How To Water Cannabis Plants: A Comprehensive Guide
Your cannabis plants need water in order to thrive. Seems simple enough, doesn’t it? But did you know that incorrect watering is the most common reason for plant health issues? Learn how and when to water your plants so you can avoid any problems before they have a chance to happen!
Watering cannabis plants seems like the easiest thing to do, yet many growers, especially those new to cannabis cultivation, make mistakes with watering. Overwatering is one of the most common reasons for all sorts of growing troubles such as nutrient deficiencies and cannabis diseases, although giving your plants too little water can also negatively affect their growth.
HOW MUCH SHOULD YOU WATER CANNABIS?
One issue with watering plants is that it isn’t really an exact science, and many different factors contribute to how much you should administer. As an obvious example, as your plants get bigger, their watering needs will change. But there are other, more complex variables that also determine how much or little you should drench your plants. Let’s discuss some of the most vital:
STAGE OF GROWTH
Cannabis plants have different watering demands depending on their stage of maturity. The specific guidelines we share below apply to mature vegetating and flowering plants. Seedlings and clones require much less water.
In the early stages, avoid watering your plants with a powerful stream that might knock them over and disturb developing roots. Instead, use a light mister to gently moisten the substrate.
Wait for the soil to dry out completely before repeating the procedure. How quickly the soil will dry will depend on your environmental conditions, but this roughly translates to misting once every 2–3 days.
The type of growing medium you use largely determines how much water the soil can hold, and drainage plays a huge role in how often/how much you water your plants. Cannabis likes rich yet airy and “fluffy” types of soils that are well-draining. As another consideration, the growing containers themselves must have holes punctured in the bottom to allow the water to escape. More compact soil mixes will hold moisture much longer, so they require less frequent watering as a result. Otherwise, moisture can linger in the soil for some time, which can lead to nutrient deficiencies, root rot and fungus, pests, and a whole lot of other problems.
Here is a quick way to check if your water is draining properly: If it takes several minutes for water to drain after drenching the soil, and/or if it takes longer than 3–4 days for your soil to dry out, it’s likely that you have a drainage issue. Even if you don’t see adverse symptoms now, it could definitely lead to more problems down the line. In this case, you can add perlite or something similar to your soil to aerate the mix and improve its drainage ability. Perlite ensures that water doesn’t stay too long in your pot. The key to good soil for cannabis plants, whether store-bought or homemade, is to balance moisture retention with water drainage. This usually means soil that is dark and rich, but amended with perlite and/or other substances to promote a healthy and efficient medium for plants to grow.
SIZE OF CONTAINER
Then of course, the dimensions of your container will also affect the overall balance between moisture retention and drainage. If you have a tiny plant in a huge pot, drenching the whole substrate is going to drown the poor thing before it gets a chance to flourish. Similarly, you might experience the opposite issue with huge root-bound plants stuck in minuscule pots. This is also the reason that growers normally start seedlings in smaller pots, then up-pot them later as the plant grows. A small seedling pot makes it much easier not to overwater the sensitive seedling.
OUTSIDE TEMPS AND LIGHT INTENSITY
Cannabis plants don’t always grow at the same pace. A plant in a cooler environment, for example, will grow much slower than one under balmier conditions. Light intensity plays another big role here. Plants that receive more heat and light are bound to have higher water and nutrient requirements than those with meagre light and chilly temps.
HEALTH OF CANNABIS PLANTS
The general health and vitality of your plants will also determine how much water they require. If growth is slow or stunted, or if a plant is afflicted with diseases or pests, it will likely not need as much water as one that is thriving.
HOW TO TELL IF YOUR PLANTS ARE THIRSTY
You now know about the factors that determine how much and how often cannabis plants need water, and how these factors can be different for everyone. So now, how can you tell exactly when you should water?
Here are some signs that your cannabis plants are thirsty:
DROOPING, WEAK PLANTS
If your cannabis plants are very thirsty, they will droop. The whole plant will appear rather sickly and lifeless, so it’s difficult to overlook this sign. One catch here though is that thirsty plants can look very similar to those that are drooping because of overwatering. The difference here is that the leaves of overwatered plants are usually dark green and form a “claw” where they curl and bend downwards, so the whole plant takes on a heavy and waterlogged appearance.
If you’re somewhat experienced, you should be able to tell these conditions apart. Most of the time, it should be obvious if the drooping is from over or under-watering: If the soil is bone-dry and you know you haven’t watered in quite some time, the sickly appearance of your plants is less likely from overwatering.
Tip: Know that slightly underwatering your plants is always better than overwatering. If you water thirsty, otherwise healthy plants, they should normally recover their appearance in a couple of hours. Occasional underwatering doesn’t usually have harmful consequences. Overwatering, on the other hand, is a silent killer.
