If this is your first time growing a cannabis plant, then these 5 tips for watering your precious crop are SURE to help. Especially tip #3 Learn the art of watering weed plants, how to avoid watering problems, how watering weed properly produces strong, healthy cannabis plants. How much water your plants need, how often you should water, and what influences a cannabis plant´s water absorption rate.
Top Five Tips for Watering Your Marijuana Plants
As marijuana is a plant, it needs water, nutrients, sunlight, and air to grow. Although it is traditional to use soil as a planting medium, there is a myriad of alternatives on the market. However, no matter the medium, proper hydration is the be-all and end-all of successful marijuana plant growth. It is especially the case since it consists of 80% water!
Too many new growers make the mistake of believing that watering their plants is an easy process. The main crime against weed plants is overwatering. For some reason, newbies also tend to think it is essential to saturate their crops. If you add too much water, you run the risk of obstructing your crop’s oxygen intake. But if you under-water your plants, they get thirsty, and their leaves start to wilt.
An overwatered marijuana plant often has drooping leaves. Unlike wilted plants, the leaves of overwatered plants are so saturated with water that they curl in on themselves. Remember, your weed uses its root systems to breathe air. When you flood these roots, you’re in danger of drowning the unfortunate plants. Another sign of overwatering is yellowing leaves.
Spotting an under-watered plant is easy. Such marijuana plants look weak, lifeless, and will display clear signs of wilting. In extreme cases, the leaves are brittle and feel like paper when touched. If you have a cannabis garden for the first time, keep reading to learn more about optimal watering strategies.
EDITOR’S CHOICE – Homegrown CannabisCo
Homegrown CannabisCo are the masters when it comes to seeds. Offering a massive variety of cannabis seeds that are well categorized, not only does this company create a resource for superb quality options including feminized seeds, it also provides extensive growing information for those looking for some support along their journey.
Best Products for Hydrating Cannabis Gardens
Below, we provide you with a list of useful products that will help you water the plants correctly. They are designed to take the guesswork out of proceedings and reduce the risk of underwatering or overwatering your precious plants. No matter what option you choose, bear in mind that there are different growth cycles. Each of them requires a unique watering schedule.
Here is a quick overview:
- Seedling Stage: It is best to water twice a day, to begin with, but focus on frequency over volume.
- Vegetative Stage: Daily watering works best if you’re using small pots. If you have large containers, switch to watering every two days.
- Flowering Stage: Water every 2-3 days.
As for pot size, you have to choose your container carefully if you wish to hydrate your marijuana plants properly. Common sense tells us that the plant can’t consume all of the water if its roots can’t reach! If you have a container where the roots don’t reach, you have leftover water. This moisture then becomes a target for root rot, insects, and fungi.
As a rule of thumb, start things off with pots or cubes that are one square inch apiece. As your plants grow, increase the size of the container to four square inches. Eventually, you will need a one-gallon pot, followed by a two-gallon container, and so on. Upgrade the pot each time your plant outgrows it.
Tip #1 – Use Smart Pots
These particular pots are made with canvas to help your marijuana plants’ roots breathe. They also enable water to drain and ensure heat escapes. Smart Pots are a prevalent option amongst indoor growers. Some users point out that they tend to dry out faster than with standard containers because the air passes through them. Once you get used to this adjustment, you’ll thoroughly enjoy using Smart Pots.
Tip #2 – Employ a Drip Line System
If you have a large crop or are gardening in a hot climate, a drip line system could be a lifesaver. It enables you to water your plants and distribute the liquid consistently evenly across the container. Let’s say you use Perlite and overwater your pot. You will find that the volcanic glass rises to the surface where it loses its effectiveness.
As a bonus, controlling the frequency of watering and the volume of water you add helps you manage nutrient supply. A proper drip system will include a series of small tubes and droppers. These connect your water supply to each plant in your garden.
Tip #3 – Add Perlite
Although this heat-treated volcanic glass is an exotic material, it is becoming increasingly popular in marijuana growing circles. It is typically added to growing mediums because it improves the structure of organic soils. As it is a neutral substance, it doesn’t impact the pH of your water or nutrient EC.
When you heat this natural substance over 1,400 degrees Fahrenheit, it expands enormously to become Perlite, a commercial material. You will notice how white it looks, and you can purchase it in fine, medium, and coarse grades. If you use a lot of nutrients in your plants, add up to 50% perlite. Reduce to 20% if you don’t plan to add a massive amount of additives and nutrients.
Tip #4 – Invest in a Timer
If you use a drip line system, you automatically use a timer. It reduces the amount of work you need to put in because the system waters the plants on a schedule. It also controls how much water you use. Once you have a system with a timer, it ensures your marijuana plants are well taken care of. You can even leave the state and allow your timer to do its thing.
