Watering outdoor weed plants

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One of the most obvious factors of growing healthy outdoor plants is that you need to figure out how often should you water your outdoor weed plants. Unless you live in a place that allows you to grow cannabis freely, an essential part of determining your best watering method is secrecy and liability. You need to make sure that your watering system does not attract attention to your growing site.

So how much water will your outdoor weed plants need, and how will you deliver it to them? These are some of the questions that will be answered in this article.

How much water should I give my outdoor weed plants?

It’s impossible to determine the exact amount of water your weed plants will need without first knowing more about some other factors such as soil, weather, the intensity of the sun (the amount of light), and exactly what time of year it is. You will even need to take into account what exactly the strain type is like, and what stage of the growth cycle your plants are in.


If your weed plants are extremely tall, for instance, you will need to provide them with a large amount of water (multiple gallons per day). On the other hand, a smaller weed plant will need far less.

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Weed plants can absorb only a certain amount of water after a certain point, so whether you water them 30 gallons or an infinite amount of water, they will still grow at the same rate. This makes it especially important for you to pay close attention to what your plants’ exact watering needs are. You will be able to tell if your weed plants are not receiving enough water because their leaves will become dry and they will begin to wilt. If worse comes to worst, they could easily die.

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Try not to overwater the plants either, since it can make the plant have the same symptoms. You can tell the difference by checking the soil: if it’s damp, your plants have been receiving too much water. It is also a good idea to dig underground and see if you can locate any water reserves. This can be particularly tricky since the sun can easily dry only the topmost layer of soil. One way of finding out whether or not you need to be watering your plants extra is by simply checking the soil four days after you’ve watered. If it’s still damp, you do not need to add any more water.

When to water my outdoor weed plants?

Watering is especially important when your plants are seedlings. You need to make sure that the soil consistently remains moist so you will need to water frequently. After one or two months, you can cut back on the watering to a certain extent, as the soil should dry in between watering. That allows your plant’s new roots to be exposed to some air. The more your weed plants grow, the better their roots will develop.


The roots will become deeper and can access points of moisture and nutrients that are located further underground. Once the roots start to find these points of moisture, they will begin to follow the moisture as they grow.

This can lead to some difficulties, however, as it could make it difficult to identify when the older, more mature plants require water.

How often to water outdoor cannabis

As a basic rule of thumb, you can count on watering one time per week to ensure that your plants are getting enough water. Do it more frequently if you live in a particularly dry and sunny area.

Also read “How to get the best water for marijuana plants

You might also want to consider watering your outdoor weed plants more often if they are growing in an environment that has porous soil. Be especially aware of this type of soil if you live in the western United States, such as California, Arizona, or New Mexico. You won’t need to worry if your plants are near a source of water (such as a river), but otherwise, your soil will most likely have quite a low level of groundwater. This, coupled with the porosity of the soil, means your plants will require an extra amount of water to survive. 

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The best water sources for outdoor weed plants

If you can choose a site that is near to a water source, such as a river or stream, your life will be much easier. These locations keep the soil from drying up during the summertime. You won’t have to bring in buckets of water during the dry seasons, which would almost certainly arouse suspicion since it would be nearly impossible to conceal what you are doing.


Don’t be too laid back when choosing a river bed location for your marijuana plants. They come with their own security risks. Rivers tend to attract more than just animals and insects: they attract humans, too. Animals and insects might damage your cannabis plants by nibbling on their leaves, but humans could damage your entire crop if they discover it and report it.

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One way to avoid these risks is by planting your outdoor weed plants downhill from a river, rather than directly next to it. You can simply take a garden hose and run it from the river to your plants, using gravity as your only source of power. Be cautious, however: the pH level of the river should always be tested before you do this because water with an unsuitable pH level will not help you in the long run. You should also continue testing it throughout the summer, as the pH level can actually change. You can buy a pH meter or pH test strips at this link

Another painless way of watering your outdoor weed plants is by capturing rainwater in a large barrel or tank. You can also create more elaborate irrigation systems using rainwater, timers, drip systems, and pumps. Sometimes this is the best way to use nature’s resources to keep your plants happy and healthy while still keeping your growing site safe from discovery. Do not use this method if you are in an industrial area, however, as the rainwater could be too acidic to use for watering.

