Guava
Cannabis seeds
by Fast Buds
Guava Auto Cannabis Seeds by FastBuds
Guava Auto is an autoflowering cannabis seed from FastBuds that delivers a balanced 50:50 indica-sativa hybrid in just 8–9 weeks from seed to harvest. Bred from a carefully selected cross of indica and sativa genetics with ruderalis parentage, this strain packs dense, trichome-coated flowers into a compact plant that rarely exceeds 120cm. If you want proper autoflower genetics without sacrificing yield or potency, this is the one we'd point you towards.
Why Guava Auto Seeds Deserve a Spot in Your Grow
FastBuds have been refining autoflowering genetics for years, and Guava Auto shows what happens when a breeder actually nails the balance between speed and substance. Most autos force you to choose — fast but airy, or dense but slow. Guava Auto sidesteps that trade-off entirely. You're looking at a plant that finishes its entire life cycle in 8–9 weeks while still producing up to 450–550g/m² indoors and around 200g/plant outdoors. Those aren't wishful-thinking numbers from a seed catalogue; they're achievable with decent lighting and a sensible feed schedule.
The 50:50 indica-sativa split gives Guava Auto a growth structure that works in tight spaces. She develops a strong central cola with equally robust side branches, but stays between 70–120cm — short enough for a small tent, tall enough to produce meaningful canopy coverage. The ruderalis backbone means she flips to flower on her own schedule regardless of light cycle, which takes one variable off your plate entirely.
What we genuinely like about this strain: the flower quality punches above its autoflower weight class. Dried and cured buds come out rock-hard with thick calyxes, bright orange pistils, and a sugary trichome layer that catches the light. Some phenotypes develop pink and purple hues during late bloom — not just a marketing claim, but something you'll actually see if nighttime temperatures drop a few degrees during the final weeks.
Growing Guava Auto Seeds: What to Expect Week by Week
Guava Auto is one of the most straightforward autoflowers we've come across, and that's saying something given the number of seeds we've moved over the years. Here's what the grow cycle actually looks like.
During veg, you'll notice thin-fingered leaves — a clear nod to the sativa side of the genetics. Foliage is bright green, and the plant builds a sturdy central stem early on. Don't be tempted to top her aggressively; autos have limited veg time, and heavy stress training can cost you yield. Low-stress training (LST) works well if you want to open up the canopy. Bend the main stem gently and tie it down to expose lower bud sites to light.
When she transitions into bloom, expect some stretch. Not unmanageable — we're talking a plant that reaches 70–120cm at full height, not a sativa monster hitting the ceiling. The stretch fills out those side branches with bud sites, which is exactly what you want. By week 5–6 from seed, you should see proper flower development with resin production ramping up fast.
The one thing to watch: Guava Auto builds dense flowers, and dense flowers in a humid environment invite mould. Keep your relative humidity below 50% during late flower, and make sure air circulation is solid. A small oscillating fan pointed at the canopy makes a real difference. This is the honest limitation — she's not fussy about feeding or light schedules, but she won't forgive you for lazy climate control during the last two weeks.
Guava Auto Flavour and Effect Profile
The name isn't just marketing. Guava Auto produces flowers with a genuinely fruity terpene profile — think tropical sweetness with enough depth to keep it interesting. The aroma builds during the final weeks of flower and intensifies after a proper cure. Give your buds at least two weeks in jars before judging the flavour; fresh-dried Guava Auto is pleasant, but cured Guava Auto is where the full spectrum of tropical fruit notes comes through.
The effect leans towards the sativa side despite the 50:50 genetic split. FastBuds describe it as uplifting, focused, and functional — the kind of smoke you can enjoy during the day without losing the afternoon to the sofa. The indica influence shows up as a physical relaxation that sits underneath the mental clarity rather than replacing it. Compared to something like FastBuds' Gorilla Cookies Auto, which hits heavier on the body side, Guava Auto keeps you moving.
Guava Auto Specifications
| Specification | Detail |
|---|---|
| Seed Bank | FastBuds |
| Genetics | 50% Indica / 50% Sativa (Autoflowering) |
| Type | Autoflowering feminised |
| Life Cycle | 8–9 weeks from seed |
| Height | 70–120cm |
| Indoor Yield | 450–550g/m² |
| Outdoor Yield | Up to 200g/plant |
| Flower Structure | Dense, rock-hard buds with pink/purple hues |
| Seeds per Pack | 3 |
| SKU | CSFB0087 |
Running Guava Auto in a small tent? Pair her with a complete grow tent kit that includes lighting, ventilation, and a carbon filter — she's compact enough for an 80x80 setup with room to spare. If you're growing outdoors, grab some fabric pots in the 15–20L range to keep root temperatures stable and drainage sharp.