Tip #5 – Look at Other Auto-watering Cannabis Systems
We have already mentioned the drip line system, which is a form of auto-watering cannabis plants. It is difficult to emphasize how much time and stress one of these systems will save you. It is only when you attempt to water manually that you genuinely understand.
Aside from the drip irrigation option, you can also choose sprinkler irrigation. Once again, it is activated when scheduled. Instead of providing water to each pot individually, a sprinkler system disperses water across all plants.
It would be remiss to suggest that auto-watering cannabis systems are foolproof or free from disadvantages. They aren’t especially easy to set up, and such a system could prove excessively expensive for small home growers. If you use a drip system in particular, you have to check and clean the pipes regularly to stop clogging. Otherwise, you risk allowing mineral and algae build-up, which may result in hampered water flow.
Also, if your system dispenses the water beneath the soil, you won’t know if it is feeding your plants properly. If there is a problem, you won’t notice for several days until your plants start showing signs of distress. Finally, you can’t merely set up your system and leave your crop alone for days on end. Regular checks for signs of disease or ill-health are essential.
How Often Should You Water Cannabis Plants to Benefit from Good Buds?
We offered some very generic outlines of how often you should water your seedlings, along with plants in their vegetative and flowering stages. However, there is no ‘hard and fast’ rule. Everything depends on the climate, type of strain, the growing medium you use, and whether you’re growing indoors or outdoors.
Overall, it is a ‘safe bet’ to water your plants a little. Ideally, you’ll reach the point where you soak the pot with a little bit of runoff. While the water should remain on the surface briefly, it needs to drain into the growing medium relatively quickly. Next, you have to monitor your plants carefully and look for signs of underwatering or overwatering.
As for when to water your plant next, experts agree. They say that when you use soil, you should water the plants once the first couple of inches of soil feels dry. Another telltale sign is if the container feels exceptionally light. Are you adding nutrients to the water regularly? If so, add enough water to get up to 20% runoff that drains out of the container’s bottom. This process prevents a build-up in your soil.
When you know about checking the soil regularly, you should get a feel for how often you need to water. You also learn more about the volume of water required. Water the marijuana plants at the first sign of the leaves wilting.
A lot of new growers tend to rely on their trusty watering can. It isn’t a bad option when you only have a handful of cannabis plants to worry about. However, once you have a substantial garden, your can is too small to fulfill the demand for water. You can persist, but it will involve multiple refills.
An increasing number of cultivators are investing in devices such as Battery-Operated Liquid Transfer Pumps. These pumps enable you to pump water from a large container to your weed. The most popular options are capable of reaching the bottom of a 3-gallon jug.
When watering weed, there are some other considerations.
Even if you get the watering process correct, a low-quality water source could undo all of your hard work. The pH scale runs from 0 – 14 and determines how acidic or alkaline a substance is. 7.0 is considered neutral, and clean water’s pH is in and around that mark. The pH of water dictates your plant’s capacity to absorb nutrients. For the record, 0 – 6.9 is acidic, while everything from 7.1+ is alkaline.
Through trial and error, growers have determined that marijuana plants grow best at a pH of around 6.5. You can measure pH by adding a pH meter to a sample of water runoff. This is ideal because runoff water has passed through your grow medium and drains from the container. If the pH is too high or low, you need to purchase a particular product. The goal is to ensure it is as close to 6.5 as possible.
Parts Per Million (PPM)
PPM measures the number of minerals dissolved into your water source. For instance, a reading of 115ppm means there is 115 milligrams per liter of minerals present in your source. During the vegetative stage, the ideal PPM is 500 while it rises to 1,000 during the flowering stage. Invest in a TDS meter. It measures the water source’s PPM and ensures your plants are not receiving too few or too many nutrients.
Unfortunately, you may live in an area where the water quality is compromised (Flint, Michigan anyone?) If this is the case, the water you use on your plants may have bacteria and other pollutants. These unwanted additions could contaminate the water. Trying to grow plants in these circumstances will only lead to disaster.
To prevent a catastrophe and the waste of countless hours, money, and energy, invest in a reverse osmosis (RO) filter. These filters remove up to 99% of dissolved salts within the water. As a result, your marijuana plants get the cleanest possible end product.
Conclusion: Watering Cannabis Plants
If you have never grown marijuana plants before, you will be shocked at how much effort goes into the process. It isn’t just a case of planting them, adding nutrients, and watering as and when you feel like it. There is a range of details to consider if you want a strong and healthy crop.
