Growing Medical Marijuana in Hawaii

Growing Medical Marijuana in Hawaii

How to grow marijuana outdoors all year round in Hawaii. When to start seeds for the subtropical long and short seasons.

Hawaii’s medical cannabis program allows registered patients to grow up to ten plants at the patient or caregiver’s property. While this doesn’t seem like a whole lot, remember that it’s year round growing in Hawaii. There are ways to maximize yield from only a few plants by using additional lighting and crop cycling methods.

hawaii's grow seasons

growing cannabis in hawaii icon

Seasons, Daylight, and Additional Lighting

Let’s discuss Hawaii’s growing seasons and how the daylight hours affect the growth of the cannabis plant. We’ll answer some frequently asked questions such as the right times to start (germinate) seeds during the different times of the year.

As you may already know, cannabis plants react to seasonal changes. This trait is called photoperiodism. Basically, the plants grow and will bloom depending on the light hours seen per day.

Indoor growers can manipulate this trait to control the size and life cycles of their plants. In essence, they control the seasons with grow lights.

Outdoor growers are subject to the sun’s daylight hour schedule. This is why you hear many Hawaiian growers talking about when’s the best time to start seeds.

long-season hawaii

Long Season Natural Growing (Without Lights)

The long season is the same spring to fall growing season the rest of the northern hemisphere is on. That means cannabis plants growing in long season use spring for vegetative growth and summer/fall for blooming.

Hawaii is located at about 20° N on the map. The daylight hours in Hawaii range from a high of 13.5 hours in the summer to a low of about 11 hours in the winter. Growing without lights, you can start seeds anywhere from Spring to mid-Summer to catch onto the long season.

Long Season vs. Short Season
Cannabis plants will grow faster in the long season and slower in the short season.

sativa long season

When to start Sativa strain seeds in Hawaii?

Sativa strains started too early may grow woody and weak by the time they are ready for harvest. On the other hand, starting sativa strains too late will result in plants that end up blooming through winter and re-vegging into spring.

Start sativa seeds or sativa dominant cannabis seeds as early as even February for long-flowering sativa strains such as Asian, African, Central American and Hawaiian varieties. Most Hawaiian growers start seeds on the dark of the moon in April.

indica long season

When to start Indica strain seeds in Hawaii?

Indica strains started too early may not grow according to the long season and end up finishing around June or July as stretchy buds. That’s why it’s better to start the fast flowering indicas a little later than the big sativas. However, starting indicas too late will end up bringing the plants budding into winter, where yields are reduced and humidity dangers are increased.

Start indica seeds or indica dominant cannabis seeds anywhere from April until July to catch onto the long season. The dark of the moon in May is the best time to start indica dominant strains.

hybrid cannabis long season

What about hybrids?

50/50 sativa/indica hybrids or breeds close to that ratio tend to grow more like an indica than a sativa, so use the indica strain germination guidelines for best results.

Start hybrid seeds anytime after February until July. Hawaii is in the northern hemisphere, so the standard crop start-til-harvest plant cycle is the same as other places in the USA.

harvest cannabis

When will the plants finish?

Cannabis plants growing in the long season typically finish from August to November, depending on each strain’s flowering time. Some long flowering sativa strains will even keep budding into winter, such as Thai strains. Here are two considerations to make before planting:

  • Everyone is going to have bud in November, so you can beat the flood with a fast-flowering strain that finishes in August.
  • Or, you could go big with a pure sativa strain. These plants will grow larger than most and yield enormously, although they take a very long time to finish.
growing marijuana in hawaii big island mauna kea
Up at 2600 ft on the Mauna Kea

short-season hawaii

Short Season Natural Growing (Without Lights)

The short season is the season that plants catch onto if you start the seeds in late summer or winter.  The plants grow slower in short season and end up producing buds in the winter, spring and early summer.

Why is that?

The reason that plants grow slower in the short season has to do with two factors.

  • Decreased daylight hours
  • Colder temperature (at high elevations)

Cannabis plants that are not supplied with enough light during the vegetative growth cycle will grow slowly, almost stunted as it starts its life off in what is essentially a flowering room.

