LSD-25 Auto
Cannabis seeds
by Fast Buds
LSD-25 Auto Cannabis Seeds by FastBuds
LSD-25 Auto is an autoflowering Indica-dominant cannabis seed that delivers a potent, resinous harvest in just 8–9 weeks from germination. FastBuds crossed the legendary L.S.D. — itself a hybrid of Mazar-i-Sharif and Skunk #1 — with a hardy Canadian Ruderalis to create a compact, low-maintenance plant that punches well above its weight class. At 19% THC and 1.1% CBD, this is one of the stronger autoflowers you'll find on the market.
This product is intended for adults aged 18 and over.
Pack Sizes
LSD-25 Auto seeds come in packs of 3, 5, or 10. If you're running a single tent and want to test the genetics first, the 3-pack is your friend. Going for a full Sea of Green setup or want to pheno-hunt a bit? Grab the 10-pack — you'll get more consistent results across the canopy and better value per seed.
Why LSD-25 Auto Seeds Deserve a Spot in Your Grow Room
The original L.S.D. strain built its reputation on heavy resin production and a deeply relaxing body effect paired with a clear-headed uplift. FastBuds took those genetics and made them accessible to growers who don't want to mess about with light schedules or wait four months for a harvest. The result is a plant that stays between 70 and 120 cm tall, finishes in roughly two months, and still manages to produce 450–500 g/m² indoors. That's a serious yield for an autoflower.
We'd pick LSD-25 Auto over most other auto Indicas in this price range for one reason: the cannabinoid profile. At 19% THC, it sits comfortably above the 15–17% you typically see from autoflowering varieties. The 1.1% CBD adds a secondary cannabinoid layer — CBD is the non-intoxicating compound associated with physical relaxation and is thought to modulate the overall effect of THC. That combination tends to produce a more rounded experience than a pure THC strain.
The one honest limitation: outdoor yields vary dramatically depending on your climate. FastBuds lists 50–250 g per plant outdoors — that's a wide range. In a Dutch or British summer, you're probably looking at the lower end unless you get a genuinely sunny spell. The short lifecycle does mean you can squeeze in a late-season grow that most photoperiod strains wouldn't survive, which is a genuine advantage in northern Europe.
Aroma and Flavour Profile of LSD-25 Auto
Crack open a cured jar of LSD-25 Auto and you'll get hit with an earthy, almost loamy base note — like damp forest floor after rain. Underneath that sits a sweet, musky layer that becomes more pronounced once you break the buds apart. The trichome coverage on mature flowers is dense and sticky; your fingers will need a wash after trimming. When smoked or vaporised, the sweetness comes forward and lingers on the palate. It's not a fruity strain by any stretch — this is old-school Indica character through and through, closer to a classic Afghan hash scent than anything modern and candy-like.
Growing LSD-25 Auto Seeds
FastBuds designed this strain for minimal fuss. As an autoflowering variety, LSD-25 Auto transitions from vegetative growth to flowering on its own internal clock — no need to switch your light cycle to 12/12. Most growers run 18/6 or 20/4 from seed to harvest and see excellent results.
- Germinate your LSD-25 Auto seeds using the paper towel method or directly in a small pot of moist, aerated soil. Taproots typically emerge within 24–72 hours.
- Transplant seedlings into their final container early — autoflowers don't love being repotted mid-life. A 7–11 litre fabric pot works well for this strain's compact root system.
- Keep your light schedule consistent at 18 hours on, 6 hours off. LSD-25 Auto doesn't need a dark period to flower, but the 6 hours off helps manage heat and electricity costs.
- Feed lightly during the first two weeks, then ramp up nutrients as the plant enters pre-flower around week 3–4. This strain responds well to a standard NPK feeding schedule — don't overdo the nitrogen once flowers start forming.
- Watch for the colour change in the final weeks. LSD-25 Auto is known for developing purple and reddish hues in the leaves and calyxes as temperatures drop at night. Cooler night temps (around 15–18°C) can encourage this without stressing the plant.
- Harvest when 70–80% of trichomes have turned milky with a few amber heads. With LSD-25 Auto, this typically falls around day 56–63 from germination.
- Dry in a dark, well-ventilated space at 18–22°C and 55–60% humidity for 7–10 days, then cure in sealed glass jars for at least two weeks. The earthy, musky terpene profile develops significantly during a proper cure.
