Learn the art of watering weed plants, how to avoid watering problems, how watering weed properly produces strong, healthy cannabis plants. 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 everything you need to know about watering your cannabis plants. No more guessing or worrying!
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.
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.
How Often Do I Water Indoor Marijuana Plants?
If you’re growing marijuana in soil or another growing medium like coco coir, you will have to hand-water your plants. Watering is an important part of growing cannabis indoors, and knowing how to water your plants will save you a lot of frustration!
How often do you give your cannabis water?
Well, you will want to water your marijuana whenever the top of the soil or growing medium starts to feel dry. I like to water when the medium feel dry up to my first knuckle, or about an inch.
- Soil – Water plants when the soil feels dry up to your first knuckle (or if the pot feels light).
- Coco Coir – Aim to water plants every 1-2 days. If coco is staying wet for 3+ days, try giving less water at a time until plants get bigger and start drinking more. Don’t wait for your coco coir to dry out, but don’t water if the top inch feels “wet”. If the container feels light, it’s definitely time to water!
How to water cannabis properly (when using a well-draining potting mixture with liquid nutrients)…
In soil, wait until the topsoil feels dry about an inch deep (up to your first knuckle – just use your finger to poke a hole in the soil and see if it feels dry).
In coco coir, you want to water every 1-2 days if possible and adjust the amount of water you give accordingly. The top inch doesn’t need to completely dry out between waterings.
If you’re regularly adding nutrients in the water, give enough water each time that you get 10-20% extra runoff water drain out the bottom of your pot. This prevents a buildup in the potting mixture because otherwise, you are continuously adding more nutrients to the system.
Go back to step 1. Note: If water takes a long time to come out the bottom, or if pots take longer than 5 days to dry out before the next watering, you may actually have a problem with drainage (more info below) or need to give less water at a time. If your plants are very small compared to the container they’re in, give water more sparingly until plants get bigger.
Growing in Super Soil?
- If you’re growing in super soil or another heavily amended potting mix, you may not need to add extra nutrients to the water because your plants can get all their nutrients directly from the soil.
- Any time you’re not adding extra nutrients in the water, you want to avoid getting runoff water because it will carry away some of the nutrients in the soil.
- Watering until you get runoff is important when using liquid nutrients because it helps prevent nutrient build up, but with super soil try to give just enough water that you wet the entire medium but don’t get extra water coming out the bottom.
Some growers swear by the “lift the pot” method to decide when to water your plants (basically wait until your pot feels “light” since the plants have used up all the water). It’s up to you to decide what’s easier for you.
I usually water my cannabis with a 1-gallon water jug for small grows, or 5-gallon jugs for larger ones. Runoff water is collected in the trays and after a few minutes I suck it all up with a small wet vac .
How to Provide the Water
When I first started growing, I gave my plants water using a watering can. A watering can works great, but it’s hard to water a bunch of plants with one watering can because you have to keep filling it up.
An old-fashioned watering can will get the job done, but they typically don’t hold a lot of water at a time, which is inconvenient if you’re growing a lot of plants
I personally like using a Battery Operated Liquid Transfer Pump to water the plants. You can pump water from a bigger container to your plants. This is a 3-gallon water container from Wal-Mart, and the pump just reaches the bottom.
My grow tent is 2 feet deep and this reaches the plants in the back. However, I don’t think the tube is long enough to reach the back if your space is deeper than that.
Some growers set up elaborate drip feeds to pump water if they have a lot of plants they can’t easily reach, both homemade or pre-made.
Let us know if there’s something we missed. Growers get creative!
How to Collect Runoff Water
It’s important to keep plants on saucers or trays so you can remove the runoff water. You can collect the saucers one by one and dump them out, but that also gets inconvenient with many plants.
It’s inconvenient to empty saucers one by one if you have a bunch of plants, but you don’t want to leave plants sitting in runoff water
If you put your plant on plastic trays, and then put the trays on a slight incline by putting something small underneath in the back, it will catch all the runoff water and cause it to drain to the front. The item in the back only needs to be about half an inch thick, for example a piece of plywood. However, if you can find something more water-resistant, like plastic, that’s even better.