Depending on the time of year and the amount of sativa genetics a plant has, you will be lucky to get 4–6 foot cannabis bushes naturally in the short season.

Some just go for quantity
Lower yields, smaller plants and slower growth, local guerilla growers combat the short season by putting out a much more massive volume of plants in the fields.

sativa short-season

Growing Sativa strains in the Short Season

Certain sativa strains have dealt with short seasons all throughout their genetic history. Through natural evolution, the plants have developed methods to grow and reproduce in the warm tropical winters around the world.

However amazing this trait may be, growers are often disappointed with short season sativa plants due to the very stretchy, airy buds that they produce in the winter. On top of that, most sativa strains will jump on the chance to grow again for the long season once it hits early spring. That means all of your buds will re-veg and end up rotting on the plant. You can do light deprivation techniques to stop this, although it’s easier to just plan ahead.

By using any of the popular sativa dominant hybrids instead of a pure sativa, you can finish in the safe window, which is harvesting around Dec to Feb. As a rule of thumb, the only time you’ll want to grow sativa strains in the short season is if you can get them to finish before March.

indica short season

Growing Indica strains in the Short Season

Indica strains are quicker to grow, but most indica and indica dominant strains simply don’t get enough light hours in the winter to grow big. A lot of growers end up with what we call lollipops: a stick in the ground with one bud.

Your best bet is to start the indicas around late summer to fall. That way, the plants can get bigger than if they were started in the winter. As we get into December it dips to under 11 hours per day which makes it really hard for plants… they’ll just sit there and not grow.

hybrid cannabis short season

Growing Hybrid strains in the Short Season

Sativa domiant hybrids do best: The most rewarding option for natural lighting, short season cannabis growing is to use is sativa/indica hybrid strains. The sativa dominant 60/40 and 70/30 cannabis strains perform well in the Hawaiian short season. Sativa genetics will help the plant vertically, while the indica genetics will help prevent vegetative morphing during Jan–May.

additional lighting harvest hawaii

Additional Lighting for Multiple Harvests

What is most rewarding for the medical marijuana grower to do in Hawaii is supplement extra hours of light by using grow lights. If you keep the total daylight hours above 16 hours, most strains of cannabis will continue to grow in vegetative growth status and won’t start flowering until you stop providing them the extra light.

Why provide extra light?

So you can harvest buds whenever you want. Using extra light in Hawaii replicates indoor growing, giving you the option to control a plant’s growth cycles and size.

The plants can be grown outside during the day, soaking up the sunlight for free. Then before sunset (or alternatively, before sunrise), put them under grow lights for a few hours or the whole night!

How to do this?


1.) Set up a grow room, or outdoor cannabis arena: You can have your plants in pots and carry them in to a grow room, or grow in a greenhouse/covered outdoor area and have lights turn on for the plants as the day ends. This will keep them in vegetative growth as long as you keep doing this daily on schedule.

2.) Calculate the total hours of daylight and add up to 18 You can check daylight hours online-  Then add the number of hours under lights. Plants in their vegetative growth cycle should be provided more than 16 hours of total light per day. This will give you fast growing plants that stay in veg (they don’t flower).

3.) Keep on the lighting schedule daily: Interruptions in the vegetative plant’s growth cycle will trigger the flowering cycle prematurely. Even missing one day should be avoided. Try getting a friend to do it if you’re busy.

5.) Induce flowering: Simply stop providing the additional lighting, and the plants will start their flowering process. Refer to your strain’s flowering time to estimate when you will harvest buds.

6.) Make a calendar (optional): Rotating clones or seeds on a schedule works great for harvesting year round. Knowing your strains flowering time, you can easily make a scheduled bud harvest that finishes exactly when you want it to.

That’s it! Now you can harvest the crip pakalolo (quality cannabis) every 30 days, 45 days, 60 days, wheneva.  Mark dates on your calendar to cut new clones or plant seeds, transplants, flowering and harvest.

are led grow-lights good for cannabis growing in hawaii?

Are LED grow lights worth it for Hawaii?

