Big Devil XL Auto

Big Devil XL Auto Cannabis Seeds by Sweet Seeds

Big Devil XL Auto is a feminised autoflowering cannabis seed that delivers genuinely massive yields from a plant that grows taller than most autos have any right to. Sweet Seeds crossed Big Devil #2 with Jack Herer Auto and ended up with something that reaches 100–160 cm, branches heavily, and still finishes in roughly 9½ weeks from seed. If you've been disappointed by the output of compact autoflowers, this is the strain that changes the conversation.

Why Big Devil XL Auto Seeds Stand Out

Most autoflowering strains top out around 60–80 cm and produce modest harvests. Big Devil XL Auto throws that rulebook out. At 100–160 cm, it's closer in stature to a photoperiod plant, and the yields reflect that — up to 650 g/m² indoors and up to 350 g per plant outdoors. Those numbers put it in a different league from the compact autos that dominate the market.

The genetics behind it tell the story. Big Devil #2 brings the bulk — that line was already known for pushing autoflower size limits. Jack Herer Auto contributes resin production and an intense, well-rounded effect. The combination produces thick, dense buds absolutely loaded with trichomes. When you crack open a cured jar, the aroma is rich and layered — sweet, slightly spicy, with enough presence that you'll notice it across the room. This isn't a subtle strain.

One honest limitation: this plant branches a lot and gets tall. That's brilliant for yield, but it means Big Devil XL Auto is not your best pick for guerrilla growing. It'll tower over surrounding vegetation and draw attention. If stealth is the priority, look at something more compact like Sweet Seeds' Dark Devil Auto, which stays shorter and carries darker foliage. But if you've got a proper indoor setup or a private outdoor spot, Big Devil XL Auto rewards you like few other autos can.

Big Devil XL Auto Grow Specifications

Growing Big Devil XL Auto Seeds — Indoor and Outdoor

Big Devil XL Auto works well both indoors and outdoors, which is part of its appeal. Indoors, give it a decent-sized pot — at least 15–20 litres — because the root system needs room to support all that vertical growth and branching. With a proper light cycle (most growers run 18/6 or 20/4 for autos), you'll see the plant stretch noticeably in the first few weeks before flowering kicks in automatically.

Outdoors, this strain thrives in warm, sunny climates but handles cooler northern European summers reasonably well thanks to the fast finishing time. The 9½-week total cycle means you can germinate in late spring and harvest before autumn weather turns ugly. Just remember: at up to 160 cm with heavy branching, it's not exactly inconspicuous. A balcony surrounded by taller buildings works. An open allotment where the neighbours can see? Less ideal.

One thing we've noticed with tall, heavy-yielding autos: the branches can get weighty in late flower. A few bamboo stakes or plant yo-yos will save you from snapped branches when those dense buds pack on their final weight. It's a small investment that prevents a genuinely annoying loss.

1. Germinate seeds using the paper towel method or directly in a small pot of moist, light soil mix.
2. Transplant seedlings into their final container (15–20 litres minimum) within the first week — autoflowers don't love being repotted once they're established.
3. Provide 18–20 hours of light per day indoors. Outdoors, place in the sunniest spot available.
4. Feed lightly during the vegetative stage and increase nutrients gradually as flowering begins. Autoflowers are sensitive to overfeeding — half-strength nutrients are a safe starting point.
5. Support heavy branches with stakes or ties during the final 2–3 weeks of flowering.
6. Harvest when trichomes show a mix of milky white and amber under magnification — typically around 9½ weeks from germination.
7. Dry in a dark, ventilated space at 18–22°C for 7–10 days, then cure in airtight jars for at least 2 weeks for the best aroma and smoothness.

Big Devil XL Auto vs Other Autoflowering Strains

To put Big Devil XL Auto in context, here's how it stacks up against two other popular autoflowering strains in terms of the numbers that actually matter.

The yield difference is significant. Big Devil XL Auto pushes up to 650 g/m² — roughly 30–45% more than many competing autos. The trade-off is height and visibility. If you're growing in a 60x60 cm tent with limited vertical clearance, you might find this plant bumping into your lights. An 80x80 or larger tent with at least 160 cm of usable height is what we'd recommend. If your space is tight, Dark Devil Auto from the same breeder stays much more compact and still delivers solid results.

What the Buds Are Like

The cured buds from Big Devil XL Auto are thick and dense — properly chunky, not the airy popcorn nugs you sometimes get from autoflowers. The resin coverage is heavy, which is the Jack Herer genetics making themselves known. When you break a bud open, the trichome layer is visible without a loupe.

The aroma is where this strain really earns its reputation. It's a rich, sweet scent with spicy undertones — not one-dimensional at all. In a jar, it fills the room the moment you crack the lid. The effect is described by Sweet Seeds as intense, and the resin density backs that up. Dry eyes and dry mouth are commonly reported side effects, so keep water nearby.