Watering your marijuana plants is the most crucial consideration. However, it isn’t as easy as getting a watering can and using it like you would with a bunch of roses. When choosing a watering schedule, you have to adjust depending on whether you grow indoors or outdoors. Climate considerations are also of paramount importance since heat and humidity have a significant impact on cannabis plants.
Finally, you have to consider your growing medium. If you have a small garden, manual watering with a traditional watering can is fine. If you have a more extensive operation, it is worth investing in an auto-watering cannabis system. It will help take the stress out of matters. When all else fails, the weight of your pots can serve as a useful watering guide.
If they are cumbersome, it means the soil is too wet, and you should wait for a few days. If they are too light, it is time to water immediately. It is especially the case if the plant’s leaves are showing signs of wilting.
EDITOR’S CHOICE – Homegrown CannabisCo
Homegrown CannabisCo are the masters when it comes to seeds. Offering a massive variety of cannabis seeds that are well categorized, not only does this company create a resource for superb quality options including feminized seeds, it also provides extensive growing information for those looking for some support along their journey.
Watering Weed: A Beginner’s Guide with Kyle Kushman
Learn the art of watering weed plants and you’ll avoid many of the problems that can ruin a good crop. This is especially important for beginners!
The trick is knowing when to water, how much to give, how to avoid drowning your plants or drying them out. It’s not as simple as constant feeding. Over watering weed plants can be just as destructive as letting them dry.
This article will cover all the basics of watering weed, from pot sizes to cycling wet-to-dry, to flushing your plants at the end of flowering. We’ll give you weed watering tips from experts like Kyle Kushman, and we’ll show you how important watering is to growing strong, healthy cannabis plants.
How do you know when to water cannabis plants?
Any watering schedule for weed will depend on the medium, the climate, the strain, and your setup. Some soils drain quicker than others, some lamps are hotter, some plants are thirstier. Every grow is different.
The best way of watering weed plants is to cycle wet to (almost) dry. As the moisture recedes, the roots expand, searching for water. This makes for a healthy, solid root ball and a stronger, sturdier plant.
When the soil is dry to a depth of a few inches (don’t be shy, stick your finger in) it’s time to water again. This is usually around 2 – 3 days after watering, but every grow is unique so DO NOT take this as a hard and fast rule.
Once you have a few indoor grows under your belt, you’ll be able to judge when to water your weed plants by picking up and weighing the container.
We’re often asked about weed and feed watering, but there’s no one-size-fits-all answer. Your nutrients will have a particular feeding schedule to follow, unique to the brand or product. Follow it as best you can.
Are you looking for nutrients? Your Homegrown seeds should be grown with Homegrown nutrients. Our breeders use them, so should you.
Tip: Keep a record when feeding and watering, watch how your plants react, make a note of positive and negative reactions and use this information to make improvements.
Watering weed: how much water do marijuana plants need?
One major aspect of watering weed is knowing exactly how much water to give your plants. Indoors, this mainly depends on the size of the pot and the substrate (type of soil). Watering outdoor weed plants depends more on natural drainage, weather and climate.
Tip: If you’re using water-based nutes, make sure you water enough to get 10 – 20% extra run-off from the bottom of the pots.
Pot size is hugely important when watering weed plants. It can affect the balance between moisture drainage and retention, determining whether your crops go thirsty or drown.
As your plants grow, you’ll move your seedlings from smaller to larger pots. If you can’t progressively transplant like this, you’ll need to take steps to mitigate potential issues.
- Water more frequently in pots that are too small (they’ll dry more quickly).
- For pots that are too large, try to focus the waterings around the central stem, keeping a dry boundary at the outer edges.
For plants in perfect-sized pots, you should saturate fully. Check our article about “autoflower pot size” to know the best fit for autoflowers and water properly.
Many indoor weed gardeners use soil-based media, which makes watering weed an essential skill to master, but not all soil is the same.
Those growing weed in coco coir, for example, may need to use more water than those growing in living soil. Coco is firmer and it can be more difficult for the water to get to the roots.
Indoor growing has advantages over outdoor. You get complete control over the conditions, which makes it easy to provide the ideal light, humidity, and temperature for growing weed.
Why does temperature matter? Warmer conditions will see plants lose moisture more quickly, increasing the frequency of waterings. What you can control indoor, you have to monitor outdoor.
Again, keep records, keep an eye on the weather and be ready to react. Use common sense – it’s unlikely your plants will need watering after a heavy rainfall!
Stage of growth
Watering weed plants that are 2 days old is different to watering huge, fully-flowering weed plants. Fortunately, we have experts on hand to break it all down for you.
Don’t have time to listen? Here’s the basics…
- A light misting several times a day for seedlings.
- A gallon every three to five days for young, vegging plants.
- Two gallons every three to five days for crops in late vegetative growth.
- Slowly reduce the amounts when the flowering stage begins.
