Can I grow cannabis outdoors in the UK?

Yes you can!

An amazing amount of cannabis does grow without problem outside in the UK! And as we know weed that has been grown in the sun is always going to be better than weed grown using artificial lighting.

Guerilla growing (growing weed in the ‘wild’) is quite popular – costs are low and it can be done almost anywhere. The south of England is better, but plenty of fine weed has been grown outside in the north of England, Scotland and even Wales.   Recent improvements in autoflowering strains mean you can grow cannabis plants in just 9 or 10 weeks and without too much bother.

If you have a nice private back garden, all the better. If not, you can always consider guerilla growing.

Sensi Seeds Purple Bud Automatic is popular outdoors in  the UK. Check it out here

Other strains proven to grow well in cold climates like the UK are:

Passion Number One from Dutch Passion –  a simple to grow indica that thrives outside in the UK. The dutch have been apparently growing this outdoors since the 1980’s – in their cold climate.

Early Skunk from Sensi Seeds – an easy to grow very high yielding indica variety with body stone – ideal for beginners.

Frisian Dew also from Dutch Passion – This strain is half indica half sativa and again will thrive outside in the UK.

Purple Maroc from Female Seeds –  A sativa that produces lots of resin and finishes very early, does well in the UK.

Biddy Early from Serious Seeds –   Award winning early finishing plant.

Related: The Ultimate Guide to Growing Autoflowering Cannabis

Plants are normally started outside in in April – although recent arctic conditions would suggest this isn’t sensible. May perhaps! You could also start plants inside, as they don’t need big lights to start with – a simple florescent light can be used to start them.

Flowering generally begins in August or September, depending on the strain and can take several weeks at the least. Some plants will not finish until October – some strains such as Purple Maroc or autoflowering strains will finish much earlier, lessening the chances of mold affecting the buds, or hitting a frost. You also get your bud earlier!

Take a look at all of Sensi Seed’s autoflowers here.

The Sensi Skunk Auto is getting rave reviews from outdoor growers.

Never plant seeds directly into the soil. It’s much better to grow the plant in a controlled environment for 4-8 weeks before slowly introducing them to an outdoor space by increasing their exposure by a few hours each day before replanting or leaving them outside permanently.

Consider also that plants grown in pots will generally not grow as big as ones grown in the ground, so if you have to use pots consider using Smart Pots or similar. I have just tested these and found them to be amazing, indoors and outdoors.  They are what’s used in many big US grows though you’ll find them cheaper than on amazon.

They allow for air pruning of the roots. I will never use a normal pot again after personally seeing the results of plants grown in these pots. They are known as aeration containers and the bigger the better.  If you want to grow a kilo outdoors, this is definitely one way to go.

J Arthur Bowers Multi-Purpose Compost with added John Innes‘ is a highly recommended compost.  Perlite is often added to compost to help it hold moisture.

Plant Magic Plus is also getting good reports.

The plants will need different types of fertilisers when they are in their different stages, flowering requires different nutrients to the initial vegetative stage. Some plants are also heavier feeders than others. You can buy organic fertilisers for this Bat shit (Guano) is also a good all round organic fertiliser.  I generally avoid chemical fertilisers.

You may also want to investigate using molasses – specifically black strap molasses.  Some people only use molasses. You just put half a tablespoon into a small pot, add boiling water, let it dissolve a bit, stir in then add to your watering can or whatever. Added just before flowering begins this definitely ads to the weight of the buds.

Another option is to soak a tablespoon of bat guano in 5 litres of hot (not boiling) water over night, mixing well, and using the next day. Feeding every couple of weeks is normally sufficient.

Super Soil Options

I saved a copy here of the super soil recipe from legendary outdoor grower Tom Hill if you want to really go for it.

Getting hold of the ingredients for ‘Super Soil’ can be difficult, however, I recently discovered a company that supplies everything you need to make the best ever soil for cannabis plants.

In the UK there is a company called ‘Living Soil’ who make amazing dry soil amendments.

They even have specific amendments for autoflowering plants. If you are in the US or Canada there is an alternative called Gaia Green.

If you are serious about growing organic cannabis I cannot recommend enough using Living Soil amendments along with any sort of ‘light mix’ soil. They work best when left to ‘cook’ for a couple of weeks.

