One of the best ways of growing cannabis, especially for beginners, is to grow outdoors. Growing cannabis outdoors can be very easy and very rewarding, but this is very dependant on which strain you’re growing. Understanding which strain is best suited to your particular climate is the difference between growing, big chunky ripe cannabis plants and losing an entire crop to autumn weather. Using a strain that doesn’t suit your climate often means you’re growing something that will never have the chance to fully mature and will produce light, airy flowers at best.
When deciding which Spliff Seeds strain of cannabis seeds to grow outdoors, you must first consider two main conditions: location and season. The main component of the “location” part is to consider how far away the equator is. A number of our varieties of cannabis seeds is far better suited for growers that live at a higher latitude than others, especially in the northern hemisphere. How far north or south you are will cause differences in temperatures, season length and quality of light among other things. Those who are fortunate enough to live in the (sub)tropical conditions closer to the equator have much more options.
Autoflowering varieties do not follow the regular season, which makes them very practical for growing cannabis outdoors. Make sure you also check out our background article on autoflower seeds and our step-by-step guide on growing them.
Semi-autoflowering varieties have autoflowering characteristics that we won’t get into here, but they are essentially extremely fast-flowering outdoor strains. Because growing cannabis outdoors is tricky in large parts of Northern Europe, autoflowering and semi-autoflowering varieties are very popular in this region. In Southern Europe autoflowering strains are also gaining popularity as a way to get an early harvest in before the “main” harvest is done.
Autoflowering cannabis plants will produce 20g - 60g of high grade flowers per plant. This may not be a huge amount, but you can technically be growing cannabis year round to make up for it. The Spliff Seeds selection of autoflowering cannabis seeds consists of Dutch coffeeshop classics: AK Automatic, Dutch Blue Automatic, Dutch Automatic, Medical Kush Automatic, Spliff Cheese Automatic and White Widow Automatic.
Semi-autoflowering varieties are more like photoperiod strains in that they do have a vegetative period and rely on the season to start flowering. They start flowering much earlier than normal varieties, we’ve seen buds develop over a month earlier than what we’re used to from photoperiod strains. Our fastest semi-autoflowering strain, Gold Rush Outdoor, finishes as early as the beginning of September. These strains are among our most productive outdoor varieties and can yield over 400 grams per plant quite easily, but more importantly they are suitable for virtually any climate. Our semi-autoflowering varieties include: Fast Bud Outdoor, Gold Rush Outdoor and Sweet ‘N Sour Outdoor.
Spliff Seeds is an Amsterdam based company, so we have a lot of experience with growing cannabis in the challenging weather this part of Europe is known for. Daytime temperatures during summer months can reach up to 20-30 °C, while winter temperatures can be as low as minus 16 °C.
Summers are also relatively short in the Netherlands, which means our outdoor season for growing cannabis also ends earlier than in many other countries. The “classic” outdoor season starts in may because this is usually when nighttime temperatures start to remain above 10 °C. Under normal circumstances it is advisable to harvest before mid october, when autumn really starts to set in.
Growing cannabis outdoors in this region means you should consider strains that finish their flowering period as early as possible, but no later than mid-october. Another thing to look at is how resistant a strain is to changing weather conditions, with a focus on high humidity and low temperatures during flower.
Aside from the autoflowering and semi-autoflowering varieties, we have a wide selection of photoperiod strains for outdoor cannabis cultivation. Our favourite photoperiod strains for growing cannabis outdoors in the Netherlands include: Afghani Gold, AK, Blue Medi Kush, Blueberry, Bubblegun, Crystal White, Medical Kush, Power Plant, Snow White and White Widow. All of these varieties are available in our webshop as feminized cannabis seeds.
This list is mostly built up out of indica strains, or indica/sativa hybrids that show a lot of indica characteristics in terms of growing. The growth pattern of these strains is quite similar in that they usually grow to a medium height, with multiple stronger side branches producing buds from top to bottom.
In colder climates growers should work with cannabis seeds with shorter flowering times to ensure their plants have the time to develop big thick flower sets and fully mature. The majority of the cannabis seeds listed above finish flowering in September, which is ideal for Northern Europe.
Cold and wet weather towards the end of the season are yearly problems for growers in Northern Europe, which often makes growing cannabis go hand in hand with bud rot and powdery mildew. A large part of these problems can be avoided by simply growing a variety of cannabis seeds that is very resistant to such threats.
Your biggest concern when growing cannabis in this part of Europe will be the cold and wet weather. For this reason the Netherlands has always been a driving force in greenhouse agriculture/horticulture and has a huge agricultural export, despite the limited space and weather conditions. Just to name a few numbers, the Netherlands is the number one exporter of seeds, flowers, plants and bulbs and the second largest exporter of fresh vegetables worldwide. Greenhouses work extremely well in the Netherlands, growing cannabis is obviously no exception!