YELLOW OR BROWN LEAVES
Along with your thirsty plant wilting and drooping due to a lack of water, it may also display discoloured leaves in shades of yellow and brown. While it is perfectly normal for plants to develop yellow leaves during the final weeks of bloom, a healthy vegetating plant shouldn’t have any/many dry, yellow, or brown foliage.
JUST CHECK THE SOIL!
Take the guesswork out of your watering routine with a simple method. Placing the tip of your finger into the top 5cm of soil provides a good indicator of how dry the upper soil has become. However, it won’t allow you to detect the water content of the middle and bottom of the growing medium.
Weighing your pots instead will give you a clear picture of how much water remains. You can operate based on a general feeling of how your containers feel in your hands when they are dry compared to when they are saturated. Even better, weigh them to know exactly when they’re ready for some more H₂O.
HOW TO WATER YOUR CANNABIS PLANTS
Here is a simple rule: Water less, but water well! Rather than giving your plants a little bit of water often, treat them to a healthy, less frequent soak. But how much water is sufficient?
A good soak means watering the medium to 25–33% of the pot capacity. This amount of water will provide the root system with all it needs, without causing pooling and potential fungal issues.
When watering, aim for the middle of the substrate first. After letting the roots breathe, water the edges of the container too. This approach will encourage the root ball to reach to the edges of the pot, and also shuttle nutrients sitting in the top of the medium down to the root system below.
This method will deliver the correct amount of water, without creating pools in the substrate. Excess water creates a humid environment—a perfect breeding ground for fungal pathogens that lead to root rot.
DON’T LEAVE YOUR PLANTS SITTING IN RUNOFF
Along with your containers featuring holes at the bottom for water to escape from, the containers themselves should be lifted slightly off the ground so that all the water can drain and plants aren’t sitting in stale liquid. Drainage trays can catch this runoff, but should immediately be dumped after collection to avoid creating a breeding ground for bacteria, pests, and mould.
THE IMPORTANCE OF PH WHEN WATERING PLANTS
If you are growing cannabis organically in soil, you shouldn’t need to worry much about the pH level of your water/nutrient solution. But for the majority of cannabis growers who are using common mineral nutrients and grow weed in soil, coco, or hydroponically, the correct pH level of the water is very important.
The reason for this is that cannabis plants have a limited pH window where they are able to take in nutrients. If the pH level of the water is either too high or too low, the plants are unable to take in nutrients even if they are present, a phenomenon known as nutrient lockout.
When you grow in soil, the pH range of your water should be 6.3–6.8. If you grow soilless (e.g. coco) or hydroponically, the pH level needs to be even lower, 5.5–6.1. To test your water pH, use a pH measuring stick or pH measuring drops. If the pH is too high or too low, use some drops of “pH down” or “pH up” to adjust your water to the right level. Most of the time, if you’re using tap water, your pH will likely be too high.
Also, if you’re adding cannabis nutrients to your water, measure the pH after each feed. This will give you accurate data of how you have influenced the soil. It will also let you know if you need to add more nutes, or modify the dose during next feed.
BOTTOM LINE—WATER WELL, BUT NOT TOO OFTEN!
If you know how and when to water your plants, and are aware of any associated issues along the way, you can prevent most common cannabis growing problems. You will raise happy, healthy plants, and can look forward to fantastic yields!
The HI-98107 pHep pH tester provides fast and accurate pH readings. The easy-to-use device is designed for non-technical users, and can help both novice and advanced growers measure water pH.
HI-98107 pHep pH tester provides fast and accurate pH readings. The easy-to-use device is designed for non-technical users, and can help both novice and advanced growers measure water pH.
Click here to find out everything you need to know about how and when to water cannabis plants. Watering may seem easy, but many growers still get it wrong.
5 Ways to Grow Cannabis in Hydroponics
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In this article we’re going to talk about 5 ways to grow cannabis in hydroponics. Many people think that growing in hydroponics is the same every time, but hydroponics simply means working with water – there are many different ways to grow plants using this system.
People often speak wonders of growing in hydroponics, and while it’s true that you can get a much bigger yield through hydroponics, it requires much more care and tending to compared to growing in soil. In this article we’re going to show you different kinds of hydroponic grows; if you’re interested in growing hydroponically then this is the article for you. Read on to find out about this system and what you should and shouldn’t do.
First of all, you probably already know that plants need water, light, nutrients, carbon dioxide and oxygen. Cannabis plants are capable of absorbing everything available to their roots so if you’re giving them water constantly, you’ll need to keep control of the pH levels so they can absorb all of the nutrients and grow as much and as healthy as possible. You’ll need to keep an eye on them every day because if the pump malfunctions, your plants will die off, or if they have too high of an EC then you could have serious issues – pH and EC meters are extremely important.
