How to Grow Colombian Jack
Colombian Jack is a sativa-dominant hybrid that pairs the pure energy of a Colombian landrace with the iconic, award-winning Jack Herer. It delivers a soaring, creative and euphoric high and an earthy, citrus and spicy aroma. As a photoperiod strain it flowers only when you shorten the light cycle, which gives you full control over its long, rewarding bloom. This guide walks you through the whole grow, from germinating the seeds to the final cure.
It is a tall, vigorous sativa that stretches hard and runs a long 9 to 12 week flowering. It takes planning and training to tame, but the payoff is long, elegant, aromatic colas. This one rewards an experienced hand rather than a first grow.
Recommended Strains
Colombian Gold
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THC | 16% - 19% (Medium) |
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Type | Feminized |
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Yield | Medium |
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Phenotype | 25% Indica / 75% Sativa |
Blue Colombian Kush
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THC | 15% - 23% (Medium) |
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Type | Feminized |
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Yield | High |
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Phenotype | 70% Indica / 30% Sativa |
Colombian Jack at a Glance
Before you plant anything, it helps to see the full picture in one place. Here is the quick profile for this tall, energetic sativa, taken from Blimburn’s published grow guide for the strain.
| Seed type | Photoperiod |
|---|---|
| Genetics | Colombian landrace x Jack Herer |
| Type | Sativa-dominant hybrid |
| Flowering time | 9–12 weeks |
| Height indoor | 3–5 ft (100–150 cm), trained |
| Height outdoor | up to 10 ft (300 cm) |
| Climate | Warm, long, sunny season |
| Flavors | Earthy, citrus, spicy |
| Effects | Energetic, creative, euphoric |
With its heavy sativa lean it sits firmly among the sativa seeds, and its Jack Herer heritage puts it right at home with the Jack Herer strains. If you are still weighing options, the find your strain tool helps you match it against the rest of the catalog.
Colombian Jack’s published grow data does not list a THC percentage, exact indica/sativa split, yield figure or terpene breakdown, so those are not stated here rather than estimated.
Promos & Deals
How to Germinate Colombian Jack Seeds
A healthy harvest starts at germination. Give the Colombian Jack seeds a 12 to 24 hour soak in room-temperature water, then move them to the paper towel method: fold them between two damp sheets, keep them warm and dark inside a bag or between two plates. A white taproot can take anywhere from 48 hours to 10 days with a landrace-heavy sativa like this, so be patient.
Once the taproot shows, plant it about half an inch deep in a starter pot with the root pointing down. That new taproot is delicate, so use tweezers and a gentle touch when you move it to avoid any check to its growth. Keep the medium lightly moist and give soft light while the first true leaves open.
Starter tips
- Be patient: landrace sativa seeds can take up to 10 days to pop.
- Handle the fragile taproot with tweezers and a gentle touch.
- Use plain, lightly pH-balanced water (pH 5.5 to 6.5) for the first week.
Growing Colombian Jack in the Vegetative Stage
During veg, Colombian Jack does what sativas do best: it stretches, building a tall, strong frame. Keep it on an 18/6 light cycle for vigorous growth and feed a balanced grow fertilizer with a good amount of nitrogen to support its leafy development. It wants a warm climate with a long season to suit its landrace roots.
Training is mandatory here, not optional. Because it grows so tall, topping early and running a SCROG (screen of green) net are the best ways to tame its vertical stretch indoors and dramatically improve your yield. Both techniques spread the plant into a wide, even canopy so light reaches every bud site instead of one towering cola.
Flowering and Buds of Colombian Jack
To trigger flowering, switch Colombian Jack to a strict 12/12 light cycle. Its bloom is long, a true sativa trait, typically 9 to 12 weeks. The plant stretches even more early in flower, then slowly develops long, elegant colas that fill the space with an earthy, citrus and spicy aroma. Switch to a bloom feed higher in phosphorus and potassium once you flip the lights.
Keep good airflow throughout bloom. Those long sativa colas can get dense, so an oscillating fan is critical to stop moisture getting trapped, and a carbon filter helps with the strong, pungent aroma indoors.
On the effect side it is energetic, creative and euphoric, a soaring, inspired high that is made for daytime use and reflects its pure sativa roots.
Common Problems and Pro Tips
Colombian Jack is a rewarding grow, but its height, long bloom and dense colas point to a few things worth watching.