How to water outdoor weed plants

There is no single correct way of watering all outdoor weed plants since a lot depends on where they are growing and what their genes are. If your crop is not terribly huge, then you should easily be able to hand water without too much trouble. Lots of growers will carry water to their site themselves, then use hoses or watering cans to transport the water from larger containers to their plants. You can even carry water back and forth between a nearby natural water source and your own plants. This is often the best option, because not only is it convenient, but it also will lessen your liability since you won’t risk people seeing you and asking you why you are carrying gallons and gallons of water into the forest.

How to water outdoor marijuana plants
How to water outdoor marijuana plants

A larger crop of marijuana will make things a bit more difficult, however, as you will have to establish a more elaborate system of watering. This can include pumps that are powered by batteries or gas, which, of course, carries an entirely new set of risks with them. The motors on these devices are usually quite loud, which can be heard from miles away.

It isn’t exactly the best way of keeping your grow site a secret. They are also more difficult because they need a consistent power source and water supply. Sometimes they can be very complex and need to be designed intricately with lots of different tubes and platforms. They are useful for large operations, however since they have the ability to pump out huge amounts of water at whatever specific times you need.

Also read When is the best time to water your weed plants?

An alternative irrigation technique is called slow-drip irrigation. This does not require any expensive equipment and can be made at home. First, poke a few tiny holes into the bottom of a one-gallon milk jug. These holes will allow a bit of water out at a time and will be a steady drip for your plants to constantly be receiving small amounts of water.

How to water outdoor marijuana plants with bottle
How to water outdoor marijuana plants with a bottle

The only maintenance required is refilling the jugs. This method will be especially useful for growers who only visit their site once in a while since your outdoor weed plants will receive enough water over a long period of time without ever being overwatered. If it doesn’t provide your plants with enough water, all you have to do is add another water-filled jug. If the drip is too slow for your plants, simply make the holes bigger so it comes out faster.

Watering weed plants in your garden

Finally, in some cases, you can get by with only a regular, everyday garden hose. This will work best for growers who have just a few weed plants that are planted on their own property. Rainwater can also be harnessed for a cheaper source of water for your crop – assuming the rainwater is clean.


Many water systems clean the water with chemicals to make it healthy for watering weed plants and drinking. Because this could result in there being a chemical taste in the water, further chemicals are often added to take away this taste. Tap water can have a pH value of either above or below 7, which is perfectly fine for humans but not so much for our cannabis crop.

Also be aware of the sodium (salt) content as well, which could reduce your plants’ sizes by half if there is too much present in the water. Other things often found in tap water are chlorides, sulfates, as well as other solid substances. Distilling your tap water is always a good idea, especially when watering very young, delicate seedlings.

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If you are concerned about these factors, simply purchase a test kit at your local hardware store or gardening center. They can assist you in figuring out what the quality of your water is like, as well as which chemicals are most present in your water.

If you’ve been considering growing marijuana outdoors, buy high-quality seeds from our seed bank so you can get started.

Rainwater is one easy way of avoiding the chemical problem altogether. To catch rainwater on your property, just put some sort of large container beneath one of your drain spouts. Do this during the rainiest part of the year, which is generally the springtime. Plan well in advance. Assuming this water won’t have water-soluble chemicals in it, it will function very well for your plants. If you are not planting on your own property, the final step is figuring out how exactly you will transport it to your growing site.

FAQ about How often should I water my outdoor weed plants

How often should I water my outdoor plants?

When they’re seedlings, you’ll need to water them frequently to ensure that the soil is always moist. But you’ll need to cut back after a month or two.
Once they’re mature, you can water them once a week. However, you’ll need to do it more frequently if your environment has porous soil or you live in a dry and sunny area.

How much water does a plant need per day?

Weed plants have different watering needs. The amount of water they need will depend on various factors such as the strain of the plant, the weather, soil, and intensity of the sun, among other things.

How many gallons of water per plant?

It’s impossible to determine the gallons of water that each plant needs. Reason being, there are a lot of factors that need to be taken into account.
The best thing you can do is to pay attention to your plants to determine their watering needs so that you can always provide them with enough water.

Thanks for reading. Please leave comments or questions below and don’t forget to download my free grow bible

Happy growing!


