Buy Quality Marijuana seeds at Amsterdam Seed Supply – How often should you water Marijuana Seeds? – ✓ High Quality Strains✓ Award winning genetics Water plays a crucial role in keeping your marijuana plant healthy. Get tips from the experts at Leafly to keep your weed plants hydrated, and learn how to flush them properly. You probably never thought about it but watering weed is a science on its own. Here are all the ins and outs of how to water like a pro.
How Often Should You Water Marijuana Seeds?
After the hassle of choosing a seed and getting it to sprout then grow, another of the big questions is how often should you water marijuana seeds until they germinate. You should not water marijuana seeds once you place them to germinate in a warm moist place. If you give your marijuana seeds water very often you will drown the seedling and it won’t be able to crack out of its seed.
Now that the Marijuana seed has germinated, how often should you water Marijuana seeds?
Once it germinates though, how often you should water marijuana seedlings varies according to the temperature of where the marijuana seeds are growing, but as a rule of thumb, you should water the marijuana plant once the soil is dry. An easy way to tell is if you try and lift the edge of the pot with one finger; if it feels “light” then it’s time to water, if not then leave it a few more days to evaporate and check back often to water. Usually, when you follow this technique, it helps with the formation of trichomes on your marijuana plants during the flowering phase which is equal to dank-er flowers.
You might also find our FAQ submission How Do I Feed A Plant? useful!
How to water and flush marijuana plants
Like all plants, cannabis requires water in order to perform its basic functions. Water helps plants absorb nutrients from the soil and then moves up the plant and into the leaves, and without it, the plant can’t survive. But giving a marijuana plant the proper amount of water may be more difficult than you think.
There isn’t an exact science for watering a weed plant. You can’t observe the roots in most cases to see if they need water. Also, a plant is constantly growing and the climate it’s in will fluctuate, so the amount of water it needs constantly changes.
Here are some tried-and-true tips to keep your weed plants healthy and properly hydrated.
How often should you water marijuana plants?
A common mistake first-time growers make is to overwater marijuana plants. A cycle of wet and dry is healthy and necessary for the roots of a plant to grow out and reach deeper into the soil.
Additionally, roots pull in oxygen as soil dries and when soil is too wet, the plant can’t pull in oxygen efficiently and essentially can’t breathe.
Below are general estimates and are meant to give growers a rough sense of frequency of waterings; if a plant needs water and it falls outside of these ranges, water it.
|Plant stage||Water every # of days|
How to tell if a cannabis plant needs watering
The best ways to tell if a weed plant needs water is to:
- Stick a finger 1-2 inches into the soil—if it’s wet, hold off; if it’s dry, it’s time to water.
- You can also pick up a pot and feel its weight to determine if it needs water. This will take some experience—be sure to lift up your pots after watering to get a feel for how heavy they are when full of water. This will also give you a sense of what a light, dry, plant feels like.
An under-watered marijuana plant looks droopy and weak, with yellow or brown leaves; there is no strength in the leaves and they look lifeless.
Leaves of an overwatered plant look slightly similar in that they droop, except the leaves will be dark green and the leaf tips will be curled.
Note how often you water plants and write it down in a log. Get your marijuana plants on a watering schedule—as they grow out of the seedling stage, watering every two to three days is ideal.
Keep in mind that as plants get bigger, they will need more water and need to be watered more frequently.
When growing weed outdoors, you’ll need to water more often as the weather gets hotter and less often as it cools.
When you find the sweet spot between too wet and too dry, your plants will flourish.
How much should you water marijuana plants?
The amount of water your marijuana plants need depends on a few factors:
- Size of plant
- Outside temperature
- Overall health
- Stage of growth
You want to water a plant enough to soak all the soil in the pot. Water should pool up on the surface of the soil when you’re watering, and come out the drainage holes in the bottom of the pot after a couple seconds. If water sits on the surface of the soil, that means it’s too wet and doesn’t need more water.
If a weed plant is very dry, water will run straight through the soil and pot and quickly come out the drainage holes. If this happens, water the plant a little bit and then come back to it after 15-20 minutes and water it again, and maybe even a third time. This allows the soil to slowly absorb water until all of it is thoroughly wet.
