Growing cannabis in harsh climate conditions

Although cannabis performs well in many latitudes, a rigorous selection of the genetics that we’re going to grow is sometimes necessary in some places in order to harvest our plants successfully, especially outdoors. In this article we will focus on two classic, adverse climate conditions: cold and humid areas – like Northern Europe – and hot and dry climates, where the different cannabis seeds won’t develop in the same way.

Cannabis strains for humid and cold climate

While high humidity promotes a lush and healthy growth, things are different during the flowering stage, when flowers can be infected by mildew and other pathogenic agents due to the effect of cold temperatures and rains. However, it isn’t impossible to grow in these regions, and many growers from places like the Netherlands, UK, Germany, Canada or even Alaska successfully harvest their outdoor cannabis crops every year, mainly thanks to an accurate selection of the genetics grown – always looking for the most resistant strains – and of course the use of greenhouses, greenhouse heaters, etc.

Before presenting you a brief list of this type of genetics, especially suited for outdoor growing in these areas for being particularly resistant to moulds, we are going to explain a few desirable traits that might ensure the best possible results.

Cold temperatures do not allow buds to get fat

Cold temperatures do not allow buds to get fat

  • Damages caused by excessive moisture are normally favoured by a lack of air and stagnant moisture. Thus, you should avoid plants with compact structure and dense flowers. A more Sativa structure will allow plants to better withstand these conditions; rain is frequent in these latitudes even from the end of summer. Better air circulation within the buds and the plants avoids problems with moulds, so looking for strains with airy buds is recommended if you live in a humid, rainy area.
  • The best environmental conditions are over when frost and rains arrive, so early, fast flowering genetics are the best choice for these climates. In this sense, automatic cannabis strains are also an excellent choice since you can easily know harvest time and set the correct period for bloom (summer).
  • Tropical strains can’t withstand cold temperatures. Thus, genetics known for being resistant to cold should be your first choice.

Next we detail some strains known for their adaptability and resistance to cold temperatures and high humidity:

  • Feminized seeds: Easy Sativa, Belladonna from Paradise Seeds, Snow Bud High Altitude, Biddy Early from Serious Seeds, AMS, PCK, Shaman, Passion, Frisian Dew, Green Poison.
  • Regular seeds: Early Queen from Mr. Nice  Biddy Early , 2 Pounder , Pakistan Chitral Kush from Cannabiogen, Bangi Haze from Ace Seeds, Shaman, Passion, Nepal Jam.
  • Automatic strains : Dark Devil from Sweet Seeds, Moby Dick Auto from Dinafem , Hobbit Auto and Afrodite from Kannabia, Auto New York City from Pyramid Seeds, Tundra #2 from Dutch Passion, etc.

This list is not too exhaustive, but it contains a nice number of strains which are characterized by their adaptability to humid climate conditions and early flowering, which are the main traits to look for to get a successful outdoor harvest.

Cannabis plants adapt to the environment

Cannabis plants adapt to the environment

And remember:

  • It’s always recommended to enhance their resistance to moulds by applying different antifungal products and organic plant stimulators.
  • You should also avoid particularly humid areas like ponds, rivers…
  • Growing in greenhouses represents a good alternative, offering a slightly wider choice of strains (especially in terms of flowering time).

Cannabis strains for hot, dry climate

Sativa marijuana strain with aerated buds

Sativa cannabis strain with airy buds

Cannabis in its natural condition also grows in dry areas, but in this case we normally speak about landrace varieties, that is to say, pure genetics which have adapted to this type of climate over generations and that naturally resist heat and drought. However, not all cannabis strains are adapted to these conditions and sometimes they perform better if grown indoors or in less sunny latitudes. Thus, a correct choice if you live in hot, dry areas is also crucial for a successful harvest.

These are the main traits that should be taken into account for this type of climate:

  • Indica strains usually have large, broad leaves, a trait which leads to higher evaporation of the moisture contained in the plant through the leaves than Sativa marijuana plants.
  • Indica varieties generally produce dense and compact buds, which are more sensitive to heat and could develop moulds if relative humidity rises.

The following list contains suitable genetics for dry climates:

  • Feminized Seeds: African Free from Eva Seeds, Karamelo from Kannabia Destroyer from Cannabiogen, Early Maroc from Philosopher Seeds, Maroc, Caprichose Thai from Elite Seeds.
  • Regular seeds: Mango Zamal, Krystalica from Mandala, Pakistan Chitral Kush or Sandstorm from Cannabiogen,Spice, Kalichakra, Congo or Old Timer Haze from Ace Seeds…

Here you have some tips for growing cannabis in hot climates:

  • Add polymers to the growing medium in order to improve its water retention capacity, also put some straw or any type of mulching on the surface of the soil to limit water evaporation.
  • To protect the root system, grow directly in the ground or in large, white plant pots (you can also wrap the pots with some isolating material to control the temperature of the root system). Smart Pots, thanks to their improved aeration of the substrate, will prevent root problems.
Cananbis plants perfectly adapted to the hot climate of Senegal

Cananbis plants perfectly adapted to the hot climate of Senegal

  • In “Guerrilla” crops you can put the plants in a partially shaded area. Bloom won’t be as abundant as if they were placed in full sun, but the need of water and nutrients are highly decreased! You can also put a layer of plastic with some holes in it on the grow spot and cover it with a layer of 5cm of soil to reduce evaporation.
  • Use shading mesh to protect the flowers and limit the exposure to sun, which helps to control temperatures.
  • A soil rich in micro elements and microbial life enhances the defenses of plants and their resistance to stress. Use Green House Feeding Enhancer, Bactohemp or Bio Supermix to protect the roots from stress and pathogens.
  • Products like Vitalink Chill help the plants to withstand hot temperatures.