When using bottled fertilisers always use much smaller measures than suggested by the fertiliser manufacturer. Often following manufacturers instructions leads to over feeding and burning.

Do be very careful it’s an easy mistake to make. It may be better at first not to use any fertilisers as it’s so easy to cock it up – especially if you are using a soil with food already in it. Fish Mix is another great all round fertiliser that feeds the plant and is difficult to over use.

You can start plants indoors under a fluorescent lamp (like a kitchen tube) for 24 hours a day without a problem. You’ll have to put them up close (like an inch or so) for that type of light to work ok. They are cool so don’t burn the plants.  These types of light are fine for the early stages of growth.

You can still start plants outdoors when it is not April. You could plant something in say August  and all that would happen is that it would go straight into flower if there is enough darkness. In effect seeds planted when we have long nights (12 hours dark or more) will ‘autoflower’ and should be fine as long as they don’t get too cold. Less than 15 degrees seems to be when they will start to become unhappy. You can protect plants from the cold with cloches, cold frames, a greenhouse or by bringing them inside for cold nights.

Growing out of season yields are obviously not as big as normal, but certainly can be larger than some autoflowering plants. For many people the smaller size of plants grown like this can also be an advantage. Remember you can also ‘tie down’ plants that are getting too big, or ‘top’ them to keep them under a certain height. This normally leads to higher yields.

Autoflowering plants are becoming popular in the UK, with the possibility of two grow seasons in one summer – I would start planting these in May, June and July.

There is a new class of Autos known as ‘Super Autos’. ‘Chaze‘ is particularly good as an outdoor plant in the UK that yields significantly more than your normal  auto though takes a bit longer then 70 days.  Magnums are also amazing for yield and high.  Autoflowering plants can also be topped but some handle it better than others.  You can keep an autoflower successfully under 24 hour light – many people have – so if the weather is crap you could bring an auto inside at night for more light if you have a decent light.

The water that you use to water your plants is hugely important, particularly if you are growing in pots. In the earth this tends to be less of an issue. Some people PH their water, some don’t. I did for a while and then noticed the plants seemed to love the rainwater which was around 8 as well – the same as tap.

Tap water in the UK contains calcium and other elements that can be good for weed. Outdoors you should be OK without messing around with this too much but if you notice discolouration on your plants it may be worth checking the ph of your water – Around 6 is good.

Autoflowers worthy of mention

Since I first wrote this article, more autoflowering strains have come out, and I have discovered others which I must include:

Maxi Haze – These plants are very high yielding outdoors, up to 200g per plant. From Grassomatic, an expert Spanish company. Well worth a look.

Frisian Dew Auto – This is Dutch Passion’s autoflowering version of their very best outdoor plant. Ideal for the UK climate.

Super Skunk Automatic – The classic from Sensi in autoflowering format.

Magnum Autoflowering is a kick arse autoflowering variety. The highest yielding auto I have personally grown. Given plenty of room this plant really delivers. Reports of 250g+ if grown in the ground. The smoke is really nice – an upbeat, euphoric high that lasts as well as any photoperiod variety. Highly recommended.

Jack 47 Auto – this plant literally explodes. Difficult to get less than 2 oz per plant I have found. High is good though I do prefer Magnum overall. This is also now available in an XL form.

Girl Scout Cookies – amazing auto with US genetics from Fast Buds that yields very well.

Cream Mandarine from Sweet Seeds – having some amazing results with this plants, in the last grow outdoors was able to yield over 50g from one of these beauties. Strong, long lasting high also.

4.3/5 - (3 votes)

22 thoughts on “Can I grow cannabis outdoors in the UK?”

  1. I’m growing PJs and they’ve sucked so far. Really bad genetics in the batch of seeds I got. Out of 10 seeds, only 3 have made it past the seedling stage and today the first of them showed sex – male! So all my hopes are pinned on the remaining two, which are now growing quite nicely on my patio (I move them to mini greenhouse overnight). A lot of the seedlings grew weirdly in one way or another but click here to see the strangest one:

    Love the blog, by the way.