Tips on how to water weed plants
- Quality over frequency. Watering weed is best when employing a wet-dry cycle — treat your plants to healthy, less frequent drenching.
- Hit the middle first. Give the root system enough time to drink before hitting the edges.
- Remove the run-off.That murky liquid in the runoff tray is an ideal breeding location for mold and rot.
How to flush weed plants
Flushing cannabis means purging your soil of nutrients, allowing the plants to use up the nutes they’ve already absorbed. This makes for better flavors and aromas in your harvested buds, but can also reverse the effects of over-feeding.
There are two primary reasons for flushing:
1. Nutrient imbalance
An overabundance of nutrients and improper pH levels can stress your marijuana plants. By flushing, you remove the excess buildup and restore the pH balance, promoting healthy growth.
How? You need to repeatedly water the pots with pH-neutral water. Repeat until your pH and PPM levels return to acceptable levels, then resume your normal schedule.
2. Ahead of harvest
Most growers like to perform a final flush before harvest, to improve the quality of the buds, but flushing timeframes differ depending on your growing medium. As a rule, you should flush…
- A week to ten days before harvest for soil.
- A week before harvest for coco coir and rockwool.
- Five days to a week before harvest for hydro.
Tip: Use three times the capacity of your container of pH-adjusted water for soil flushing. In soilless media, all you need to do is change your reservoirs.
Best water for your plants
Watering weed with the correct type of water makes a huge difference to your crop. As well as pH, the amount of dissolved solids in water (measured in parts per million, or ppm) can cause issues you’d much rather avoid.
Tip: Always check the ppm levels of your water, with a particular focus on biological and chemical contaminants.
Unfiltered tap water
Despite some growers’ claims, tap water can be used to grow cannabis, as long as you live in a municipality with good water treatment protocols.
- Affordability. Tap water is CHEAP!
- Ease of access. Taps are handily placed around the home and garden.
- Low-effort. Using tap water is as easy as letting it run and filling your bucket.
- Potential pH imbalance. If the pH is off, tap water can harm your cannabis plants and lead to nutrient lockout.
- Potential ppm issues. Large cities tend to have ‘hard water’ that could cause nutrient toxicity. Always check!
This source is pure, accessible, and guaranteed to be uncontaminated. It’s a great (if costly) solution for small gardens and growers worried about the pH of their tap water.
- Safe. Manufacturers have to abide by sets of standards for their products, which guarantees quality water for your plants.
- Easy. This one is second only to tap water in terms of accessibility.
- Environmentally harmful. Bottled water comes in plastic containers. One growing season ends up producing a lot of waste.
- Cost. The cost of bottled water is far higher than tap.
- PPM. Some bottled waters contain very high mineral levels.
Water collection systems
Eco-friendly cultivators love rainwater and gray water collection systems for watering weed. They work especially well in areas where water-saving is encouraged.
- Environment. There’s no better way to do your part in helping the planet than using rain water.
- Cost. Once you set up the system, watering weed will cost you nothing.
- Low-maintenance. The sustainability aspect also makes these systems easy, letting you reuse water hassle-free.
- Starting capital. Rain barrels and faucets aren’t extortionate, but some purchases are unavoidable and costly.
- Gray water needs filtering. Especially if your toiletries are full of chemicals.
Reverse osmosis systems
RO systems can deliver an almost unlimited clean water supply for watering weed, and they’re loved by expert growers like Kyle Kushman.
- Purity guaranteed. Think bottled water, but on a large scale and much more affordable.
- Suitable for large gardens. You’re limited only by how much you can take from the tap.
- Initial investment. Even the most basic systems can be costly.
- Not eco-friendly. ROs can lead to unnecessary waste.
Common watering issues: signs and solutions
Watering issues are easy to solve with a bit of know-how.
Over watering weed plants
Eager newbies have been known to spend every last minute watering weed, desperate to keep their plants from drying out. Overwatering weed plants is avoidable! Look out for…
- Drooping, wilting leaves.
- Top foliage yellowing.
- Brown leaf edges.
- Cupping and curling.
Always let the soil (almost) dry before you water again!
Under watering cannabis plants
Underwatering weed is just as avoidable, look out for…
- Papery thin leaves.
- Overall yellowing.
- Limpness and lifelessness.
Regularly check the soil and keep an eye out for adverse effects. Do not let your plants dry out!
The pH levels in organic soil are usually well-balanced and optimized for growth. If you’re using mineral-based nute solutions, or if you’re growing in coco or hydro, you’ll need to be extra vigilant.
- 6.3 – 6.8 for soil.
- 5.5 – 6.1 for coco and hydro.
Signs of bad drainage include:
- Pools on top of the soil.
