How to Germinate Cannabis Seeds in Water (2024)

Water, not surprisingly, is by far the most basic need when it comes to growing plants. Starting cannabis seeds in water with a good soak is a time-tested technique used by cannabis cultivators the world over and for good reason. All types of cannabis seeds, including your favorite regular, feminized, and autoflowering varieties, can be started using this method.

Why germinate cannabis seeds in water?

Germinating cannabis seeds in water is very popular. It is easy and straightforward, letting you get growing without delay! Soaking a seed in water until its radicle (the small white root) pops out lets the grower see that the seed is viable in the conditions provided. It’s the most obvious sign that germination has begun and growth is underway.

Are there any downsides to starting seeds in water?

There are only a couple of cautions for starting marijuana seeds in water. First, the sprouted seeds can drown if they stay in water too long after germinating.

Avoid this by being prepared for the next step and checking on seeds at frequent intervals.

Second, seeds germinated in water need to be transferred to another growing medium to continue developing into young plants. This can leave sprouted seeds open to damage if handled roughly or exposed to unclean environments.

If you want to have a handy one in all document about germinating your weed seeds, I recommend to download Bergman’s Grow Bible. You can download it below!

Can I use tap water to germinate cannabis seeds?

Generally, clean tap water is an acceptable choice for germinating cannabis seeds.

It is often recommended to allow excess chlorine in city water to evaporate before using tap water for gardening, including starting seeds. While there are good reasons to embrace microbial diversity in all growing phases, drinking water treated with chlorine to eliminate potentially harmful bacteria and fungi does not generally contain enough chemicals to harm or inhibit germinating seeds.

Tap water varies in quality and character. If a municipality provides it, it should have been treated according to local consumer protection regulations and standards. Still, the grower has no way of knowing additional information without performing tests.

Even when safe to drink, both city and well water can contain chemicals and minerals (be it “hard” or “soft” water) and pH levels outside of optimum levels for cannabis gardening.

Check our guide on how to prepare water for cannabis gardens for a more in-depth look at this subject.

How does water affect cannabis germination?

Inside a mature seed, the living cannabis embryo depends on its hard, shiny shell to prevent rapid changes in moisture.

Cannabis seeds are built to resist losing and absorbing water until the conditions are right to germinate. Once they begin to soak up water from their environment – a process called imbibition – all of the other natural steps to growth will follow.

Since each of these steps involves the specific biology of cannabis, you can imagine that if the water “tastes” wrong, the seed may not read the environment as especially welcoming.

What kind of water works best?

Clean, distilled water works best for germinating marijuana seeds. It is consistent and generally free from unknown substances, so you do not have to question whether the water affects your germination results.

Step-by-Step: How to germinate cannabis seeds in water:

Time: 8-24 hours

Difficulty: Beginner-friendly

Step 1

Assemble the following:

• Good quality cannabis seeds
• One clean container per seed variety, big enough to hold about 1/2 cup (125ml) of water
• Splash-proof label(s) and pen
• Clean water at a comfortable room temperature

See Also

How to Germinate Autoflowering Cannabis Seeds

Step 2

Pour clean water into your chosen container. (can be anything from a glass to a plastic bowl. As long as it is CLEAN!)

Step 3

Drop each cannabis seed into the water and notice whether it floats or sinks. Don’t worry if every seed doesn’t sink to the bottom right away, but do give the container a little swirl or use a disinfected poking tool (your finger, the non-writing end of your pen) to submerge them and get all sides of the seed wet.

Step 4

Label the container with the following info:

• weed seed name and origin
• number of marijuana seeds being started
• date and time seeds were started
• ambient temperature
• water source/type

(Bonus points for taking a photo of your label: it’s a backup you can easily reference in the future and means you are already forming good record-keeping habits. Of course, if you are growing under severe prohibition, don’t digitally snitch on yourself by using a phone camera that connects to a network).

Step 5

Step 6

Set a timer or otherwise leave yourself a reminder to check on your weed seeds after 8 hours of soaking. When the time comes, check on your seeds. Note if any have already “popped” (or “emerged”). Once the small white rootlet (the radicle) leaves the safety of its shell, it will be looking for a place to establish as a sprout.

Step 7

Part b) Transfer all germinated seeds to the growing medium of your choice.

Step 8 (if necessary)

Reset your timer/reminder system for 24 hours from when you originally started soaking. Evaluate your success to this point. If any of your seeds have not yet germinated, consider repeating Steps 6 through 9. If you’re getting mixed results with weed seeds from the same batch, you may wish to sow the remaining soaked seeds directly in the chosen growing medium to keep them moving along the same timeline.

Step 9

If none of your seeds have germinated after 48 hours, consider using a simple scarification technique to gently push them in the right direction.

Tips for germinating cannabis seeds in water

Do:

• Choose a container that is a reasonable size. It should be big enough to hold the number of seeds you are germinating without the seeds touching one another. It should also be easy to get your seeds back out again (not too deep for tweezers, nor too narrow for your hand) and not be easy to knock over.
• Keep the packaging your marijuana seeds came in. Even if you germinate all of your seeds, holding on to the original packaging for the lifetime of those plants allows you to keep track of important details (source, seed name, whether it is feminized and/or autoflowering, etc.).
• Document your marijuana grow. You might be surprised by how easy it is to forget what time you did something, which seeds are which (you can’t tell by looking!), or what methods and tools worked best in your specific situation.
• Be Positive! Even if you don’t go in for “vibes,” starting cannabis seeds is exciting. Enjoy every step of growing cannabis, learning as you go, and you will get more out of the experience than can be weighed on a scale.

Don’t:

• Rush, panic, or assume your weed seeds are dead if they don’t germinate right away. There are natural reasons why healthy seeds sometimes take longer to sprout, and you can try some simple techniques to encourage their germination.
• Expect precise consistency. Seeds from different sources can develop on different timelines. Even seeds that came from the same plant can vary.

A Note on Cleanliness

When starting cannabis from seed, remember you are always working with living entities. Microbes, including bacteria and fungi, are present in all but the most highly sanitized (pharmaceutical or laboratory-level) environments. Some of these are companions to cannabis and will help your seeds to thrive; others will reduce the likelihood of your seeds germinating.

Because a cannabis seed contains food energy reserves, it is adapted to protect itself from competing microbes. These often thrive in the same general conditions (warm, moist) as your young beans. For that reason, it’s wise to remove as many potential sources of contamination as possible. This includes everything: your water, container, hands, and the seeds themselves. Provide a clean space to germinate marijuana seeds and give them the best start to life.

Final Thoughts

Germinating seeds in water is how a lot of people get started growing cannabis. While every batch differs, recently produced good-quality cannabis seeds are generally robust and inclined toward rapid germination and development.

If you think two steps ahead, you can plan to have the supplies and time organized to give your seeds the attention they deserve. Consider this part of making a friendly first impression, setting the tone for the healthy relationship you’ll develop with these plants throughout their growing lives!

Until next time, may you and your garden keep growing together, higher and higher!