  2. i found 3 seeds in my bag of herb, planted and all 3 grew !! my son knocked 1 over and it died 🙁 the other 2 are now growing in the garden, and looking better by the day ! i smoke a fair bit of hydro grown stuff, im looking forward to the o’natural when it finally buds 😉 i’ll keep you informed. Love the blog also 🙂

    First time grower

  3. Hi I have done the same thing and I am a first timer, how are yrs coming along and wot will you do with them when it starts to get cold?? I’m not sure how and when mine will flower they are about 350mm tall and have 7 blades on them

  4. Bring them in at night when then the low drops below around 10 degrees. If you bring them in to a lit area you’ll be able to control when they flower. They need 12 hours of complete darkness to flower – if you ensure they are only getting 10 then they wont flower, they will just keep growing until you change the light. If you don’t do any of this they should start flowering once they’re big enough to – and that point is different for each plant.

  5. So a quick update I flowered one of my plants by putting a bin over it to keep it dark so it’s getting 12/12 and it seems to be flowering quite nicely and the rest I have just left in the garden and have started flowering naturally that all seem to be coming on ok I just hope the weather stays ok and I can harvest before the frost comes this garden growing would be a lot easier out of the uk but more of an experiment this yr to see wot happens

  6. the 12 hours rule is a general guide that covers all strains so that given 12 hours of darkness any strain will flower no matter what part of the globe it originated 
    many indica strains only need 9.5 to 10 hours of darkness to reach the critical darkness point and trigger flowering 🙂 

  7. when can i plant my passion 1 outside in the uk please and when can i plant my white berry outside ??? any advice would be great thanks

  8. Not yet! I’d wait until the low is steadily above 9 or 10 degrees (a min/max thermometer is useful for this). And when they go out just a bit at a time each day is recommended so they can adjust properly.

  9. Hi cant tell you how glad i am to come across your piece above on outdoor growing, I have spent the last year trying to digest indoor growing just from bits here and there in different books. Indoor growing is great , nothing better than producing enough to keep you going for the next year in a three months , but with the hazzards of light heat/increase low energy usage/ odour control ya tend to spend the whole process with cross fingers. odour and lighting heat is ya major risk of gettin ya collar felt.

    Also with energy costs rising and the equiptment needed for indoor growing it still costs ya a few quid to run a complete process.

    Ive ordered the dutch passion , I dont wanna use soil, in the process of my research i come up with my own design of oxypot 6 pot system , which i now works absolutly amazing, that much so that im selling these kits i produce myself .

    Do you see any problems in me using this system outdoors that will have affect on the sucess of the plants,   and when do you suggest i put them out side, is there a paticular month or is it just when temp is above 9 degrees ? and i take it im best to get these as big as i can, is that on  continuous light untill outside growing day comences ?? or contoled reduction of timed light slowly braught down to the hours  daylight hours when there starting their outside growing

    And finally have you heard of size and yield increase from heat controled oxypot nutrient feeding  ?? , and also  the understanding that roots are lets say the  nerve centre of the plant, and thats where the growing can be manipulated  im thinking if im using the oxypot system outdoors with a heated oxygenated nutrient water tank would the plant above the roots be able to handle being out in cooler temperatures than 9deg

    Thankz .

  10. I’m afraid I can’t answer individual growing questions, I will probably be wrong and it will take up too much time. Will update articles as I learn more. You could try the forums there are plenty of professional UK growers there with a lot more experience than me

  11. Why does no one ever give a good time to first put your plants out? but only the flowering dates? seriously its crazy hard to find some one stating a good time to start going outside. That would go rele well in this little guide .

  12. Wow! this is such a great news that we can grow cannabis in outside of the UK. These are some valuable tips for growing cannabis in a better way. I am going to apply all these techniques for growing cannabis in my garden.

  13. i am germinating 5 seed as wee speak and i was wondering if i planted them outside howlong will it take them to grow and can they grow at this time of year as its nippy out side

  14. I got 2 bubba kush plants in my polytunnel in my garden they are now starting to smell strong 3 ft tall and looks like starting to flower, how can I contain the smell

  15. Hi guys… I need help… My partner was growing2 plants in the kitchen he then got sent to prison. Not know what to do with them as they got bigger I planted them in big pots out in my garden with my peas and
    My issue is there now about 4 foot tall and starting to Bud I think…. But I have no idea. I can’t ask him cos he is locked up. Please can someone tell me if there is anywhere I can sell the whole plant as I don’t want to kill it. But I don’t know what to do.

  16. Nice write up mate! Quick question… What kind of pots would you recommend for outdoor growing in the UK? I have some large clay pots, but have read It’s best to go with fabric one. Cheers!

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