- Pot stays wet and heavy for far too long.
- Bad smell, signs of over watering.
How can you resolve drainage issues?
- Make sure the drainage holes are clear.
- Add perlite to aerate the soil.
- Water more frequently, using less water per watering.
How to water cannabis plants if you are away?
Watering weed is a commitment that can’t be avoided, even if you’re on the holiday of a lifetime. The best auto watering system for weed can include homemade rigs as well as shop-bought systems. Our favorite solutions include:
- Makeshift bottle drips. Drill holes in a bottle cap and place it in your container, cap-side down.
- Plastic bag greenhouses. Get a large, clear plastic bag and a support structure (plastic polls or bamboo will do). Place it over a soaked pot to form condensation.
- Irrigation systems. Timer-controlled, on-demand systems are a cultivator’s best friend and a fantastic option for those cultivating away from home.
- Smart drip setups. These are a more advanced version of the bottle trick. They have smart timers to make sure your weed is watered and happy at all times
Mastering the basics
This guide for watering weed should have given you the tools and knowledge to know when and how to water your own plants, according to your set up. We mostly focused on soil-based cultivation, but you can visit the Homegrown Forum to find specific advice for hydro and other advanced setups.
Uploading your journal to Homegrown Diaries should deliver some practical assistance, too.
The basics are simple: cycle wet to dry, keep records, observe your plants.
Let us know how it goes.
About the author: Kyle Kushman
13 times Cannabis Cups winner. Kyle Kushman is a master breeder and indoor growing expert, a leading voice in the fight for legalisation and education, especially when it comes to growing cannabis at home. He’s been teaching and spreading the word for over 30 years, maintaining a consistently high level of achievement throughout his entire career.
How Often Should I Water My Cannabis Plants?
Knowing the right time to feed your plants can depend on many variables, so find out more below about what to consider in order to maintain the perfect watering ratio.
- 1. Factors that influence cannabis watering
- 1. a. Medium
- 1. b. Pot size
- 1. c. Pot type
- 1. d. Environmental conditions
- 2. The best way to water cannabis plants
- 2. a. Soil and coco
- 2. b. Hydroponics
- 3. Plain water or nutrient solution?
- 3. a. Feeding plain water only
- 3. b. Nutrient solution
- 4. Oversaturating the cannabis grow medium
- 4. a. Overwatering
- 4. b. Overfeeding
- 5. Top tips for marijuana watering
- 6. Best recommended heavy feeders
- 7. Cannabis crop watering faq
- 8. In conclusion
If you are new to growing Cannabis indoors or outdoors, having a thorough understanding of how frequently you should be watering or how often your plants require it can be quite difficult. There are many factors that play a huge role such as the pot size, strain, conditions, and substrate. In general, you should water when the medium is around 60-70% dry.
Below we’ll explain what you should know when it comes to watering your Cannabis plants.
1. Factors That Influence Cannabis Watering
First of all, every grower needs to understand that a question like “how often should I water?” is basically pointless because your watering schedule will depend on your own specific growing environment. There is no set way to water Cannabis plants or the best time to feed cannabis plants , or any type of house plant for that matter, however, each grower has their own set way, based on what is most practical for them.
There are multiple elements that can dictate how much water or how often you need to water your cannabis such as genetics, the phase your plant is in, growing setup and if you’re feeding with every watering or not, but the main ones are pot size, medium, and the environmental conditions.
As you may know, the substrate is where the roots will be growing, and depending on your preferred mix, it can hold more or less water which can affect the amount of water you need to water with and how long it takes for the water to evaporate. For example, if your substrate contains more perlite, it will allow more oxygenation which can increase the evaporation rate, or if it contains a lot of coco fiber it can take longer for the water to evaporate due to coco being able to retain water for longer.
Another factor that can affect how often you water your cannabis plants is the pot size because if there’s more substrate you will have to water with more water and it will take longer for the water to evaporate, obviously, this depends on the stage your plant is in. If your plant is still a seedling you don’t want to water it with a lot of water even if it’s in a 60L pot, but as it grows, you will have to water more and it will take longer for the water to evaporate (when compared to a 10L pot) depending on the conditions.
The type of pot you use, and the conditions inside the pot will have an effect on how often you will need to water your cannabis plants. There is a huge range of options available, but they are definitely not all equal. No matter what type of pot you end up using, drainage should be high on your list of concerns. Many novice cultivators fall into thinking that over drainage is a bad thing, as the plants won’t have a chance to feed properly from the water before it all drains away. This could not be further from the truth. To have the healthiest and most vigorous growth possible, you want your pots to offer high levels of drainage.