You’ll need to keep some replacement pumps handy, both for the air and water flow, because your plants depend on these devices to stay alive when planted in this medium and if the pumps break down and you take too long to realize it, you’ll end up with some dead plants within hours.
Water temperature is extremely important – if it’s too warm it won’t have enough oxygen and the roots will rot, and if it’s too cold the roots won’t absorb anything at all. The water will need to be between 20 and 22ºC.
Here’s a list of some of the different hydroponic techniques:
This is the most used hydroponics system around, and many growers assume that this is the only kind of system around. The setup is simple; 12l flowerpots full of expanded clay balls where you’ll be planting your cannabis plants. The pots are connected through a drain on the bottom and they’re all connected through a pipe and drainage system.
A tank and water pump feed water to your plants alongside your chosen nutrients solution a few times a day; this is set up using a timer. A little hose at the bottom of each stem will water your plants as needed.
This is an effective system but you need to make sure that the pump doesn’t malfunction and have a replacement one or your plants could be in serious trouble. Everything else is extremely simple to use, and this system is the perfect one to start with if you’re new to growing hydroponically.
One of the few negative aspects of this method is that you need to pay special attention to your plants’ roots to make sure that they don’t clog up the hole where the drain is, or you might end up with some flooding in your grow.
DWC – Deep Water Culture
This is a hydroponics system in which the roots are suspended in air. Plants are grown in a container over a separate tank. The container is full of clay balls to keep the plant in place and act as a substrate, and the water goes in the lower tank along with the nutrients.
The bottom of the container is a sort of mesh so that the roots can grow through it without any of the clay balls falling through. Roots seek out the water in the tank and that’s where they feed from, although at the start they simply absorb humidity until the roots reach the water, which is when your plants will really begin to grow.
An air pump with its corresponding airstone will ensure that the water is oxygenated enough and so that it doesn’t stagnate, letting your plant live with the same water for more or less a week.
You need to mix water and nutrients up for your plant during the entire grow and your plants root systems will begin growing spectacularly. Your plants will steadily absorb more nutrients, accelerating an extremely productive process. You need to keep a close eye on your roots and air pump though, as the water runs the risk of becoming stagnant and rotting the plants’ roots.
Ebb & Flow
This system is similar to the DWC system, except that instead of allowing the roots to reach the water and sit there, the roots are flooded with water for a few seconds and then emptied again various times throughout the day. You use a sort of watering table with mesh pots that have expanded clay in them.
Underneath the table you should have a tank and a water pump – every now and then the pump should pump water up into the table to flood it, wet the roots with nutrient-rich water for a few seconds and then go back into the tank.
Your plants will be permanently hydrated and well-fed when growing in this system, and if you adjust the pH and EC adequately you’ll accelerate many processes in the plants making for more quantity and quality.
You’re going to need to keep control of how often you flood the table and for how long, or you could end up with some serious rot problems. This may seem like one of the simplest methods, but it’s reserved for the most professional of growers.
NFT – Nutrient Film Technique
This is similar to the DWC system again, although it’s used for clones rather than large plants. The DWC method can be a bit big for clones, as they don’t grow many branches nor do they have the same yield as a seed.
If you work with the NFT system then clones are your best option. This system is done on an inclined surface in which water is pumped to the top end and it filters back into the water tank at the bottom.
On the surface above the water flow is where the plants go, with the roots dipping down into the water flow. The roots reach the water which is full of nutrients, meaning that they’ll have a perfect, balanced diet. This makes for high yields in a small amount of time.
This is one of the easiest systems to clean and reuse, however you’ll need to control the water levels, as once the roots grow a bit they can block the water flow and end up flooding and rotting the roots.
Aeroponics is a variation on hydroponics that involves placing your plants in trays with holes that have neoprene discs in them. In each disc you need to place one clone, with the roots on the underside of the disc.
The tray is suspended in the air over a water tank that has a sprinkler system in a PVC tube circuit with holes in it and Sprayers, which are the devices that will keep the roots humid through a constant flow of water.
Your plants will have a never ending source of water and nutrients and this is the best possible technique for rooting clones. You take up the same space with one plant in an RSS system as you do with five clones in an aeroponic system, and you’ll get the same yield from those five clones as you would from the seed. Keep an eye on the sprayers so that they don’t get blocked and end up leaving your clones without any water or nutrients.
These are some of the most used hydroponic methods when it comes to grow cannabis. Hopefully this article has been of help, if you have any questions, doubts or suggestions go ahead and leave a comment down below; our team of experts will get back to you as soon as possible.
Author: Javier Chinesta
Translation: Ciara Murphy
5 Ways to Grow Cannabis in Hydroponics – Learn about the different ways to grow hydroponically and get amazing yields with little effort.