Why is my outdoor cannabis plant flowering too early? (2024)

If you get your outdoor plants going early in the season, e.g. around March the dark overnight period is still long enough to force photoperiod feminised strains to bloom.

This can be an issue for the growers that were tempted outdoors a little too early in the season (perhaps due to a freak early heat wave). The best option is to ensure that you have a period of artificial light to break the period of overnight darkness.

A security light, or similar, which comes on for just a few minutes will do the job and ensure the plant remains in vegetive growth. With prolonged vegetive growth the plant can grow into a large size, especially if it was started early in the year.

In Europe many that grow at Southern Latitudes (Spain, Italy, Greece etc) will start their outdoor plants as early as February, perhaps with protection from a heated greenhouse/polytunnel (if local conditions are still a little too cold). Using artificial lights on for a small part of the overnight ensures the plants grow in veg mode even though the days have perhaps only 9 hours of light.

Outdoor growers that put their plants out in e.g. May often never see their outdoor plants flower too early. That’s because the number of daylight hours in May is significantly higher than March, making it easy for photoperiod feminised cannabis strains to settle into veg mode with the long summer days.

Even though it may be warm enough to grow cannabis outdoors there may be insufficient light to allow vegetive growth. It’s one of the challenges for those growing in countries where the hot weather arrives slightly before the longer days.

It can also be a challenge for those with heated greenhouses/polytunnels who are keen to start their outdoor cannabis seeds as early as possible. Some strains can have slightly differing responses to the length of the day. One strain may grow in veg mode under a given day length, whereas a different strain may respond with early flowering.

The stress of a sudden change in light cycle can also shock a cannabis plant into early bloom. This could happen, for example, if a plant grown on a 24-hour indoor grow cycle was placed outdoors.

The sudden change in the amount of light hours can be stressful to the plant which may respond by flowering - even if outdoor light hours are more than 12 and the plant might normally be expected to grow in veg mode.

Again, the problem is easily solved by giving the plant extra artificial light during the evening. Perhaps by bringing the plant into a lit garage at night or arranging a security light to occasionally come on and light up the area where the plant resides.

• Early flowering outdoor cannabis strains is a term often used to describe traditional outdoor photoperiod strains that finish earlier than usual. These can be very useful strains, especially if your late-season weather can be bad. ‘Fast’ photoperiod strains with recessive autoflower genetics such as Dutch Passion’s Think Fast finish in September in the northern hemisphere, that’s around a month earlier than many traditional outdoor strains. Perfect if you can't guarantee the autumn/fall weather.

• Those that enjoy growing multiple successive outdoor autoflower harvests find it is a convenient, and fast, way to spread the risk. With 2 or 3 successive autoflower harvests each year, it’s not a disaster if one of those crops fail.

If early flowering issues are something that you have seen before then it makes sense to initially grow your preferred outdoor cannabis seeds in containers, rather than rooting them directly into the ground. With your plant in a container, it is easier to move it to an area that receives additional artificial light to break the long night hours.

Those with indoor grow rooms can simply bring the plant to an indoor grow room. Autoflower plants can't be reverted to vegetative growth, but cannabis plants grown from feminised seeds can be re-vegged. Just put them under 18-24 hours of light.

Those growing in a greenhouse or a patio/back garden may find some security lighting that comes on during the evening (even if only for 30min or so) will be able to break the bloom cycle. You will get heavier yields from an outdoor plant that was restored to veg growth after a premature (and undesired) flirtation with bloom. Some growers report that sativa strains may be easier to re-veg than indicas.

Many of the challenges of outdoor growing can be avoided if the grower is able to buy proven outdoor cannabis seeds. Not only should you have solid, reliable genetics which will behave and grow/bloom predictably. But you should also benefit from professional breeding techniques & natural selection which will ensure in-built genetic resistance to some of the common diseases.

Most importantly of all, professionally bred outdoor cannabis seeds will have what it takes to cope with variable weather and cool/grey conditions.

An outdoor grow will often be around a 5-6 month process, so it makes sense to invest time in research before you buy cannabis seeds. If you need some extra inspiration from those that have already grown Dutch Passion outdoor seeds then please check out the hundreds of grow reviews in theDutch Passion blog site where you will find all the grow archives.