These 1’x2′ plastic plant trays work well if they fit your space. You can fit four of them in a 2’x4′ grow tent (this is the grow tent I use) with up to two plants each as long as your plant containers are 11″ wide or smaller at the base.
Put trays on a slight incline by placing something underneath the tray in the back. This causes all the water to come to the front for easier collection. Each of these trays has a small plastic board (which we found around the house from something else) under the back. Anything that’s about half an inch high will do the trick. These particular trays accommodate plant containers up to 11″ wide at the base.
Not sure how to remove runoff water after watering your marijuana? Wet vacuums can be a great choice, especially if you already have one in the house. I didn’t have one, so I got Bucket Head attachment which can turn any standard 5-gallon bucket into a wet vac. You can buy one online but it’s $10-15 cheaper if you get it in person at a Home Depot. Another similar option is the Power Lid, though it’s also a bit pricey.
A downside to the Bucket Head is it’s a little loud, just like most wet vacs. Luckily you only need to use it for a few minutes after watering your plants!
Removing runoff water is a great start to make sure you are watering your cannabis plants perfectly, but it’s also important to…
Make Sure Pots Have Good Drainage
It’s very important to make sure that water can drain freely from the bottom of the pot, otherwise, the plant can get waterlogged and become overwatered (causing the plant to droop).
In addition to making sure the actual container has drainage (holes on the bottom, or some other way for extra water to escape), it’s also important to make sure your growing medium drains freely. If it takes several minutes for the water to come out the bottom of your pot when you water, it means that there isn’t enough drainage in the actual growing medium (it’s too dense, so water is having a hard time getting through).
How to improve the drainage of your growing medium
- Never use dirt you find outside. Chances are it does not have the correct properties for vigorous cannabis growth.
- Mix in extra perlite to loosen the soil and allow water to drain through more easily.
- Bark or wood chips are not the best choice for growing cannabis plants, even though they’re sometimes recommended to improve drainage in soil for some types of plants. On that note, avoid using soil that contains bark or wood chips. What makes soil good or bad for growing cannabis?
- Use Smart pots – these fabric pots help get oxygen to your roots (which gives you faster growth) and this type of pot makes it harder to overwater your plants. A cannabis plant growing in a tan fabric smart pot is pictured to the right.
This is an example of great soil for growing for cannabis – rich, composted, and well-draining
Composted super soil lets you grow organic marijuana without any extra fertilizers or nutrients
Watering Too Often? Barely at All?
In the beginning of your grow, you will likely be watering your marijuana plants every couple of days. Watering every 2-3 days is optimal for a young plant. If it’s taking too long for your plant to dry out, you may need to give less water at a time until the plant is growing faster.
If you feel like you are watering your plants too often, you may need to give more water at a time. You can also move plants into a bigger pot (which holds water for longer).
If plants take longer than 3-4 days to dry, make sure your potting mixture has good drainage and consider giving less water at a time
If plants are drying out in 1 day or less, try giving more water at a time or transplanting to a bigger pot
Speaking of pot size, it is generally best to start young cannabis plants in relatively small containers (like a solo cup with a few holes cut out of the bottom for drainage), and move plants into bigger containers as they get bigger. Starting in smaller containers makes it a lot harder to overwater your plants when they’re young, and makes it easier to flush plants and/or respond to problems if they occur.
That being said, you can plant your seeds right into their final container. Just be careful not to overwater your seedlings at first if they’re in a big container as they’re not drinking much water in the beginning.
If you started your plants in a solo cup, I’d recommend moving to a bigger pot once the plant is a week or two old, as soon as the leaves reach the edges of the solo cup.
10-20% Extra Runoff Every Time You Water (if you’re providing nutrients in the water)
Every time you water your plants, make sure that you provide enough water to get about 10-20% extra run-off out the bottom of the container, especially if you’re feeding additional nutrients in the water.