LED grow lights are a good option for many cannabis growers, especially due to the high price of electricity in Hawaii. LED grow lights do not use much power and deliver the right kind of light needed by cannabis plants to grow. The secret to these efficient LED grow lights is that they are designed to output only the most efficient spectrum of light that absorbed by plants, while ignoring other light frequencies that cannabis does not use in photosynthesis, such as green light.

300W Galaxyhydro LED Grow Light

The best bang for your buck LED light, this 300w Galaxyhydro LED is for serious growers who want save on money and power, but still demand vigorous growth from their plants. Expect to see drastic improvement in your speed of growth using additional lighting with a good led light—you will be able to easily pump out multiple harvests quickly and efficiently. Don’t get ripped off by overpriced lights in magazine ads, this one does all the work for a fraction of the price.



Once you have your grow light set up, you can control how big you want your plants to be and when they will finish. When you are ready to start flowering them, simply remove the additional lighting. As soon as this is done, the plants will react to the sudden change in daylight hours and start the flowering process, no matter what time of the year it is in Hawaii.

Sativa or Indica?
Most all popular sativa and indica hybrids can finish any time of the year outdoors in Hawaii, with the exception of heavy sativa strains.

Pure and landrace sativas have naturally adjusted to the seasons and will be eager to stretch out and hook on to long season if you try to finish them in late spring/early summer. Quick flowering 60/40 sativa indica strains are the preferred choice for high-yield production all year round.


small LED grow light

If you really are low budget, or using a small solar system, these little lights will do the job for cheap. These small led lights are under $25 each and are only using 12 watts of power. Kinda silly if you think about it but these little LED lights actually do a better job than the equivalent match in fluorescent bulbs. Put one or more over a few clones, and as they get bigger, use a single light for each plant until they 2 feet plus. Buy 4 lights and your only at 48 watts power draw.


using grow lights hawaii

Better LED Grow Lights

Read Next: Top 25 Best LED Grow Lights

Update 2020

We’re trying to introduce a bill for the legalization of cannabis seeds throughout Hawaii. More details soon, you can check out Hawaii Cannabis News for related information.

What are your favorite grow methods and strains for cannabis growing in Hawaii? Leave your strains and comments below. Aloha!

Continue reading on the Weed Blog

42 thoughts on “Growing Medical Marijuana in Hawaii”

  1. Hello,

    My name is Shane Ostergard. I am a licensed Medical Marijuana patient in Washington State. For over a year I have been learning how to grow cannabis. My plan for Fall was to start WWOOFing in Hawaii, This position could be a good fit for me. Thanks.

  2. Aloha everyone,
    This is the Minister of da sense. I have been around a long time. If you are older, you might recognize the handle from the old days on the Cannabisworld message boards. I have been cropping the cripplers for almost 30 years now. 25 of those years I have been growing in Hawaii. I lived on Maui for 17 years, but now grow on the Big Island. I have been here for 10 years now. And I have pulled off some serious cobs over the years. I have been living in the Puna district for about 7 years now. And to be honest, it’s the toughest place to pull off ripe buds because of the mold. I had never even seen mold on my plants until I got setup out here. I have had my heart broken many times due to mold, and I am at constant battle with mold. It’s a real bummer that I have had to give up many strains I grew for years. I have found that it is mostly about the strain you are growing. The best herb I have ever seen, was some that I grew out in Hawaiian Acres. A strain called the “Death”. It is almost totally immune to mold problems. And the buds are as dense and killer….so potent that even an old school fool like me would be sweating, mumbling, too stoned to accomplish much. In people with a lower tolerance, they often go into panic attack mode, some people have even gone to the ER thinking that the herb was laced. lol I figure that is why they call it the death. Although it takes about 11 weeks to finish out. Anyway, I am having to start all over again thanks to some asshole who literally robbed every thing of value on my old property, when I had to go to the mainland for a family emergency. I am currently running the “Blue Dream”, and a few other strains that turned out to be molders. So I am scrapping them and giving the Blue Dream a shot at long season. However, I lost my contact for the Death….and I am wondering (hoping is more accurate) that someone else out there has a line on the Death? I think that it is not only the best strain in Puna, but the best I have ever seen. The only strain I liked as much was the Diesel I brought from Maui. Shoots….please get at me if you’re familiar with this strain. Mahalo 🙂

    • Aloha Minister,

      Nice to hear from you…

      This “Death” strain you are describing sounds quite similar to a variety we call “Vietnamese Black” – a sativa that will make your heart race with paranoia. An intense high comparable to mushrooms. Extremely mold resistant, and able to finish up hard and dank outside in the pouring rain.