We hope this article will help you to successfully harvest your plants wherever you’re growing!

Happy harvest!

December 19, 2017 | Outdoor cannabis growing
12 Comments


12 comments on “Growing cannabis in harsh climate conditions

  1. Fredy John Smith

    A very good and comprehensive list depicting the right species of marijuana that can fit into the adverse environment.
    Thanks for the info.

    1. Dani Alchimia

      Hi Fredy,

      Glad you found it useful! Thanks for your comment!

      Best!

  2. willem kooistra

    wat van soort wiet zaden kun je het beste gebruiken hier in nederland .is voor buiten kweek en het liefst met zo hoog mogelijke thc .en een kleiner gehalte cbd . en waar niet zo gauw top rot in komt . kunt in mij daar raad in geven wat voor zaden daar in aanmerking voor komen . kom uit het noorden in drachten dus genoeg regen gehad dit jaar. met heel veel top rot in mijn planten

  3. GM

    Great Blogs brother,
    Looking for HIGH CBD / LOW THC Hemp feminized strains good for humid conditions (Florida).
    Any suggestions

  4. Shawn

    I grow outdoors and I’m having problems with some kind of mold but it has been wet and high humidity is there anything I can do to prevent the problems

    1. Tim Alchimia

      Hi Shawn, thanks for your comment. If you could tell us more about the kind of mould problem you’re having maybe we can help a bit more. However, there are certain preventative measures we can take to prevent fungal attacks in general. Firstly we have a wide range of organic and chemical fungicides, although I would only recommend using organic products at this stage of the season, as the flowers will be starting to develop.

      We can use Potassium Silicate or Horsetail to provide more silicon to the plants’ cells, which physically strengthens and reinforces them against mould. A good IPM (Integrated Pest Management) program will help to keep fungus at bay, eg. regular spraying with neem oil & aloe throughout vegetative growth.

      We can also improve the plant’s air circulation to reduce the chance of mould problems, by pruning away the lower branches and leaves that won’t get as much light, which directs the energy to the top parts of the plant and allows better air movement around the plant.

      I hope that helps, if you provide us with a bit more information we can probably give some better advice. All the best and happy growing!

  5. Arnaud

    Greetings alchimia,

    Im growing outdoors, critical 2.0, and following your blog, Im at the 7th week of flowering (out of 9 cause critical 2.0 is indica based) and I started to witness oidium on some of the buds, Ive cut what I could to avoid the oidium spreading on my plant and salvaging what I could.

    I wanted to know if i could still salvage the rest, and what would be the consequences on the rest of the buds and on the plant itself, I know cutting some buds even parts of the branches of the plant can induce some stress especially at this stage but what do i risk exactly ?

    Im sad about it but there is not much I can do , the oidium isnt that spread out althu I had to cut about 15g worth of buds (and the best and biggest ones 🙁 )

    1. Tim Alchimia

      Hi Arnaud, thanks for your comment and question. I’m very sorry to hear you’re experiencing powdery mildew, it can be very disheartening after all the hard work of the growing season, I know from personal experience!

      You can read more in our blog post about powdery mildew, including a few treatments and techniques for avoiding it in the first place, but you can definitely act to help salvage the rest of the plant. In some cases, I’ve sprayed my plants with a hydrogen peroxide solution (1 cup of 3% H2O2 in 1 gal water) which helps to slow the infection and to kill spores, without leaving any residue at all, meaning it can be sprayed right up till harvest day. Another recipe for spraying which I’ve used with success over the last few years is Aloe Vera & Epsom Salts (1 cup fresh aloe juice & 15ml Epsom Salts per gallon of water) which can be used right up till the last week before harvest.

      It’s very, very difficult to eradicate PM from a plant once it’s established, and unfortunately, the most effective treatments are chemical and toxic, so completely unsuitable for application on cannabis plants in flower. For this reason, it’s vital to take preventive measures, keeping the plants in optimum health, taking care with the environment surrounding the plants and implementing a regular IPM (Integrated Pest Management) regime in veg.

      It’s too late for this year, but for next season, I heard recently from a trusted gardener that BioBizz Leaf Coat was very successful in preventing outbreaks of PM in a grow room that had previously caused some problems in this respect. I’m definitely going to give it a try on a few plants next year, the mildew seems to be getting worse with each season.

      I hope that helps, all the best and happy harvesting!

  6. Arnaud

    So, would u recommend any product in your shop that I could buy ? the non chemical ones please ?

    1. Tim Alchimia

      Hello again Arnaud, thanks for the question. Yes, I’d recommend trying Fungone by Aptus, a natural fungicide that’s safe to use up till the last week before harvest. It’s basically a super-charged and much more effective version of hydrogen peroxide.

      Another product that claims to be safe during flowering is Flower Fytosave, a natural phytovaccine against PM. I haven’t had a chance to try it for myself yet, and it appears that it may have a more preventive effect, although it ought to stop an existing infection from spreading.

      As I mentioned previously, it’s very difficult to get rid of powdery mildew once a plant is infected, so as well as treating this year’s plants, also start thinking about next year, planning ahead to prevent it becoming a problem again. One of the most important factors is the genetic resistance of a plant to PM, and unfortunately, Skunk-based varieties like Critical are quite prone to mildew infection. Have a look at our post on mould-resistant varieties for some ideas.

      I hope that helps, all the best and happy harvesting!

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