LSD-25 Auto Specifications
| Specification | Detail |
|---|---|
| Seed Bank | FastBuds |
| Genetics | L.S.D. (Mazar-i-Sharif x Skunk #1) x Canadian Ruderalis |
| Type | Autoflowering, feminised |
| Dominant | Indica |
| THC | 19% |
| CBD | 1.1% |
| Seed to Harvest | 8–9 weeks |
| Height | 70–120 cm |
| Indoor Yield | 450–500 g/m² |
| Outdoor Yield | 50–250 g per plant |
| Available Pack Sizes | 3, 5, or 10 seeds |
LSD-25 Auto Compared to Similar Autoflowering Strains
| Feature | LSD-25 Auto (FastBuds) | Northern Lights Auto (typical) | Gorilla Glue Auto (typical) |
|---|---|---|---|
| Genetics | Mazar-i-Sharif x Skunk #1 x Ruderalis | Northern Lights x Ruderalis | GG#4 x Ruderalis |
| THC | 19% | 14–17% | 18–20% |
| CBD | 1.1% | Trace | Trace |
| Seed to Harvest | 8–9 weeks | 9–10 weeks | 9–10 weeks |
| Indoor Yield | 450–500 g/m² | 350–450 g/m² | 400–500 g/m² |
| Height | 70–120 cm | 80–120 cm | 60–100 cm |
| Dominance | Indica | Indica | Hybrid (Indica-leaning) |
The standout difference with LSD-25 Auto is the speed. At 8–9 weeks total, it's often a full week faster than comparable autos, and the 1.1% CBD is unusual — most autoflowering strains in this THC bracket carry only trace amounts. If you want something that finishes fast, yields generously, and carries a bit of CBD alongside its THC, LSD-25 Auto is the best autoflowering Indica for short-season growers.
Complete your setup with a grow tent and LED lighting if you're running LSD-25 Auto indoors. For outdoor growers in cooler climates, a fabric pot and quality organic soil mix will give these compact plants the drainage and aeration they need to hit their full yield potential. A carbon filter is worth considering too — the earthy, musky aroma from mature LSD-25 Auto plants is intense and carries.
Frequently Asked Questions
How long does LSD-25 Auto take from seed to harvest?
8–9 weeks from germination. That's the full lifecycle — no separate veg and flower periods to manage. You'll typically see the first pre-flowers around week 3, with the bulk of bud development happening in weeks 5–8.
What yield can I expect from LSD-25 Auto indoors?
FastBuds rates it at 450–500 g/m² under optimal indoor conditions. Realistically, first-time growers with a decent LED and proper feeding can expect 350–450 g/m². Experienced growers who dial in their environment regularly hit the upper end.
Is LSD-25 Auto suitable for outdoor growing in northern Europe?
Yes — the 8–9 week lifecycle makes it one of the better options for short summers. You can germinate in late May and harvest by mid-August. Outdoor yields range from 50–250 g per plant depending on sunlight, temperature, and growing medium.
Does LSD-25 Auto really turn purple?
It does. The purple and reddish hues are a genuine trait of this genetic line, not a deficiency. Cooler night temperatures (15–18°C) in the final two weeks encourage the colour change, but many growers report it happening even in stable indoor environments.
What does LSD-25 Auto smell like?
Earthy and musky with a sweet undertone. Think old-school Afghan hash rather than modern fruit-forward strains. The aroma intensifies significantly in the final two weeks of flowering and during the curing process. A carbon filter is recommended for indoor grows.
How does the 1.1% CBD in LSD-25 Auto affect the experience?
CBD is a non-intoxicating cannabinoid that research suggests may modulate THC's effects. The 1.1% CBD content is higher than most autoflowering strains in this THC range and is thought to contribute to a more physically relaxing experience compared to pure THC varieties.
Can I train LSD-25 Auto plants?
Light LST (low-stress training) works well — gently bending the main stem outward during weeks 2–3 opens up the canopy. Avoid topping or heavy defoliation; autoflowers have limited recovery time and aggressive techniques can reduce yield on a plant with only 8–9 weeks to live.
Last updated: April 2026
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Medical disclaimer. This content is for informational purposes only and does not constitute medical advice. Consult a qualified healthcare provider before use of any substance.