Cannabis seeds for the UK

Growing cannabis outdoors in the UK (climates guide)

The UK has a temperate oceanic climate, occupying mid-Atlantic latitudes from 49° to 61°N in western Europe. The close path of the jet stream ensures that the weather is changeable. The average annual rainfall is around 1.4 metres with around 130 rainy days each year. On the other hand, there are around 1500 hours of sun per year across the UK, that's around 4 hours per day on average.

The growing season for outdoor cannabis in the UK varies significantly across regions, and understanding the local climate is crucial for success. From January to February, growers focus on scouting potential grow locations, while also preparing the soil for future planting. March and April see preparations intensify, with growers getting ready to plant outdoors once the risk of frost has passed, usually in May. During this time, cannabis seeds may be germinated indoors to give them a head start, with the goal of transferring them outdoors once the weather stabilizes.

By May, many growers are planting their seedlings outside, especially in the warmer southern regions, though some may still use greenhouses or poly-tunnels to protect their plants. June and July bring the promise of longer days and more stable weather, with plants growing rapidly. However, pests such as slugs and snails are common, and growers often have to protect their crops with barriers or organic solutions. For those growing autoflowers, harvests may start in July, while photoperiod strains continue to develop.

As the season progresses into late summer and autumn, the weather becomes more unpredictable. August and September are key months for nurturing plants, with some autoflower varieties ready for harvest by August. However, the threat of mold and bad weather looms, particularly in the northern regions. October often marks the end of the growing season, though some southern growers may still manage to harvest a final crop. By November, growers are tidying up their plots and preparing for the next season.

Best outdoor cannabis seeds to grow in the UK

UK growers have two main options: autoflowering seeds and photoperiod feminised cannabis seeds. Fast Feminised seed varieties, specifically Think Fast gives excellent results finishing bloom in September. That's around a month earlier than typical outdoor photoperiod feminised seed varieties.

Both autoflower and feminised seed varieties can thrive in the UK climate, but Dutch Passion only recommend a selection of photoperiod strains due to the unpredictable late-season (September/October) UK weather, especially in the north.

The UK’s autumn weather can be particularly challenging as temperatures drop, wind/rain arrives in force and the days get shorter. Careful strain selection is key to a successful harvest, with many growers (especially those in the north) opting to include autoflower seed varieties and Fast Feminised strains just in case their outdoor photoperiod feminised strains struggle with late-season weather.

Best cannabis seeds for the South Eastern climate

The South Eastern part of the UK can have cold, sharp winters, But summers can be sunny, dry and pleasant with plenty of warmth. Sometimes warm air masses from continental Europe can keep summers dry with occasional heat waves and 30ºC temperatures. Summers can also be grey and cool! South-east UK encompasses Norwich, Cambridge, Portsmouth and of course London. Growers in the South East find it possible to grow a wider range of feminised seeds than growers in Northern England.

• Auto Cinderella Jack
• Shaman
• Auto Euforia
• Think Fast
• Frisian Dew

Best cannabis seeds for the South Western climate

The South Western area of the UK often sees mild but wet winters. Summers are often warm but with plenty of Atlantic weather blowing in cloud and rain. The mild conditions allow a longer growing season than is possible in more northern regions. The South West includes South Wales, Cardiff, Exeter, Cornwall, Plymouth, Southern Wales etc. Just like South-East UK, growers in the South West will also find it possible to grow a wider range of later-finishing outdoor feminised strains than growers in northern England or Scotland.

• Auto Euforia
• Passion #1
• Auto Ultimate
• Think Fast
• Shaman

Best cannabis seeds for the North-West climate

Cannabis growers in the north-west experience cool winters and summers which tend to be colder and greyer than those further south. Prevailing Atlantic winds can bring rain and wind pretty much all year round. The North-Western region includes areas such as Northern Ireland, Northern Wales, and Western Scotland as well as areas like Greater Manchester, Merseyside etc. Growers in this region may find late season weather in September and October less friendly for growing slower-blooming outdoor strains. Growers need to be selective about buying feminised outdoor strains but will get good results with autoflower seeds.

• Think Fast
• Auto Blueberry
• Auto Lemon Kix
• Frisian Duck
• Auto Daiquiri Lime

Autoflower vs feminised cannabis seeds growing in the UK

Cannabis seeds suited for the UK climate need to finish within the short growing season. One of the biggest challenges for UK growers is selecting strains that will mature in time. For those cultivating cannabis outdoors, there are two main options: autoflower seeds and photoperiod feminised seeds.

Autoflower seeds have a quicker growth cycle and tend to stay shorter, typically reaching around 1 meter in height. However, the faster lifecycle of autoflowers usually means a lower yield compared to photoperiod feminised strains. This is a natural trade-off for their rapid development.

On the other hand, photoperiod feminised seeds usually take 5-6 months to complete their outdoor growth cycle. This means that, depending on the start time, harvest may coincide with the unpredictable October weather. However, these strains often produce larger plants and bigger yields compared to autoflowers.

Regardless of the type of seed, many UK growers choose to germinate their cannabis seeds indoors and keep the seedlings under artificial light (typically 18-20 hours per day) for the first few weeks. This gives the plants the best possible start by protecting them from outdoor weather conditions and pests during their most vulnerable stage of growth. Whether growing autoflower or feminised seeds, this method helps ensure stronger, healthier plants that are better prepared for outdoor life.