Roots are constantly on the hunt for water as they grow and stretch out. As a plant gets bigger, so should the watering radius—the area around the stalk of the plant that you water. Doing this will help guide roots to the edges of the pot as they seek available nutrients in soil.
Watering too far away from the roots can create standing water, which can lead to root rot, mold, and pest issues.
Is your container the right size?
To properly water a cannabis plant, it needs to be in the correct size container, or a big enough hole if it’s in the ground. If a pot is too big, the plant’s roots can’t drink water where they don’t reach. If the roots aren’t absorbing water, water will sit in soil and take a long time to evaporate, which can promote root rot and unwanted insects and fungus.
Conversely, if a container is too small, the roots won’t be able to stretch out, which can stunt the growth of a plant. Less soil also meant you’ll need to water the plant all the time, which will add labor.
Ideally, cannabis plants should start in a small pot and progress to bigger and bigger pots as they outgrow each container. For example, you can start a seedling or clone in a 4″ or 1-gallon pot, then move on to a 2-gallon, 5-gallon, 10-gallon, and so on.
Plants are ready to transplant when a healthy root structure encompasses most of the soil and the roots aren’t bound. When transplanting, take time to look at the quality of the roots: Bright white roots with a strong, thick structure is a sign plants are getting watered correctly.
What is flushing?
Flushing is an important part of the marijuana growing process, when you stop giving a marijuana plant nutrients and give it straight water. This is done to flush out nutrients that may have built up in a plant during its life.
Flushing is done for about a week before harvest, at the end of a plant’s flowering stage when buds are almost ready to cut down.
A flush can also be done to clear plants of nutrients if they have a nutrient imbalance, such as nutrient lockout, when your plants are overloaded with nutrients and unable to absorb new ones.
How to flush weed plants
Flushing marijuana plants before harvest
The final flush should occur for a week or so before you cut down weed plants for harvesting. Water your plants with the same amount as you normally would, but only with water. This will force the plant to use the nutrients stored within it—if its nutrient reserves are not used or broken down, it could affect the quality of your harvested buds.
By looking at the trichomes on marijuana plants, you’ll be able to tell when the plants are ready for a flush—begin when they start turning milky.
Different growing mediums require different flushing timeframes before harvest:
- Soil: 7-10 days
- Rockwool and coco: 7 days
- Hydroponics: 5-7 days
If growing in amended organic soil, it is not recommended to flush plants. This is because the soil already holds all the nutrients the plant needs to thrive, and by flooding the soil you can wash away and damage the complex ecosystem that you’ve worked hard to develop.
When to stop watering before harvest
Water your marijuana plants as normal when in the flushing phase—don’t let them get too dry or too wet. Make sure not to harvest dry or wilting weed plants—they should be nice and healthy when you cut them down.
A Guide To Water your Marijuana Plants
But, when it comes to marijuana plants, the whole watering process requires a little more finesse.
Not to worry though! In this article, we will cover all the ins and outs of watering weed so you can run a smooth-flowing operation.
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- The importance of H2O
- Types of water for watering weed plants
- What is the right temperature to water your plants?
- How often should you water your plants?
- How much water do marijuana plants need?
- The best method for watering weed
- Why the right ph value is key
- Watering weed in a nutshell
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.
Types of water for watering weed plants
We often don’t think about it, but water comes in different types and qualities. While some are perfect for watering pot plants, others might be ill-advised due to the water containing harmful substances or unwelcome minerals and bacteria.
pH and EC values are important factors when it comes to watering plants. Not only do these factors have a strong influence on your root development and the number of nutrients they can absorb, but they also play a vital part in the general health of your plants.
What you need to keep in mind is that these pivotal factors may strongly fluctuate, depending on the source you are getting your water comes from.
Let’s have a look at a few varieties and what makes them suitable (or not).
