Choose another country or region to see content specific to your location.

Lunar Calendar - Cannabis and the Moon

18 January 2023
How the phases of the moon can affect your cannabis outdoors.
18 January 2023
12 min read
Lunar Calendar - Cannabis and the Moon

Read more
  • 1. The moon cycles
  • 1. a. Ascending moon
  • 1. b. Descending moon
  • 2. The moon phases
  • 2. a. New moon
  • 2. b. Waxing moon
  • 2. c. Full moon
  • 2. d. Waning moon
  • 3. High and low tides
  • 4. Does the moon really influence cannabis plants?
  • 5. Moon and the constellations
  • 6. Tips for growing cannabis plants with a lunar calendar
  • 6. a. Root days (taurus, virgo, and capricorn)
  • 6. b. Flower day (gemini, libra, and aquarius)
  • 6. c. Leaf day (cancer, scorpio, and pisces)
  • 7. In conclusion

The moon has a direct impact on all beings, by paying attention to the phases of the moon you can take advantage to improve plant growth outdoors. Originally people used the lunar calendar to tell the different times of the month before there were ever calendars we know of today. You may be asking yourself why am I reading about the moon when I really just want to know how to grow cannabis seeds. Well, people think that the moon has more to do with the growth than what appears to the eye let's see if that's true and if it really relates to cannabis. Even though a real study has not been done on this subject, we all know that the moon affects tidal activity, and plants are mostly water so read on and learn all you need about cannabis and the moon. Now you must be asking yourself does moonlight affect flowering?

At first, the idea that the moon could have any effect on your cannabis plant whatsoever seems bizarre and outright false. However, many growers of cannabis, vegetables, and other plants plan out their gardening activities based on the cycle of the moon. In fact, this practice goes right back into ancient history. Some cultivators suggest that the moon influences plants in many different ways, including immune function, wound healing, regeneration, and growth. Despite these claims, and understandably, some researchers maintain a skeptical stance on this issue. But is it true? We need plenty more scientific studies to determine the truth, but some veteran cannabis growers obtain excellent results by following this methodology. Read along and find out!

1. The Moon cycles

The movement of the moon makes its distance from the earth vary, to be able to see this, you should be at an exact point and the next day at the same exact point you’ll be able to see if the moon is ascending or descending.

Ascending moon

When the moon is ascending, the sap rises to the upper parts of the plant and it’s the best time to cut clones off your cannabis plant. You should also avoid harvesting because the buds will be full of liquid and, as you may know, cannabis buds need to be dried so this can end affecting the drying process. 


Lunar calendar: moon cycles

How moon cycles happen.

Descending moon

A descending moon means the liquids flow downwards and increases the underground activity of all plants, this means it’s a good time to do things related to roots and to germinate seeds. This moon cycle is also the best time for soil enrichment, so if you’re making your own super soil or composting, now would be the best time to do it.

2. The moon phases

The lunar phases refer to the visible shape of the moon we see from the earth when it’s lit by the sun, just like the moon cycles, the moon phases can also affect plant growth.

New moon

A new moon begins when the moon cannot be seen from earth and ends when the right half of the moon is fully visible. In this phase, it’s not recommended to do anything else other than prune or slightly defoliate your plants if they are diseased and really need it.

Waxing moon

A waxing moon takes place between the new moon and full moon and it can be distinguished because the visible part of the moon starts crescent (looking like the letter C) and takes a shape similar to the letter D, meaning the moon is increasing its visible area. In this phase, the internal activity of plants is increased, strengthening your cannabis against pests and disease, during this phase it’s not recommended to prune.


Lunar calendar: moon phases

The phases of the moon.

Full moon

As you may know, a full moon is when the moon is completely visible and the liquids inside your cannabis plants will rise to the upper parts, during this phase it’s not recommended to prune or defoliate but it’s highly recommended for germinating seeds.

Waning moon

A waning moon means the moon starts looking like the letter D and is going back to a new moon, so the visible part of the moon is decreasing, meaning you will see it taking a C shape.

Have in mind that the D or C shape only applies to the northern hemisphere, if you live in the southern hemisphere it will be the opposite, so the crescent phase will have a C shape and the decrescent phase will have a D shape.

During this phase, the liquids inside go to the lower parts and the soil is much more active and the terpenes, flavonoids, and cannabinoids are better preserved so it’s perfect for harvesting, watering, or amending the soil for your cannabis plants but also means that germinating or transplanting is not recommended.

3. High and low tides

High tides and low tides happen due to the moon’s gravitational force, depending on how far the moon is from the earth, it could result in a high tide (closer to earth) or a low tide (far from the earth). Every day we experience 2 high tides and 2 low tides, so this can also affect what’s better to do during the moon phases.

