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Autoflower Marijuana Seeds for Sale in Canada

Autoflowering seeds begin flowering on their own after about three to four weeks, whatever the light does. They are the fastest, most forgiving way to grow cannabis in Canada.

Autoflower marijuana seeds are cannabis seeds that begin flowering automatically after about 3 to 4 weeks, regardless of the light schedule. They carry Cannabis ruderalis genetics from northern climates, finish in 8 to 10 weeks from sprouting, and usually stay between 60 and 100 cm tall, which makes them the fastest option for Canada’s short outdoor season.

Last updated: July 2026

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Autoflowers move from seed to harvest on their own schedule, usually in eight to ten weeks.

How autoflowering seeds work

Standard cannabis is photoperiod dependent: it only begins flowering when daily light drops toward twelve hours. Autoflowers carry genetics from Cannabis ruderalis, a subspecies from harsh northern climates that evolved to flower on age rather than light. Your plant simply starts budding when it is ready.

Seed to harvest in 8 to 10 weeks

You never change a lighting schedule and never risk stunting a plant by mistiming the switch. Outdoors that means planting in June and harvesting in August, well before frost, and in many regions running two crops in one summer.

Built for Canadian conditions

  • Short seasons. Prairie and northern growers harvest before first frost instead of racing it.
  • Cool nights. Ruderalis genetics tolerate temperature swings better than most photoperiod plants.
  • Discretion. Most stay 60 to 100 cm, easy to keep below a fence line or inside a small tent.
  • Speed over size. Yields per plant are smaller, but you harvest sooner and more often.

Growing tips specific to autoflowers

Autoflowers do not wait for you, so a lost week is a lost week. Plant directly into the final container to avoid transplant shock, feed lightly, and avoid heavy training such as topping. Low stress training, where you gently tie branches outward, is the safer way to open the canopy. Keep them under 18 to 20 hours of light indoors throughout.

Who should grow them

They suit first-time growers, anyone short on space, and experienced growers wanting a quick harvest between photoperiod runs. To maximise yield per plant instead, see our feminized seeds; for a calm, low-THC harvest see auto CBD seeds.

Every MJ Seeds Canada order includes: a germination guarantee, plain discreet packaging with no cannabis branding, and 3 to 7 day delivery from Vancouver, BC to every province and territory. Pay by credit card, Interac e-Transfer or Bitcoin, with free shipping over $200.

How autoflower marijuana seeds compare with other seed types

Seed typeStarts floweringSeed to harvestPlants producedBest for
FeminizedLight cycle (12/12)9 to 16 weeks totalFemale onlyBiggest yields per plant
AutoflowerAge, about 3 to 4 weeks8 to 10 weeks totalFemale onlySpeed and short seasons
RegularLight cycle (12/12)9 to 16 weeks totalMale and femaleBreeding and mother plants
High CBDDepends on variety9 to 14 weeks totalFemale onlyLow THC, clear-headed
Fast VersionLight cycle (12/12)8 to 12 weeks totalFemale onlyFull yield, earlier finish
Auto CBDAge, about 3 to 4 weeks8 to 10 weeks totalFemale onlyEasiest low-THC grow

Times shown are typical ranges from seed to harvest and vary with strain, climate and setup.

Autoflower marijuana seeds: frequently asked questions

How long do autoflower seeds take to grow?

Most autoflowers go from sprout to harvest in 8 to 10 weeks. Because flowering is triggered by the plant’s age rather than the light cycle, that timeline stays fairly predictable whether you grow indoors or outdoors.

Do autoflowers need a special light schedule?

No. Autoflowers flower on their own, so most growers simply leave the lights on 18 to 20 hours a day for the entire cycle. There is no switch to 12/12 and no risk of stunting a plant by changing the schedule at the wrong time.

Can you grow two autoflower crops in one Canadian summer?

In many regions, yes. Because autoflowers finish in about two months, growers who plant in late May or early June can harvest in August and run a second crop that finishes before the first frost, depending on local climate.

Do autoflowers yield less than photoperiod plants?

Per plant, usually yes, because autoflowers stay smaller and have a fixed vegetative window. Growers offset this by harvesting sooner and more often, and by growing several compact plants rather than a few large ones.

Should beginners start with autoflower seeds?

Autoflowers are one of the most forgiving starting points because there is no light-cycle management and no males to remove. The main rule is to plant directly into the final container and avoid heavy training such as topping, since the plant cannot wait to recover.

Are autoflower seeds feminized?

The autoflower seeds sold by MJ Seeds Canada are feminized, so they produce female, bud-producing plants. Autoflowering and feminized describe two different traits: one is about what triggers flowering, the other about the plant’s sex.