How to Grow Guava Auto Seeds
- Germinate your Guava Auto seeds using the paper towel method or by placing them directly into a moist jiffy pellet. Taproots typically appear within 24–72 hours.
- Transplant the germinated seed into its final container — autos don't like being repotted, so start in the pot you plan to finish in. An 11–15L fabric pot works well for indoor grows; go up to 20L for outdoor plants.
- Provide 18–20 hours of light per day throughout the entire life cycle. Guava Auto flowers automatically regardless of light schedule, but more light hours means more energy for bud production.
- Begin light feeding once the plant has 3–4 sets of true leaves. Start at half the manufacturer's recommended dose and increase gradually. Autos are sensitive to overfeeding — yellowing leaf tips are your first warning sign.
- Apply low-stress training (LST) during weeks 2–3 by gently bending the main stem away from centre and securing it with plant ties. This opens the canopy and encourages even bud development across multiple cola sites.
- Switch to bloom nutrients when you see the first pre-flowers, typically around week 3–4 from seed. Increase phosphorus and potassium while reducing nitrogen.
- Monitor humidity closely during weeks 6–9. Keep RH below 50% and ensure good airflow around the dense flower clusters to prevent mould.
- Harvest when 70–80% of trichomes appear milky white under a jeweller's loupe, with 10–20% turning amber. Dry in a dark room at 18–20°C and 55–60% RH for 7–10 days, then cure in glass jars for at least 14 days.
Guava Auto vs Other FastBuds Autoflowers
| Strain | Genetics | Life Cycle | Indoor Yield | Height | Character |
|---|---|---|---|---|---|
| Guava Auto | 50/50 Indica/Sativa | 8–9 weeks | 450–550g/m² | 70–120cm | Fruity, uplifting, functional |
| Gorilla Cookies Auto | Indica-dominant | 9–10 weeks | 400–600g/m² | 80–130cm | Heavy body, sweet cookies flavour |
| Lemon Pie Auto | Sativa-dominant | 9–10 weeks | 400–500g/m² | 80–120cm | Citrus, energetic, cerebral |
Guava Auto sits in a sweet spot: faster than both alternatives listed above, with yields that compete with the best in the FastBuds catalogue. If you're after a heavier body effect, Gorilla Cookies Auto is worth a look. If you want something more cerebral and citrus-forward, Lemon Pie Auto does the job. But for the best balance of speed, yield, and a versatile daytime effect, Guava Auto is the one we'd pick.
Frequently Asked Questions
How long does Guava Auto take from seed to harvest?
8–9 weeks total. That's the full life cycle — germination through to chop day. She's one of the fastest-finishing autos in the FastBuds lineup, making her a solid choice when you need a quick turnaround between grows.
Can I grow Guava Auto outdoors in a cold climate?
Yes. The ruderalis genetics give Guava Auto solid resilience against cooler temperatures and shorter growing seasons. She'll finish outdoors in most European climates as long as she gets at least 12–14 hours of sunlight daily. Expect up to 200g/plant outside.
Do I need to change the light cycle for Guava Auto?
No. Autoflowering seeds flower based on age, not light cycle. Run 18–20 hours of light throughout the entire grow for maximum yield. You can run 24 hours, but most growers find 18/6 gives the plant a rest period without sacrificing much production.
How tall does Guava Auto get?
Between 70–120cm depending on growing conditions. She's compact enough for a 60x60cm tent but responds well to LST in larger spaces. Indoor plants with good lighting tend to stay on the shorter side; outdoor plants with unrestricted root space can push towards 120cm.
What does Guava Auto smell and taste like?
Tropical and fruity — the guava name is earned, not just branding. Expect sweet, exotic fruit notes with some depth underneath. The flavour intensifies significantly after a proper 2-week cure in glass jars. During late flower, she gets loud — a carbon filter is strongly recommended for indoor grows.
Is Guava Auto good for beginner growers?
Absolutely. The autoflowering genetics remove the need to manage light cycles, and the indica-ruderalis backbone makes her forgiving of minor feeding and watering mistakes. The main thing to watch is humidity during late flower — keep it below 50% to protect those dense buds from mould.
How many Guava Auto seeds come in a pack?
Each pack contains 3 feminised autoflowering seeds. All seeds are feminised, so you won't need to identify and remove males — every plant that germinates will produce flowers.
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.