Lunar Calendar - Cannabis and the Moon

How the phases of the moon can affect your cannabis outdoors.
24 November 2020
8 min read
Lunar Calendar - Cannabis and the Moon

  • 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.

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? 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 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.


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.

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 SagittariusGermination
Gemini, Libra, and AquariusFlowers
Cancer, Scorpio, and PiscesLeaves
Taurus, Virgo, and CapricornRoots


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)

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

Opposed to popular belief, harvesting during a full moon isn’t the best practice. Ideally, you should harvest your cannabis plants during a Flower day with a descending cycle and during a waning moon, preferably in the morning and coinciding with a low tide because the low tide means all the liquids inside the cannabis plant will be on the lower parts and you will have better results when drying your buds.

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 do it during the whole ascending cycle but it’s better to do it during a crescent moon in Leaf days, preferably in the afternoon.

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).

24 November 2020