Knowing these in combination with the moon cycles and phases will let you know exactly what you should or shouldn’t do. For example, if the moon is decrescent and the tide is transitioning from low to high (rising), it’s better suited to compost, improve hard soils and take clones or, if the moon is crescent and the tide is transitioning from high to low (falling), it’s better suited to transplant, amend your soil or improve loose soil.

Environment and Temperatures

The moon has a huge impact on the environment which is directly correlated with plant health and all other life on earth. The moon has control over the weather because tides and tidal currents help mix cold arctic waters with warmer waters in the tropics. This balances the temperatures and stabilizes the climate all around the world.

The moon also allows us to predict future weather throughout the weeks and months which will help greatly when gardening outdoors. Most importantly the moon keeps our planet at a tilt of 23.5 degrees, this allows the planet to function properly without serious temperature fluctuations. In the past, the earth's tilt changed one-two degrees and scientists have speculated that it could have caused ice ages. Without the moon, the earth's tilt would be changed drastically causing it to rotate anywhere from 10-45 degrees.


Lunar calendar: tides

High tides vs low tides.

The tides happen in the morning and the afternoon, although the low tide in the afternoon is more powerful than the low tide in the morning and the high tide in the morning is stronger than the high tide in the afternoon. Each tide takes around 6hs to go from high to low or low to high, the transition from high to low is called falling tide and rising tide when it goes from high to low.

Daily rhythms

You should also have in mind that the earth’s energy can vary depending on part of the day. 

When the sun goes down the Earth rests so it “inhales” energy and revitalizes, just like we do,  making it ideal to plant, transplant, or prepare the soil.

In the morning, the Earth “exhales” energy and is ready to “work”, making it ideal to germinate or harvest your cannabis plants.

4. Does the moon really influence cannabis plants?

As said above, there aren’t scientific studies proving this theory but farmers have been using this and other techniques for years and years.


Lunar calendar: influence

Cannabis plant under a full moon.

Way back, farmers needed to make the most out of their crops relied on nature because they didn’t have technology like we do now so they had to learn how the sun, rain, the moon, and other natural factors affected them. Another thing you should have in mind is that it depends on where you live, for example, the moon will have a greater influence if you’re in the northern hemisphere or southern hemisphere but as you get closer to the equator, it will have less influence.

Moon and the constellations

Another practice used by farmers is to plant according to the constellations in which the moon is passing at that time and knowing how that specific constellation influences cannabis so here’s a table to help you understand this better.


Aries, Leo, and Sagittarius Germination
Gemini, Libra, and Aquarius Flowers
Cancer, Scorpio, and Pisces Leaves
Taurus, Virgo, and Capricorn Roots


As you may know, the zodiac signs are based on the 4 elements of nature so as you can see in the table above, you can benefit in certain parts of your cannabis grow cycle if you do it at the right time.


  • Aries, Leo, and Sagittarius are the constellations of Fire, better suited for germination.
  • Gemini, Libra, and Aquarius are the constellations of Air, better suited for the flowers to develop.
  • Cancer, Scorpio, and Pisces are the constellations of Water and is when the leaves and stems grow more.
  • Taurus, Virgo, and Capricorn are the constellations of Earth and is when the roots will develop faster and healthier.

Tips for growing cannabis plants with a lunar calendar

Now that you know everything you need to have in mind, here’s a resumed guide to lunar planting to facilitate the understanding, remember that you should look at all the information above and look at the calendar to know what's recommended to do.


Lunar calendar


Also, it's recommended you download an app or look online for the exact information (moon cycles, phases, and tides)on where you live.

Root days (Taurus, Virgo, and Capricorn)

Whatever phase the moon is in the deciding factor when planting outdoors will be temperatures. Everywhere around the world has different growing seasons and I would recommend you get an idea for your local seasons to predict when you should start growing. The average month for starting plants outdoors is early summer but that depends on whether you are planting your seedlings directly in the ground or in pots.

Seeds Directly In the Groun

  • Germinate seeds directly in raised bed or ground in early summer
  • Sprouts should take about 4-5 days to show leaves
  • Once true leaves reveal themselves you will have nonstop vigorous growth

When planting directly in the ground the plant gets the opportunity to grow as big as genetics allow. This is exactly why you don't have to start the plants indoors during late winter. It is always good to note that the roots of the plant are around three times the size of the plant. As the saying goes “Bigger roots bigger fruits!!” But growing cannabis plants directly in the ground comes with many more benefits than mere size. It gives your plants the chance to interact with the native soil. This can be an advantage or a disadvantage at first, depending on what your soil is composed of. Ideally, it will hold a large amount of clay and organic matter; both of these substances feature a net negative electric charge and therefore hold onto plant nutrient cations such as ammonia (a form of nitrogen that plants need to make proteins).

