t have to prepare watering every day and you can’t worry. Automatic watering is also ideal for other situations, such as when you leave the house for a few days or for some reason you can’t keep an eye on the plants.

How to water the plants on vacation? Installing an automatic drip irrigation

You may be wondering how to water your plants without being at home, such as when going on a business trip or vacation. In this case, as with large outdoor plants, the best thing to do is to install an automatic irrigation system.

If you have fresh running water in your area, you can directly connect an automatic irrigation programmer, one of those that are installed right under a tap. In this case, you need just to adjust the times of day you want to water and the time of each of these waterings.

If, on the other hand, the water that comes out of your tap is too hard, the ideal is to use osmosis water or at least eliminate the limestone and chlorine that the plant cannot assimilate. In this case, you can fill a drum or tank with good water, add the corresponding fertilizers at each stage and finally correct the PH. Once this is done, a pump is inserted to which a flexible tube is connected, and in this tube we can place the drippers that we will put distributed around the trunks of the plants.

How to remove lime from water and chlorine to water plants in the best way?

Part of the chlorine present in the water evaporates at room temperature, just leave it in an open container for about 24 hours. This is done by many growers in order to irrigate with tap water, even if you never know to what extent the problem has been solved.

But to remove limescale from the water that method is no longer valid, in this case you need a softener, or directly a reverse osmosis system, which leaves the water with an EC of 0 or 0.1. Since osmosis is used, the membranes or filters must be changed, as they lose their effectiveness over time.

✅ Other important questions to consider before watering your cannabis plants, PH and EC

It is useless to have the best irrigation water with the best nutrients if you do not correct its PH. The PH is the potential of hydrogen contained in the water, it oscillates between 0 and 14, where 7 is the neutral value. The ideal pH of the irrigation water varies according to the cultivation system and the phase or time in which the plants are located, but normally it remains between the margins of 5 and 7.

EC or EC stands for electroconductivity, that is water water ability to conduct electricity, although for us the important thing is that this is how we measure the quantity of dissolved salts contained in the water, that is, the quantity of food when these salts are assimilated by plants.

To prepare the marijuana irrigation well, you need to start with a soft water base, add the products corresponding to the phase in which the plants are, adjust the PH and, if you want to curl the hedgehog, put it at a temperature between 20ºC and 24ºC. If you want to know more about the PH and EC of marijuana, I recommend that you read this article in which we detail everything much better.

Image of a graph where you can see the assimilation of nutrients depending on the PH of irrigation *

How much water is needed in each irrigation?

This depends on many factors, such as the size of the pot, the temperature and relative humidity of the environment, the variety, the size of the plant, the phase in which it is, etc. but I will tell you that is just the right amount needed to wet all the substrate and drain a little through the bottom holes of the pot. Below you can see a list with the approximate quantities needed for each volume of :

  • Pot to 0,5 liter : 50 ml. of water
  • Pot to 1 liter : 100-150 ml. of water
  • Pot to 3 liters : 300-400 ml. of water
  • Pot to 7 liters : 700-800 ml. of water
  • Pot to 11 liters : 1-1,2 liters of water
  • Pot to 15 liters : 1,4-1,7 liters of water
  • Pot to 25 liters : 2,3-2,7 liters of water
  • Pot to 50 liters : 4,5-5,5 liters of water

White round pot. White color is an ally against overheating of the roots….