      With the 11 week flowering time, “Death” is likely a hybrid of “Vietnamese Black”, may be a local kept goodie, but check out these strains with “VB” in their genetics.

      Black Maui

      Orient Express

      I’ll ask around the Island for this “Death” strain, as you have got me interested as well now. Stay in touch and we’ll see what we can find.

      Feel you on the mold loss problems. We have dealt with the same moldy disasters many times. Being here for 30 years, I’m sure you know how trying to finish buds in humid climates can be.

      I also am a big fan of Diesel. She performs well for us, hardy towards the outdoors and has yielded higher than many strains grown side-by-side. My standby cash-cropper plant.

      Good story,

      Shoots brah!

    • Aloha Bruddahs, I also live in Hawaii on the Big Island but I’m located in Ookala (Mauna) at roughly 2,500 ft elevation. I am currently on my first grow but I have a big worm farm that I’m using for my beautiful gurls. Before moving to Ookala I also lived in the Puna district but in Kalapana-Kapoho. Anyway is there a place I can volunteer at to Help ( really to be a student and learn proper out door technique) grow medical marijuana? I love that growing Medical Marijuana is so Simple and so Complexed at the same time. My love for growing medical marijuana has started me growing a lot of other Froots(lol) and vegetables on my 6 acre lot here in Ookala. I can be reached VIA email @
      Much Love and Peace

  3. 1 Tablespoon of Vitamin C powder, ascorbic acid, in 1 gallon of water. Sprayed on Plants or Buds, eats powdery mildew. Does NOT harm Trichs or flowers. Can save yer ass.

    Shoots, thanks for the info. It very well could be a relationship to the VB. I have only seen the Death in Puna. It’s also a very tasty strain, very skunky, but a different kind of skunky, kinda hard to explain. I forgot to mention the molokai frost, that was a great strain for Puna too. I would top em and they would finish out bushy with dense popcorn buds all over. But anyway, thanks for the reply. And if you come across the Death, LMK. And also, get it if you can. I am sure that you will be impressed. In the meantime, I am counting on the Blue Dream to come through….it sounds pretty good. I have not tried it though. Well, Shoots. Take it light Braddah. Aloha!
    The Minister

  5. Aloha Puamana,
    I have just noticed the tip for the powdery mildew. Thanks for the info. I am going to try that for sure. I am disabled, and not able to do as much as I used to….and was needing a greenhouse. And low and behold, as my Christmas present, my youngest son came out with my granddaughter for Christmas, and as a present, bought and brought all the material, and built me a greenhouse for my Christmas present. So,…this is a great help when the plants are 6 weeks into flowering, and it rains pitchforks and hammer handles for a week and a half.! It’s a big help in stopping the dreaded gray mold/bud rot. But it’s not much help with the powdery mildew. Thanks again for the tip. 🙂 peace and prosperity to all!
    The Minister

  6. 1st off, most or all ascorbic acid is made from gmo corn. Not what I want on my plants!

    For mold and mildew, consider a regimen of Serenade and Actinovate. Both are OMRI listed. Also neem in veg.

    But of course, mold resistant strains will be the best bet!

  7. Aloha JK. I have your books, and we met once long ago…I used to camp out near Makena at Changs back in the day. Man, I would be surprised if you hadn’t come across the Death out in Puna at some point. Have you ever been able to sample it? Just curious. Shoots. I wish a productive long season to all. Aloha 🙂

    p.s. Dumb automatic spelling correcter thing. It supposed to say Minister of da Sinse. lol

    The Minister.

