How to grow Auto Ultimate
- Breeder: Herbies
- Genetics: Mostly Sativa
- THC: up to 25%
- Type: Autoflower
- Difficulty: moderate
- Seed to harvest: about 10 to 11 weeks
- Flavors: berry, sweet, citrus
Sativa-dominant autoflower (Jack Herer x Cinderella 99 x Ruderalis) with 24-26% THC delivering a euphoric, creative cerebral high that mellows into a calming body buzz.
What is specific about Auto Ultimate
- Autoflower, avoid transplanting and heavy training; it can't recover lost veg time, so stress sets it back.
- Sativa-leaning, expect a big stretch when flowering starts; top early or run a net (ScrOG).
Indoor calendar for Auto Ultimate
| Stage | When | Note |
|---|---|---|
| Germination | week 1 | Seed in its final pot; autoflowers dislike transplanting. |
| Seedling and growth | weeks 2 to 4 | Light on 18 hours a day for the whole grow; no switch to 12/12 needed. |
| Flowering | from about week 4 to week 11 | Flowering starts by age, not by light. |
| Harvest | week 10 to 11 | Judge by trichomes, not the calendar. |
| Dry and cure | weeks 11 to 15 | One to two weeks drying, then at least two weeks curing in jars. |
About 13 to 15 weeks from seed to cured buds.
Week by week
Germination: Days 1–7
Pop the seed.
- Soak in a moist paper towel or plant 1cm deep in light, airy soil.
- Keep warm (22–25°C), humid and dark until the sprout appears.
- Moist, never soggy.
Seedling: Weeks 2–3
First true leaves.
- Gentle light on 18/6, high humidity (~65%).
- Tiny waterings near the stem; let the top dry between.
- Quarter-strength nutrients at most.
Vegetative: Weeks 4–6 (auto)
Build the plant.
- Autoflowers veg briefly then flower on their own, start in the final pot, don't transplant late.
- Feed grow (high-N) nutrients; train (LST/topping) for an even canopy.
- Sativa-leaning: leggier, give vertical room.
Flowering: ~6–7 weeks of bloom
Buds bulk up.
- Stays on 18/6 to harvest.
- Switch to bloom (high-P/K) nutrients; lower humidity (~45%) to prevent bud rot.
- Watch trichomes: mostly cloudy with some amber = peak ripeness.
Flush & harvest: Final 1–2 weeks
Finish clean.
- Plain water (no nutrients) the last 1–2 weeks for a smoother smoke.
- Harvest, wet-trim, dry slowly (~60°F / 60% RH, 7–14 days).
- Cure in jars 2+ weeks, burping daily at first.
~10–11 weeks seed to harvest.
Growing Auto Ultimate outdoors
Sown outdoors in mid May, after the last frost, Auto Ultimate should be ready in late July. That leaves time for a second run: a seed sown by early July finishes around mid September.
Drying and curing
Its berry and sweet notes come from the most volatile terpenes, the first to go in a warm, fast dry. Dry slowly around 18 °C and 60% humidity for 10 to 14 days and cure in jars to keep them.
How Auto Ultimate compares
At 10 to 11 weeks it sits right at the typical time for the 72 autoflowers in our guides.
Its THC, up to 25%, is above the typical 20% for these autoflowers.
Bred by Herbies, one of 50 Herbies strains with a grow guide here.
| Similar strain | Seed to harvest | THC | Breeder |
|---|---|---|---|
| Auto AK Triple Haze | 10 to 11 weeks | 20% | Dutch Passion |
| Auto Orange Bud | 10 to 12 weeks | 20% | Dutch Passion |
| CBD Auto Compassion Lime | 10 to 12 weeks | 10% | Dutch Passion |
| Auto Daiquiri Lime | 12 weeks | 20% | Dutch Passion |
Effects
uplifting, relaxing, euphoric, creative
Grower verdict: 8 reviews, average 4.75/5.
Questions
Is Auto Ultimate easy to grow?
Auto Ultimate is considered moderate to grow and flowers automatically without a light schedule change. This read draws on 8 grower reviews.
When is Auto Ultimate ready outdoors?
Sown outdoors in mid May, after the last frost, Auto Ultimate should be ready in late July. That leaves time for a second run: a seed sown by early July finishes around mid September.
How strong is Auto Ultimate?
The breeder lists up to 25% THC. Real results depend on light, feeding and harvest timing.
Does Auto Ultimate need a light change to flower?
No. Auto Ultimate is an autoflower: it flowers by age and goes from seed to harvest in about 10 to 11 weeks on 18 hours of light a day.
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