If you are using everyday plastic pots you will probably want to drill a few extra drainage holes before you start planting. It’s also a good idea to add a layer of pebbles at the bottom of the pot to help with overall drainage down the line. This stops the drainage holes from becoming clogged and ineffective. Here at FatsBuds, we recommend using air pots or smart pots, especially if you are going to be growing your weed indoors. These pots are made from canvas or fabric and allow for air exchange directly through the material which offers far better root zone oxygenation than terracotta or plastic pots.
This promotes the healthiest and widest-reaching root growth possible and allows for easier root zone temp control. These types of pots do tend to dry out a little quicker than traditional options, so keep that in mind when watering and make the necessary adjustments.
But the main factor that influences how often to water is the growing conditions. This happens because, if the humidity levels are too high it will take longer for the water to evaporate whereas if the humidity is too low, water will evaporate faster.
Also, if the humidity is too high it will encourage the transpiration process, making plants absorb more water and evaporating it faster while a lower temperature slows down transpiration and will take longer for the water to evaporate.
2. The Best Way To Water Cannabis Plants
As said above, there’s no better way to water plants, this will depend on your setup. There are several ways to water plants, either by hand-watering, having a drip irrigation system, and bottom feeding among others.
Soil and coco
Soil and coco (with any other things mixed in such as perlite and etc.) are the most common mediums and allows you to water any way you prefer.
This is the most basic way to water a weed plant. Normally you will add enough water until you see runoff. By watering weed in this instance, the growing medium will always stay well saturated, yet will never be encouraged to dry out and increase air capacity.
A very simple and foolproof way to water your cannabis plants by allowing the roots to suck the water up. This only happens correctly when the growing medium is dry enough, to cause a wicking action that will draw the water upwards to the roots.
Many growers swear feeding in this manner is the most advantageous, then again many will debate that the buildup of salts is far greater. It can also lead to mold and root rot issues if the system is not maintained to a high standard, so always be careful to drain the remaining feed water between feeds.
Drip irrigation system
A drip irrigation system is not very common amongst soil growers but it can be a great choice for coco or hydro growers. This method consists of a small hose on top of the pot that waters your cannabis plants by releasing drops of water non-stop. So to help you have an idea of how much to water and how often, here’s a small guide to help you water your cannabis properly.
Cannabis watering schedule for beginners
|Coco or Soil||≈100-200ml||≈300-600ml||≈700-1500ml||Usual amount of water + 10-20%||Every 2-4 days|
Just have in mind that this guideline was designed for plants grown in 10-12L pots and under optimal conditions, which are:
- Seedling stage – 65-70% humidity and 20-25°C
- Vegetative stage – 70-40% humidity and 20-26°C
- Early Flowering – 40-50% humidity (lowering approx. 5% each week) and 22-28°C
- Late Flowering – 30-40% humidity and 18-24°C
Your plant’s metabolism is affected by the conditions and will determine how much water your plant absorbs.
Just have in mind that even if your growing the same strain, it all comes down to your plant’s metabolism wich is affected by the conditions, so for example, if you’re growing our Wedding Cheesecake Auto under 30°C in 45% humidity, your plant will need much more water than the same strain under 25°C in 60% humidity.
Now, when growing hydroponically you need to have a drip irrigation system or any other system that waters your plants automatically. Watering using timed irrigation not only saves physical labor but also ensures the cannabis plants are fed the exact same amount, on a consistent basis. Organic growing mediums fed with drip stakes will grow much faster than when hand watering, and is replicated on enormous scales in the agricultural sector.
Cannabis watering guide for aero and hydroponic setups
|Hydro (Perlite, clay pellets, or rockwool)||100-400ppm||500-1200ppm||100-1600ppm||As close to 0ppm as possible||15min ON, 15min OFF (24/7)|
|Aeroponics||100-400ppm||500-1200ppm||100-1600ppm||As close to 0ppm as possible||5s on 4-5min off (24/7)|
So, to help you avoid overfeeding and give you an idea of how much you should feed your cannabis, here’s a table for hydro and aeroponics. Have in mind that the amount needed for soil or coco will differ depending on the brand you’re using so you should follow what they recommend.
When growing in hydro or aeroponics, it’s better to feed your cannabis by measuring the parts per million (which is basically the amount of nutrients in the water in a 1/1000000 concentration) in your nutrient solution.
Measuring ppm instead of measuring by ml/L it’s better because you get a more exact amount of nutrients, water contains a small amount of micronutrients (aka trace minerals) and due to your cannabis being directly exposed to the water, they will end up absorbing it. So when growing in either of these methods, we highly recommend measuring the pH and measuring the ppm of not only your nutrient solution, but also of the water source; Remember that water purity is very important when growing in hydro or aeroponics.