  8. Also I forgot to ask. I see all of these interesting strains….but it’s looking like they are all feminized. I am specifically in need of non feminized seeds. I have been breeding for years, and was forced into a temporary hiatus….but am now ready to get back into the action, and I am hitting a brick wall of feminized seeds. Looking to the future, it’s a disturbing trend.

    The Minister

    • Granddaddy Purp is regular seeds, it’s a killer quick finishing hardy indica strain. Does well inbred as well as making crosses. I crossed Granddaddy Purp with a Hawaiian Sativa and got great results. Anything by Sensi seeds you can get regular as well, I recommend Early Pearl.

  9. This is a great article I learned a lot especially about mold resistant strains, thank you for sharing this and bringing me one step closer to growing my own marijuana!

  10. What is difference between indica and sativa?.
    What precautions we have to take while consuming this breed?.
    Is every person need is different as per his/ her physiology?

  11. Aloha!

    Great site you have here, it is always nice to see more ‘Ohana representing Hawaiian Pakalōlō.

    We were directed to your site by a member of our ‘Ohana who said someone was using “puamana” as their name and commenting on your site. The comments above from user “puamana” are in no way shape or form affiliated with Pua Mana ‘Ohana or Pua Mana 1st Hawaiian Pakalōlō Seed Bank.

    While spraying vitamin C, or garlic oil on your plants may dissolve some powdery mildew and mold, there is only one tried and true way to grow Pakalōlō in Hawai’i with minimal issues arising from mold due to the high humidity here on da Hawaiian islands: grow HAWAIIAN Pakalōlō strains!!

    Hawaiian landrace strains such as Puna Buddaz, Maui Wowie, Moloka’i Purpz and Kaua’i Electric have spent hundreds of years acclimatizing and adapting to the unique tropical environment we have here in Hawai’i and are your best bet in ensuring a bountiful Hawaiian harvest.

    When you are building a grow room indoors the 1st thing you do is create the ideal environment for your Pakalōlō plants; temp 72-78 degrees, %55 humidity at max, you also can also enrich with co2 and you control the light schedule.

    When growing outdoors the exact opposite is the case; the 1st thing you do is choose the ideal Pakalōlō strain for your environment!!!

    As anyone who has ever lived on the Puna side of da Big Island can attest, you can not even throw your clothes in a laundry basket for 3 minuets in Puna without your clothes being eaten alive by mold.

    Puna Buddaz (da real Hawaiian strain, not the strain “Puna Budder” released by T.H. Seeds that is a Hawaiian x Afgan imitation under a similar name) is an amazing survivor and true legend in da Pakalōlō kingdom. She handles da tropical monsoon downpours of da Puna District on da Big Island of Hawai’i like a champ. Many Puna growers will tell you after particularly rainy seasons, Puna Buddaz is da last plant standing when many other strains have already succumb to mold issues.

    Puna Buddaz is a very special lil lady and is our #1 pick for growing mold resistant strains in Hawai’i. Puna Buddaz even performs well for our mainland ‘Ohana on da west coast who have grown her in OR and CA with great results. Puna Buddaz flowers in 55-60 days amassing heavy loads of resin and trichomes, perhaps another reason she beats da mold is her fast flower time.

    Our 2nd and 3rd place picks for growing mold resistant strains in Hawai’i are: Moloka’i Purpz and Kaua’i Electric.

    Moloka’i Purpz gets her lovely purple hues from being cultivated high (literally) atop the tallest sea cliffs on Earth on da island of Moloka’i. She can handle cold temps and is no stranger to tropical rain.

    Kaua’i Electric received her name after hanauna (generations) of cultivation by local Pakalōlō growers up Powerline Trail on da island of Kaua’i. Powerline trail is located on your way up Mt. Wai’ale’ale. Mt. Wai’ale’ale is da rainiest place on da planet Earth. Kaua’i Electric can handle whatever tropical rain is thrown her way and she will not only survive, she will thrive.