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Robert Bergman

Robert Bergman is an Amsterdam-based marijuana grow expert who has years of experience from small grows to massive operations. His passion for growing led him to develop his own Gold Leaf strain. Now, Robert is dedicated to sharing his knowledge with the world.... [Read full bio]

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34 comments on “Watering outdoor weed plants”

  1. Hi All,
    New grower here. I am doing an outdoor grow here in Michigan, where its legal, so backyard growing is now a thing.
    I have 2 plants in separate Vivosun fabric bags full of Fox Farms Ocean forest soil.
    When filling the bags, I added a packet of yeast at the halfway point to help with the microbial soil.
    How often should I water and are nutes really necessary when growing in such a hot soil?
    Any info or opinions….., I thank you.

  2. Solid write up! Quick question. What is the main reason a female turns to male? Thanks and keep cool!

  3. Well that sounds all good but we are in a heat wave with little to no rain so should i keep my plant moist due to the condition and is it alright to use tap warter if you let it sit for a day

  4. Growing outdoors on your own land is totally legitimate in MA. Can we see some articles that make less hay about “hiding” your grow, and more practical information.

  5. This was a very helpful article. My plants are currently about 18″ tall and grow outdoor in southern california desert sun. This watering guide helps a lot!


  7. I live in the uk read your guide lines on watering and it was very usefull as I live in a a very high rainfull country { wales } yep wales not Ireland or Scotland or that other place England l.o.l but WALES WALES boyo

  8. haze,

    Yes you can. I let me seedling get 4-5 sets of alternating nodes (sets of true leaves), then I transplant to 1 gallon pots, if I am growing in soil or soil-less medium. You can transplant all the way until right before you transition to the bloom cycle.

  9. steve,
    There are so many factors that one needs to know when attempting to grow Cannabis. Download our free grow Bible and join our grow support forum. We have many knowledgeable growers there.

  10. first time grower just a few on the property so im in contact with them everyday, my question is, or should say my deliema is, i have hieght no width not alot of leaf i pinched the tops to slow down the height process to give tem a chance to grow more leaves.ps help i have no idea what im doing wrong ?

  11. Why are we told to handle plants carefully, especially during harvest, lest we knock off trichromes, yet torrential thunderstorm rain apparently does not remove any (according to your reply)?

  12. Perhaps we need to get together on terminology. Grow cycle generally means the vegetative cycle; While Bloom represents the Flower cycle of the plant.

    I suggest you download and read our Free grow Bible, and join out Free support forum. I can tell you that we can clarify and help you in the forum. I am left wondering exactly what method you are attempting to employ, and are asking about. See you at our forums. 😀

  13. Newbie wonders about “blanket covering” or total darkness for 12 hours during the grow cycle. Reason is please???

  14. Wow, amazing wobelg format! How lengthy have you been running a blog for? you made blogging glance easy. The whole look of your site is fantastic, as well as the content material!

  15. You will see that whom you might be dealing with, you might be bound that the inivuiddal is who they are saying they’re. The photographs are transmitted in real-time, making it that far more complicated to fake. Evaluate this to phone porn or conventional chatting, where guys have been recognized to fake to be girls and vice versa.VA:F [1.9.17_1161]please wait…

  16. first time grower .Growing 5 plants in pots amongst my flower and tomato garden.its august and plants are 2 feet high and 2 feet wide. i live on long island so not sure when the plant will flower. was watering a little every day ans some of my leaves were spotty brown while others are perfect. any tips for THE HERBMAN lol

  17. Hey Steve,
    Once pistils and buds are forming, you can add more potassium. I can only assume that you are growing in pots…? A lot of people like to flush when changing over to bloom nutrients. You only need to flush once, with 3 times the capacity of your pots. i.e. 3 gallon pot = flush with 9 gallons of properly ph’d water (6.5)

  18. Hey Guys! Enjoy all your articles and have used a lot of the same techniques in my outdoor grows.When do you think is the best time to change over to higher potassium fertilizers and do I need to flush with plain water for a couple of weeks before I change my mixture.This is my first year to concentrate more on a few indices.I am on a Kindle if some words misspell themselves.Anyway is there a certain change in the plant’s physical features (flowering) that should let me know to add the potassium? THANX a million.!

  19. Water does not remove tirchomes, or resin from the plants.

    This is why we can; When needed; Give our plants a “shower”

    Join our support forum for faster and more detailed grow info! 🙂

  20. I didn’t realize the Marijuana Plant Care Guide, was included along with the Grow Bible. Perhaps I read it in such gulps the first time, I simply don’t recall the latter, Plant Care. Karen