3. Plain Water or Nutrient Solution?
Hydrating a plant is one thing, however, feeding a nutrient solution is different and there are a few things to consider. The root hairs of a Cannabis plant only need to come into contact with a fine film of water to be able to tap in and extract what they need.
Feeding Plain Water Only
This is basically as organic and simple as one can be, as Mother Nature does all the rest. As all of the necessary primary and trace elements can be found in abundance inside an organic living soil, all that is required is to keep the moisture levels adequate for the living microorganisms. Compost also depends on specific temperatures and moisture levels in order for organic matter to break down over time.
Most growers who follow a nutrient feeding chart will feed a mix of different nutrients until the final few weeks. During the last part of the flowering cycle is the flushing period where plain water is fed to the plants for two reasons.
Break Down Undissolved Salts
The build-up of nutrient salts that can develop over a 10 week period or more can be quite excessive. Especially if using chemical-based nutrients that are designed for hydroponic systems.
Water is the source of life and is also a solvent in its own way, meaning the final 14 days will help wash away (aka flushing) the remaining salts increasing the flavor and quality of the ash.
Using Up The Reserve Nutrients
Even though it may seem a drastic change to switch from a maximum nutrient solution, it is necessary to starve the plant forcing it to use up all of the reserved nutrients. This is when Cannabis plants will begin to exhibit rapid deficiencies and is a sign the nutrients are being used up.
4. Oversaturating The Cannabis Grow Medium
There is nothing worse than having the best intention, but unfortunately, too much water or nutrients does not result in more growth, so overwatering or overfeeding your cannabis will have a toll on your plants.
In the event your growing medium is inadequate regarding drainage and water-retaining capacity, then the water evaporation can be very slow causing many issues to occur. Transpiration that occurs through the leaves will need to compensate for the excessive amount of water around the roots. As plants find a way of transporting water through foliage or the root zone, by oversaturating you are jeopardizing the integrity of the plant’s growth, causing stunted growth.
Also, wilting of the fan leaves is a clear indication you have over-saturated your root zone, and the plants are not happy.
This can also happen when underwatering, which is when your plant is lacking water. Even though underwatering shows the same trait, do not feed more water and allow your growing medium to air out until the pot is light to pick up. A cold and wet root zone will cause anaerobic bacteria to infect your garden and kill your cannabis. It is extremely important to keep your root zone oxygen-rich and one reason why felt pots are so popular. And when this happens, cannabis plants will fail to uptake certain much-needed nutrients if the water levels are too great.
Just like when watering in excess, feeding with a too strong nutrient solution will cause the minerals to build up and the results will be a lockout in nutrients and a line of deficiencies to begin occurring one after another. This happens because cannabis can’t use the excess minerals and they end up burning the tips of the leaves and can end up burning the whole leaf if not dealt with fast.
As the nutrient burn continues, the tips of the leaves will start to get brown, crispy, and sometimes twisted; This is very common when using bottled nutrients, that’s why it’s a good idea to look into organic feeding if you have access to them. This is where the importance of pH levels in water comes in; Maintaining pH levels in between the acceptable range (for each specific medium) is one way to avoid this kind of problem because the pH level can block the roots from absorbing the nutrients your plant needs.
So even if you’re feeding your plant properly, higher or lower pH may prevent them from absorbing them and result in similar symptoms as overfeeding but will actually be caused due to the lack of nutrients, known as underfeeding.
When your plants are suffering from pH problems or an excess of nutrients, flushing is the best way to solve your issues, and to do it correctly, you will have to water your plants with plain pH’d water.
This will correct the pH levels and wash off the excess nutrients in the medium and the roots, allowing you to start feeding your plants from scratch or correcting the pH level, allowing your cannabis plants to absorb the nutrients they need once again.
Top Tips for Marijuana Watering
So, if you’re a beginner grower here are a couple of tips to avoid having some of the problems cited in this article.
Know when to water by weighing the pot
A good way to calculate the watering ratio is to feel the weight of your growing medium when it is at the lightest with no water. This is the point your plants need to be each time before watering. By doing this you will always know when to water without running the risk of overwatering.
Use your finger to check if the medium needs more water
If you are hand watering and are not sure if the medium is wet enough, simply insert your entire finger down the side of the pot. Judge how moist or dry your finger feels and this should give you a clear indication of when next to feed.
Water plants with room temperature water
It is better to water plants with room temperature water (around 20-23°C), as cold water can cause shock and encourage a cold root zone.
Water your plants when the lights are ON or up to 30min before
Avoid watering close to lights out, as the plants will not get a chance to use it until lights are on. Humidity levels in the garden can increase and oxygen levels and temperatures around the roots will drop.