- Tap water
- Bottled water
- Distilled water
- Reverse osmosis water
- Spring, reservoir, or well water
- River water
By far the most frequently used source of water for watering weed. It’s cheap and widely accessible. But, there are a few things to take into consideration before you reach for your garden hose. Water has different degrees of hardness. We determine the hardness of water by the amount of calcium and magnesium in the water. These elements occur naturally in rocks such as lime and chalk and our groundwater. The more of these minerals in the water, the harder the water will be.
As such, tap water can be either soft (EC – 0.4), medium (EC + 0.4) or hard ( EC + 0.8). Also, tap water generally has a pH value of over 7.0 and often contains lime, chlorine, and fluoride in some cases, which can kill soil life and decrease its quality.
To make sure your tap water is in optimum condition for your plants, there are a few precautions you can take: let the water sit for about 24h so some minerals and other components can sink to the bottom of your watering can. You could also use an osmosis filter in order to filter your water.
Bottled Mineral Water
Bottled water is perfect for people to drink. But, aside from becoming a costly affair, it might not be the best option for watering your cannabis plants. While mineral water does not contain any harmful substances, and its EC levels are lower than 0.5, with a pH around 7, it still contains high amounts of some minerals such as calcium, which may end up affecting your soil life and how your plant grows.
Most supermarkets and convenience stores sell distilled water, but you can also quite easily create it at home, which makes it, even more, cost-efficient.
Distilled water doesn’t contain any minerals or any other type of microorganisms. This water is perfect for plants since you basically start with a blank slate. In order to use it on plants, the only thing you have to keep into consideration is that it usually has a pH value of over 7.0 and an EC (water hardness) of 0.0. We advise simply adjusting the pH value and adding some calcium and magnesium until it reaches 0.4 EC.
Reverse Osmosis Water
Reverse osmosis water is quite similar to distilled water, just not as pure, since it doesn’t remove all the minerals such as chlorine, lime, etc.) and impurities from the water.
Reverse Osmosis water arises by using a filter that traps the minerals and other unwanted particles.
You can make this type of water by simply using a decent osmosis filter and setting it up. Depending on the filter, osmosis filters tend to produce less than 0.4 EC and a pH value of about 7.0. This makes the water potable and safe to used to water your plants without needing to modify it further.
Rainwater sounds like the most logical option, as the water comes naturally from nature. Growers who use rainwater usually do this by using tanks that fill them with rainwater and then store it for later use.
Rainwater is one of the cleanest types of fresh water on the planet. It usually has a pH of 7.0 and an EC that does not exceed 0.4. This makes it suitable for watering almost any type of plant, as nature tends to automatically remove all harmful elements before the rain falls.
To get the highest quality rainwater, you need to set up a water collection system. Keep this as clean as possible to avoid the inclusion of elements that could reduce the quality of the water or contaminate it.
We advise you to also use an impurity filter and recommend using rainwater outside the cities. This because the rain that falls in the city contains traces of pollution because the air here often contains traces of smog or pollution.
Spring, well or reservoir water, etc.
I would honestly not recommend using water obtained from wells, springs, reservoirs, and other similar sources since you cannot be sure of its composition. A visit to the city waterboards might supply you with more information about its mineral and chemical content. This is highly important since there is a possibility that the water could be polluted with chemical insecticides or mineral fertilizer, which renders it useless for your plants. Also, these types of waters tend to contain large amounts of harmful fungi and bacteria.
In order to use this type of water, we recommend doing some serious research beforehand. If you should decide to go forward, make sure to treat the water accordingly and meticulously prepare your storage area to avoid fungi and bacteria from spreading. If you prefer to use water from your own well, you can drain it first and treat the surface using ultraviolet light or shock chlorination before use.
River water may sound like a great idea for watering weed, but I personally would advise against it. Aside from having to deal with a lot of similar issues of the previously mentioned well water, rivers are generally miles long and often polluted with pesticides or harmful substances by industrial areas or factories along the stream. Aside from that rivers can also contain dead animals that contaminate water during decomposition.
In order to use river water, you should probably live near somewhere where your town waterboard can assure you that the rivers don’t contain any sort of contamination which is, in all honesty, a long shot.
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.
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 😉