Sometimes soil and soilless growing mediums like coco coir start to collect natural salts from fertilizers that never get washed out.
These built-up salts can eventually cause nutrient problems, pH problems, and nutrient lock-out if they’re not removed on a regular basis.
Making sure you keep adding water until you get run-off is also a great way to make sure that your plants are draining properly.
Plus, this practice will immediately alert you to any drainage problems, (as mentioned earlier, cannabis likes well-draining soil) because you’ll be able to notice if the water takes a long time to come out the bottom, or doesn’t come out at all.
Different Nutrients for Different Stages of Life
First, make sure you’re using proper cannabis nutrients for your growing medium. They should be formulated for a plant like tomatoes, and they should have a different feeding schedule for the Vegetative (Grow) and Flowering (Bloom) stage.
If using nutrients on a regular basis by adding them to your water, it’s generally a good idea to give your cannabis plants nutrients every watering. This ensures the amount of nutrients in the plant root zone is kept relatively stable. If you notice the tips of leaves getting burnt from nutrient burn, it may mean you need to lower your overall strength of nutrients. Most nutrient recommendations on the side of the bottle are too strong for cannabis plants, and should be cut in half unless plants appear pale or lime green (which means they want higher levels of nutrients overall).
If Growing in Composted or Amended Soil, Give Just Enough Water That the Soil is Wet All the Way Through
When growing in composted and amended soil, the soil itself is made to slowly provide nutrients to your plant throughout its life. However, if you’re regularly watering until you get a significant amount of runoff, you’ll also be washing away some of your nutrients.
This is good when the plant is getting the nutrients directly in the water, to avoid unwanted buildup in the soil, but try to avoid a lot of extra runoff if you want your nutrients in the container to last until harvest.
Therefore, when growing in amended soil you should only water until you get just a drop or two of water runoff out the bottom. You want to ensure you gave enough water to reach the bottom of the pot without letting a significant amount of water run out the bottom.
Proper watering practices will greatly help reduce the amount of salt buildup and prevent nutrition problems from occurring.
If your cannabis plants shows signs of drooping, often the plant is getting too much or too little water, but not always. Drooping can be caused by….
- Too much water at a time, or giving water too often
- Not enough water at a time, or giving water too infrequently
- Drooping can also occur in hot conditions, or when it’s very humid or dry because the plant isn’t able to move water properly through the plant.
- Plants sometimes get droopy if they are given a lot of water after being allowed to dry out for too long, due to the stress of the water pressure quickly changing at the roots.
- Drooping is almost always associated with something going on at the roots, but plants also tend to put their leaves down a bit right before the lights go off, as if they’re preparing to “sleep” for the night. That can sometimes be mistaken as drooping when its actually part of the plant’s natural rhythm.
In order to prevent over or under-watering, make sure you water thoroughly every time (don’t just water a tiny spot in the middle of the pot unless you plant is very small for the container). You should be getting 10-20% extra runoff water every time if you’re adding nutrients in the water. In soil, wait to water again until the top inch of the growing medium feels dry, up to your first knuckle or so. In coco coir, aim to water the plants every 1-3 days if possible, and don’t let the top completely dry out between waterings.
Underwatered Marijuana Plants
- Wilting is the first sign of underwaterd marijuana plants
- Leaves are limp and lifeless, they may seem dry or even “crispy”
- Will eventually lead to plant death if not corrected
Overwatered Marijuana Plants
- Drooping / Curling is the first sign of overwaterd marijuana plants
- Leaves are firm and curled down all the way from the stem to the leaf
- Will eventually lead to leaf yellowing and other signs of nutrient problems if not corrected
If your plant is experiencing “the claw” and not just normal drooping (like the ends of leaves are just pointing down like talons, then you may actually have a nitrogen toxicity (too much nitrogen).
Nitrogen Toxicity (“The Claw,” tips bent down, dark leaves)
Learn more about Nitrogen Toxicity