Next, native soil—depending on its quality—is also loaded with beneficial microorganisms, including bacteria and fungi that help to feed plants by breaking down organic matter and cycling nutrients in the soil. Beyond tiny microbes, outdoor soil also contains other soil food web members, including worms. These vital lifeforms are amazing at cycling nutrients and physically pulling organic matter down into the soil, shredding it up, and releasing nutrients. They also release nitrogen into the soil as they move around, and many other nutrients, in the form of worm castings. Even if your native soil isn’t ideal, you can create amazing fertility in a short period of time by using dead mulches, living mulches, and no-till methods. 

Seeds Planted In Nursery Pots

  • Germination in late spring
  • Plant sprouts early by mid-spring in small nursery pots to allow you to bring them in and out on cold nights.
  • Wait to transplant till the root tips show at the bottom of the pots and the plant has exceeded 4 inches tall.

Prepare the soil 

When growing outdoors, you will have to prepare the soil, when doing this, it’s better to do it when the moon is descending, even better if it’s just before the new moon phase when it’s coinciding with the Earth constellations.


The germination process is better suited when the moon is descending, preferably 3 days before a full moon, and combined with an Earth constellation, this will result in faster and healthier growth.


Lunar calendar: root days

Germinating according to the constellations.

Feeding with a nutrient solution 

Now, if you’re watering with a nutrient solution, you should also do it when the moon is ascending and crescent but when the moon is on Taurus, Virgo, Capricorn, Gemini, Libra, and Aquarius. Have in mind that feeding is always better in the morning and avoid doing it when the moon is on Aries, Leo, and Sagittarius, which are Fire signs.

Defoliating and pruning the roots 

If you need to defoliate to improve light penetration or airflow between the buds, it’s best to do it on Flower days, with a descending moon in a waning phase. Now, if you need to prune the roots you should also do it with a descending moon in a waning phase but on a Root day.

Watering with pesticides or fungicides 

If you’re watering your plants with a pesticide or fungicide, it’s recommended to do it during the descending cycle in a waning moon on Root days.

Flower day (Gemini, Libra, and Aquarius) 


If you’re looking to transplant, you will have better results if you do it when the moon is in its crescent phase and in combination with an air constellation such as Gemini, Libra, or Aquarius.


If you don’t want to lose a certain cultivar or have a mother plant where you take cuttings from, it’s recommended you do it on a Flower day with an ascending moon in an either waning or increasing phase.


Lunar calendar: flower days

What you should do during flower days.

Best moon phase for harvesting

We would highly recommend against waiting to harvest until the descending moon. The only way to know when to harvest is based on trichomes. You yourself can harvest for the desired effect based on trichomes but most growers will try to harvest with at least 95% milky trichomes which will give you the highest content for cannabinoids.

 Let's say you want to wait another week to harvest because you want to have that amazing harvest moon but guess what, the plant is not going to wait for that moon. The plant will keep ripening which will then make the trichomes become amber, amber trichomes have a much heavier and couch lock-like effect. With the amber trichomes comes the degradation of THC and terpenes so please y’all harvest based on the microscope, not the moon. 

Leaf day (Cancer, Scorpio, and Pisces)

Foliar feeding 

If you’re foliar feeding, it’s better to do it when the moon is ascending and crescent, and when the moon is on Cancer, Scorpio, or Pisces, which are the constellations good for leaves.


When performing plant training it’s better to keep stress to a minimum so if you’re doing it during the vegetative phase, it’s recommended you do it with a crescent and ascending moon in a water constellation or Leaf day. Now, it’s not recommended to perform plant training but if you need to do it, it’s recommended to do it in a waning and ascending moon on a Flower day which is a water constellation.


Lunar calendar: leaf days

What you should do on leaf days.

Foliar pesticide or fungicide 

If your plants are suffering from a mold or bug infestation (or you just want to prevent them), you can get the proper genetics for your region. In most cases, if you buy seeds that already are resilient to fungus, powdery mildew, and certain types of insects you won't ever need to apply foliar application for pests and pathogens. We always prefer not to spray our plants with chemicals. 

7. In Conclusion

Smoking weed on a full moon or smoking moonrocks at night has nothing to do with the lunar calendar and cannabis, although moonrocks will take you on a trip to the moon and back.

If you’re an outdoor grower, now you know how the moon can affect cannabis plants, you will be able to plan ahead and make the most out of your plants while keeping them healthy and happy.

If you grow outdoors and know any more tips or tricks to help fellow growers, leave a comment in the comment section below!



External References


Lunar Calendars, Living the Lunar Calendar. Journal for the History of Astronomy. - Mccluskey, Stephen. (2013).