Black Rainbow Auto Seeds by Seed Stockers – Fruity Indica-Dominant Autoflower with High THC

Black Rainbow Auto seeds by Seed Stockers deliver a powerful, fast-finishing autoflower that packs high THC, fruity flavors, and massive yields in just 11 weeks—perfect for growers who want quality without the wait.

Struggling with slow, low-yielding autoflowers?

Let’s face it: most autoflowering strains promise big but end up delivering small, airy buds and underwhelming effects. You invest time, space, and effort, only to harvest a few grams of forgettable weed that barely gets you off the couch.

What if your next grow could be faster, tastier, and way more potent?

Imagine skipping the stress of light cycles, avoiding the hassle of training, and still harvesting dense, frosty buds that smell like a mix of grape candy and diesel. That’s exactly what Black Rainbow Auto offers—no compromises, no guesswork, just results.

Black Rainbow Auto: the 11-week powerhouse with flavor that pops

Bred from Watermelon Zkittlez × Bacio Rainbow and crossed with Apollo Black Cherry Auto, this feminized autoflower is a terpene bomb with THC levels up to 26%. It grows up to 1.00 m (3.28 ft) tall, produces up to 450 g/m² (1.59 oz/ft²) indoors, and thrives in both soil and coco. Whether you're in a grow tent or on a balcony, this strain adapts fast and delivers hard.

How Black Rainbow Auto maximizes your yield and flavor

This strain isn’t just fast—it’s smart. Its compact, bushy structure and wide internodal spacing make it perfect for dense planting or Sea of Green setups. The buds pack trichomes like golf balls in glitter, and thanks to its resistance to mold and pests, you won’t lose your harvest to botrytis even in humid conditions.

• Because it’s autoflowering, you can harvest up to 4 times a year—no light timers needed
• Thanks to its high myrcene and caryophyllene content, you get a deeply relaxing effect with a burst of fruity euphoria
• With dense, compact buds, you get more usable flower per gram and less waste during trimming
• Since it resists stress and temperature swings, you can grow it outdoors in Mediterranean or temperate climates without fear
• As a feminized strain, you get nearly 100% female plants—no wasted space on males

Simple setup, big results: how to grow Black Rainbow Auto

Start with a 20 L (7.06 gal) pot from day one to avoid transplant stress. Use a well-aerated mix like Coco Mix 50L for better drainage and root development. Keep light at 18/6 or 20/4 throughout the cycle, and maintain temperatures between 22–26 °C (71.6–78.8 °F) in veg and 20–25 °C (68–77 °F) in flower.

1. Germinate seeds in a moist paper towel or directly in the final pot
2. Provide 18–20 hours of light daily—no need to switch schedules
3. Water when the top inch of soil feels dry; avoid overwatering
4. Feed with a balanced nutrient line like HESI Bloom Complex for Soil during flowering
5. Harvest when 70% of trichomes turn milky-white with some amber hints

Why this strain earns top marks for flavor and effect

Black Rainbow Auto hits with a wave of sweet, grape-like terps backed by spicy diesel and earthy Kush tones. The high starts cerebral—clear-headed and slightly euphoric—then melts into full-body relaxation. It’s perfect for unwinding after work, enhancing music, or sparking creative thoughts without locking you to the couch.

• Because it’s rich in limonene and pinene, you get a mood-lifting start with mental clarity
• Thanks to its indica dominance, you experience deep muscle relaxation and stress relief
• With THC between 20–26%, you get strong effects even with small doses
• Since it has low CBD, it’s not sedative—ideal for evening use without next-day fog
• As it burns clean in joints or vapes smoothly, you enjoy maximum flavor with minimal throat irritation

Pro tips to get the most from your Black Rainbow Auto grow

Don’t top or supercrop—autoflowers hate stress. Instead, use low-stress training (LST) early to open up the canopy. In humid environments, add a small fan and consider using Top Crop Fertilizer Pack Professional to boost resin production and terpene expression. For even better results, flush 7–10 days before harvest to improve taste.

Frequently Asked Questions

How long does Black Rainbow Auto take to grow?

From seed to harvest, it takes about 11 weeks. Indoors, you can start another round immediately for back-to-back grows.

What’s the best climate for growing Black Rainbow Auto?

It thrives in temperate, Mediterranean, and continental climates. It handles heat well but prefers protection from heavy rain during flowering.

Does it need special nutrients?

No—use a standard flowering formula. But avoid overfeeding; autoflowers are sensitive to nutrient burn.

Can I grow it in a small space?

Absolutely. It stays under 1.00 m (3.28 ft) and responds well to LST, making it perfect for stealth grows or micro tents.

Personal Experience of Pevgrow’s CEO (Alan)

I grew Black Rainbow Auto in my 1.20 m (3.94 ft) tent with a 300W LED and got 420 g (14.82 oz) from three plants. What blew me away was the smell—like grape soda dipped in diesel—after just eight weeks. I didn’t train them, just let them go wild, and they formed a perfect canopy. The high was smooth: first a little creative buzz, then deep calm. I’d smoke it at 8 PM and be relaxed but still functional. No paranoia, no couch-lock. If you want a strain that delivers flavor, potency, and ease, this is it. I’ve already ordered more for my next cycle.

Technical specifications

• Breeder / Brand: Seed Stockers
• Type: Autoflowering, feminized
• Dominance: Indica-dominant hybrid
• Genetics: (Watermelon Zkittlez × Bacio Rainbow) × Apollo Black Cherry Auto
• Life cycle: 11 weeks from seed to harvest
• Indoor yield: 400–450 g/m² (1.41–1.59 oz/ft²)
• Outdoor yield: 100–170 g/plant (3.53–6.00 oz/plant)
• Indoor height: 80–100 cm (31.50–39.37 in)
• Outdoor height: 90–110 cm (35.43–43.31 in)
• Difficulty: Low to medium
• Structure: Bushy, wide internodal spacing, strong lateral branching
• Climate suitability: Temperate, Mediterranean, continental, humid
• Resistance: Mold, pests, stress, temperature fluctuations
• Training: Suitable for LST and SCROG; avoid topping or FIM
• Pot size: 18–27 L (6.36–9.54 gal) final pot from the start
• Light cycle: 18–20 hours daily throughout life
• Temperature: 22–26 °C (71.6–78.8 °F) veg, 20–25 °C (68–77 °F) flower
• Humidity: 60–70% seedling, 50–60% veg, 40–50% flower
• pH: 6.0–6.5 (soil), 5.8–6.2 (coco/hydro)
• Smell in grow: Medium to high—carbon filter recommended
• THC: 20–26%
• CBD: Low (approx. 0.5–1%)
• Terpenes: Myrcene, caryophyllene, limonene, pinene
• Flavour: Fruity, grape, spicy, diesel, earthy, sweet Kush
• Effect: Relaxing, soothing, balanced cerebral and body high—ideal for evening use