A simple and cheap way to build a greenhouse to shelter your plants from the rain and wind is using home made polytunnels. Polytunnels are the long, caterpillar shaped plastic tunnels that you see in many agricultural settings. These plastic greenhouses are also great for keeping the outdoor garden secured from neighbours and helicopters, whilst costing very little money and time to build. Tunnel-shaped greenhouses work well in almost any outdoor environment and are easy to use. A simple layer of thin plastic can reduce wind-cooling by 50%. Make sure that your polytunnel is placed from North to South, this way your plants will receive as much sunlight as possible.
Polytunnels can be used when growing in the ground or using pots, which both have their pros and cons. If you choose to use pots it is good idea to use felt pots. These will not only keep the grow medium warmer but they will also promote better root development, leading to bigger and stronger plants and final buds. For more information on growing cannabis with the best root system possible, make sure to also check out our article on air pruning.
Using polytunnels also makes light deprivation strategies much easier, this technique is used to force early flowering in photoperiod strains. Make sure to read our article about light deprivation for more information on this subject!
Growing cannabis in polytunnels will shelter your plants from the worst weather, but still adheres to the same rules in that you should grow fast flowering strains. Stick with (semi-)autoflowering- and Indica dominant strains when growing cannabis outdoors in Northern parts of the Northern hemisphere for optimal biomass and the largest harvest. For optimal grams per square meter it is often best to use a small sea of green setup.
Living in Southern Europe allows a grower to grow Indica or Sativa cannabis seeds with excellent results. The weather is much different in Southern Europe, with daytime temperatures in the summer of 25-40 degrees and nighttime temperatures of 20-25 degrees. The season is also much longer, which allows for growing cannabis varieties with much longer flowering periods. The longer season also gives you more options in terms of training plants, as you potentially have a few extra months of veg time. All of the cannabis seeds that we suggest for Northern Europe will perform even better in Southern Europe, but the amazing weather there will also allow you to grow varieties that were originally developed for indoor cannabis cultivation. Our new Kush lines are a good example of indoor strains that turned out to do amazingly well outdoors in southern Spain.
These sativa dominant or hybrid strains will produce excellent results, but grow differently than the Indica dominant strains we mentioned earlier. The main difference lies in the flowering time: sativa dominant strains ripen after 12-14 weeks of flowering in consistently warm weather. Sativa strains are usually tropical varieties that grow much taller and faster than indica varieties, sativa strains have been known to grow upto 4 metres tall! The cannabis seeds listed here prefer at least 9 weeks of consistent undisturbed strong sunshine during flowering. Expect these strains to want to grow tall and express their genetic heritage with huge tall thick buds.
Southern European problems are quite opposite to what we described for Northern Europe in that most issues with growing cannabis in Southern Europe are caused by the extremely high temperatures. In areas where summer temperatures can easily rise above 40 degrees, growers have to be extra vigilant to insects, heat damage, dehydration issues and plant stress.
Growing cannabis seeds in Southern Europe means you can grow huge plants in close to tropical weather. Your biggest problems with growing cannabis in these regions will be heat and insects. A good way to ensure that the plants are always happy is to add a saucer under the plant to act as a bottom feeding reservoir. This way the plant will have a buffer so that it can always drink what it needs, in case you cannot stay on top of the rate your plant uses nutrients and water.
We’re fans of polytunnels in hot climates too, in this case they provide shelter against sunlight and heat, rather than cold wind and rain. Polytunnels are very popular in commercial agriculture in Southern Europe because this allows growers to save water and prevent plant stress.
Staking plants with bamboo cane is also very helpful considering some of the outdoor varieties can grow over 4 metres in height. Making a large trellis early on to support the plant's structure is always a good idea, otherwise plants might fall over due to their own weight later down the line.
If you want to keep your plants a bit smaller you can also plant sativa strains later in the season to shorten their vegetative period. While 4 meter plants are definitely a possibility when starting in April or May, starting halfway through June will keep your plants significantly smaller.
Growing both indica and sativa varieties will allow you to harvest indica dominant plants around 3 weeks earlier than the sativas. This is always a good option if you want to have some serious variety in your selection of cannabis strains and extracts.
Depending on which part of Europe you live, growing cannabis might be possible year round. Cannabis seeds can be planted as long as the temperatures allow for it, regardless of the season. In the “offseason” however, the hours of light per day will often force flowering as soon as possible, which limits the yield per plant by a lot. You can work around this by planting more cannabis seeds in a sea of green fashion.
Planting cannabis seeds between July and October will reward you with ~1 metre tall plants that yield 20-50 grams per plant. These shorter plants have the advantage that they are harder to spot than taller plants that have been growing all season. Growing cannabis like this essentially mimics the way autoflowering varieties work, as seedlings will start flowering as soon as possible.
An added little bonus of growing cannabis outdoors is that every other grower in your region will be subjected to the same weather conditions as you, making comparing plants a lot of fun. Can you grow better buds than your friends?
Whichever variety of cannabis seeds you decide to grow, we hope this article has given you an idea of what your best options are. At Spliff Seeds we’re big fans of growing cannabis outdoors and still get excited about the outdoor season every year. Growing cannabis outdoors is a great way to get some free marijuana in a cheap and easy way. And if you’ve got the right genetics, producing high grade buds shouldn’t be a problem at all. Have fun growing cannabis this season, we know we will!