Best Recommended Heavy Feeders
For all the growers who like to give their ladies the best nutrients on the market, we have picked our 3 biggest feeders to keep you company in the grow room.
first time ever growing and got some amazing colors from this strain with low temps ran it at about 58-64 for 2 weeks and got this color
A rock-solid performer who can take heavy and frequent feeding, and she will grow big fat buds in return.
This is a resilient strain that needs that extra nutrients to be able to develop the big fat nugs so make sure you feed it properly, always keeping an eye out for signs of deficiencies.
I grew this with other fast buds strains. I’m very happy how they all grew. I use soil, 19L pots on a 20/4 light cycle. They love it.
When it comes to the biggest autoflowering cultivars around, this lady is certainly up there with extra-large yields and a big thirst.
This plant grows quite big for an autoflower and thanks to its Sativa heritage, it will need that boost when it comes to nutrients to be able to develop big and strong and be able to withstand the weight of the huge amount of buds during flowering.
I got 134g off this gal growing in 3 gal pot with 24 hours of light. i’m stoked with the result! Smells like diesel. Was a great grow overall.
Another big feeder who loves a high nutrient ratio, thanks to her Indica-dominant lineage. This strain grows quite stocky and produces huge yields, that’s why you should feed her properly, and in return, it will produce lots and lots of resinous buds and in a big quantity.
Just remember that despite being heavy feeders, you should always pay attention to any signs of deficiency and increase the nutrient dose gradually to avoid stunting growth!
7. Cannabis Crop Watering FAQ
How Much Should I Water My Crop?
While there is no exact answer to this question, with experience you will get to know how much watering your crop will need. The amount needed will be totally dependent on the stage of growth, the size and types of pots used, the intensity of the light, the cultivar, the environmental conditions, the health of the crop, and the style of cultivation. Keep in mind that it is totally fine to let the plants go without water for a day or two every now and then, and is actually recommended by many experienced cultivators. The thinking behind this is that when the roots run out of water they will spread out and go searching for it, resulting in a larger overall root ball. Remember bigger roots mean bigger plants, which means bigger yields.
How Do I Tell If My Plants Are Thirsty?
As mentioned above, a great way to tell if your plants are in need of watering is by getting used to the weight of the plants. Cannabis plants themselves don’t actually weigh that much, with most of the weight coming from the water trapped in the pot. If you pick up a pot and it seems super light, it’s probably time to feed. Another obvious sign that your crop is thirsty and ready for some water is drooping and weak plants. If your plant looks like it is struggling to hold itself up then there is a good chance it needs a feed, but proceed with caution here.
Why? Well, plants that have been overwatered will display similar signs. If you feel like you have fed your crop often enough for it to be healthy and it is still looking weak and lifeless then there is a high chase that you have actually overwatered. The best thing to do in this situation is to feel the weight of the pots and to let them dry out for a day or two to see if there is any improvement.
How Much Water is Too Much Water?
When watering cannabis plants, a good rule of thumb is to aim for about 20 – 25% of the pot size. So, say you are growing in 12-liter smart pots (which is absolutely perfect for autos) then you should aim to give the plant about 2.5 to 3 liters of feed water. Another way to judge the correct amount of feed water is the amount of runoff. You do not want to water the plants until the substrate is just moist without seeing any runoff, as this can quickly lead to nutrient saturation issues.
Every time you water your plants you want to see about 15 to 25 % of the water running off. It’s also important to be able to remove this runoff, a sitting water can lead to its own range of serious issues for your crop. Be sure that you have a system in place to easily remove any and all runoff, such as drip trays. Inclined trays work great, and a wet/dry shop vacuum can help immensely.
Is There a Timing Guide for Watering my Cannabis Crop in Terms of Growth Stage?
Again, as we have mentioned above, this is really dependent on a huge range of factors. But, as a very general guide, you can aim to water your crop in the following way:
: at least twice a day, if not three times. Seedlings prefer small, frequent waterings. Do not worry so much about seeing runoff here. plants: Daily or twice daily is the best protocol to follow if you are hand watering plants that are in the vegetative growth stage. plants: Plants that are flowering require slightly less water than vegging plants, but once a day should still work well. Some growers recommend 4 times per week, with a break every third day
8. In Conclusion
Having a reference when your growing medium is the most lightweight, is a great start point for a beginner grower to work with. Finding the balance of how much your plants are drinking as well as transpiring is a learning curve that can take hands-on experience and require multiple grows under your belt.
Once you find the perfect mix, your Cannabis plants will respond in kind, and remember less is more sometimes. And remember that if you were wondering how to water outdoor cannabis, the process is basically the same but you should be extra careful on rainy days.
For those of you who have the watering game on point, feel free to leave your tips in the comment section below to help out fellow growers!