    Maui Wowie cultivated in Hana Maui for hanauna (generations) is another great choice for mold resistant Hawaiian Pakalōlō genetics as Hana is da rainy side of Maui similar to da Puna side on da Big Island of Hawai’i. Maui Wowie is a Hawaiian landrace who originates from Lower Nāhiku Maui and was given her catchy name at a solstice celebration thrown by Bradda Joseph of Lower Nāhiku Maui during the 1960’s. While countless imitators have used da name Maui Wowie to peddle their Pakalōlō, true Maui Wowie can be identified by her sweet tropical taste and smell, her psychedelic mind boggling effect and her ability to resist mold and mildew in tropical climates.

    Just because a strain is Hawaiian does not mean it will be mold resistant. Kona Gold is a massive Hawaiian sativa from da Kona side of da Big Island. Kona is a very dry sunny climate allowing Kona Gold to reach her massive potential. Kona Gold flowers in 10-14 weeks allowing more time for mold to set in and is not suitable for rainy tropical climate zones like Puna, but she thrives in da Hawaiian sunshine and is one of da largest most potent Hawaiian sativa strains on Earth.

    Where ever you happen to be, it is always a wise call to find a Pakalōlō strain that has acclimatized to your environment. Here in Hawai’i we have a very special climate and our Pakalōlō is a direct reflection of da paradise we call home.

    Keep up da good work with your site and your grow,

    Aloha a hui hou,

    <3 Pua Mana 'Ohana <3

  12. Hey, cool. I’m glad people are adding comments and good information. I had several strains that I had worked on for years, but some person took my seeds, never knowing the treasures they possessed. PUA MANA, I believe I had the Maui Wowie strain to which you’re referring….however, it was know to me as the Pink Gorillas, or the Gorilla Pinks, depending on who you were talking to. Being from Nahiku, it is guarans mold resistant, as was the death. I have tried some seeds a hippie guy gifted me, but they weren’t spectacular. I was pondering on ordering some seeds, but being on disability and making in a month what I usually made in a week, is making that a non option for me at.this point. I have found some old seeds that I made, but not exactly sure what strain, and they’re at least 3 years old. But I am hoping for the best. Good luck to all.
    The Minister

    • Aloha Minister!

      Da Puna Death Bud and Pink Gorilla are both great island strains from da old school. Another epic Maui strain from back in da day you may remember was called: Galactica. Our ‘Ohana in Hilo just got us some seeds of da Galactica we are about to start playing around with.

      If financial issues are a hurdle to getting the seeds you need no worries…Pua Mana ‘Ohana can…;-)

      We are working on organizing a Hawai’i Blue card seed giveaway for patients here on da islands. Our attorneys have not green lighted the project yet but as soon as they do we will be freeing up seeds for patients on Big island, Maui, O’ahu and Kaua’i.

      Aloha a hui hou,
      Pua Mana ‘Ohana

  13. Aloha Pua Mana.!
    I’m glad to hear from someone else who is familiar with some of the old school Hawaiian strains. I don’t remember the galactica…But I became pretty good friends with Bully D. I lived up in Kanaio, and he would ride his motorcycle out there a lot, and I hooked up with the Blood. That was also an awesome strain.

  14. Pua mana, I agree with some of the information you spread but… A couple things are miss information. First off, Joseph from Nahiku didn’t live on Maui in the 60’s, he lived in la Jolla and moved to Maui in the 70s. He moved to lower Nahiku in 1983. And marijuana wasn’t introduced to the Hawaiian islands hundreds of years ago. Some say it was brought by “the brotherhood” in the 60s. We on the eastside here still have the “keanae pink gorilla” (an original swazi) and hold it close to the circle. No disrespect intended, just clearing things up. Aloha

  15. Re: Pua Mana, wow…. Just went on your web site and read “your” history of pakalolo. Very interesting indeed. Though your right…. As powerful, resourceful and medicinal of plant as pakalolo. Hawaiian history would be filled with dances and chants and kahuna knowledge protected from kapu. It was a good read.

  16. Hi there, I recently graduated with my medical degree and I’m looking for opportunities as a wwoofer on a Cannabis Farm before my medical internship. Cannabis is something I am passionate about and would love to learn more and more about it. Can u guide me to a farm that might be looking for someone like me?

  17. Yessah! Running jack herer and gelato og from seedsman along with some (molokai pakalolo) seeds i scored from da expo


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