- Plan for the height: it reaches 3 to 5 ft indoors even trained and up to 10 ft outdoors, so top it and run a SCROG net, and give it real vertical space.
- Prioritize airflow: its long colas trap moisture, so keep an oscillating fan running and watch humidity closely in late bloom to prevent mold.
- Be patient: with a 9 to 12 week flower it rewards a grower who waits, so do not rush the finish.
Expert tip: you can clone Colombian Jack. Take a healthy 4 to 6 inch cutting from a lower branch of a mother in veg, dip it in rooting hormone, set it in a moist starter cube under a humidity dome, and in about two weeks you will have an exact genetic copy of your favorite plant.
Aroma, Flavor and Effects
The nose is bright and complex: a sharp citrus lift over an earthy base, rounded out with a spicy, peppery edge. It is a classic landrace-sativa profile, carrying the fresh, volatile citrus and spice that define its Jack Herer side.
The flavor follows the nose, zesty citrus and warm spice over an earthy finish on the exhale. On the effect side it is energetic, creative and euphoric, a soaring, inspired high that leans firmly toward daytime use. It is the kind of lift that makes you feel ready to take on the world.
Nutrient Schedule
Treat the figures below as a starting map, not a rulebook. Colombian Jack wants plenty of nitrogen in veg and a phosphorus and potassium rich feed in bloom, so read the plant first: tip burn means back off, while pale, slow growth means it wants a little more. All values use EC.
| Stage | EC |
|---|---|
| Seedling | 0.4–0.6 |
| Growth | 0.8–1.2 |
| Early flower | 1.2–1.4 |
| Full flower | 1.4–1.6 |
| Flush | 0.0–0.4 |
Keep the pH around 6.0 to 6.5 in soil and 5.5 to 6.0 in hydro so the roots can actually take up what you feed.
What to Do With Your Trim: Live Resin and Extracts
A sustainable grower knows the trim is where the flavor lives, and with a strain as aromatic as Colombian Jack a terpene-rich extract is the best way to honor it. Its frosty trim is ideal for high-quality live resin or BHO, which capture the fresh, volatile citrus and spice that define its aroma and taste. That is the ultimate way to experience what makes this plant special. The bare stems will not extract, but chopped and composted they feed organic matter back into the soil for your next grow.
Harvesting, Drying and Curing Colombian Jack
Timing the harvest comes down to the trichomes. Grab a jeweler’s loupe and, for that classic energetic sativa high, harvest when the trichomes are all cloudy with very few, if any, amber ones. With a 9 to 12 week bloom, this long-flowering sativa asks for patience right to the end.
After the cut, trim away the large fan leaves and hang the branches in a dark room with good airflow at 60 to 70°F and humidity around 45 to 55%. Slow beats fast: drying over 7 to 14 days protects the earthy, citrus and spicy aromas that define this strain. When the small stems snap instead of bending, move the buds into jars.
Cure in sealed glass jars, burping them daily for the first couple of weeks to let moisture escape. For a sativa like this, a long, slow cure of at least 3 to 4 weeks, and ideally longer, is what smooths the smoke and brings its citrus and spice fully forward. It is the step most growers rush.
Frequently Asked Questions
How long does Colombian Jack take to flower?
Colombian Jack has a long bloom, typically 9 to 12 weeks, which is a true sativa trait. The plant stretches even more early in flower before developing long, elegant colas. That extended flowering is part of why it needs a warm, long season, especially when grown outdoors.
How tall does Colombian Jack grow?
Colombian Jack gets tall. Indoors, even with training, expect 3 to 5 ft (100 to 150 cm), and left unrestrained outdoors it can become a tree of up to 10 ft (300 cm). Vertical space is a major consideration, so topping and a SCROG net are essential to keep it manageable indoors.
Is Colombian Jack good for beginners?
Colombian Jack is better suited to growers with some experience. Its tall, stretchy sativa frame makes training mandatory, and its 9 to 12 week bloom tests your patience. None of it is especially difficult, but the height management and long cycle reward a grower who has a grow or two behind them.
Why do I have to train Colombian Jack?
Because Colombian Jack grows so tall and stretchy, training is mandatory rather than optional. Topping it early and running a SCROG net tames its vertical growth and spreads it into a wide, even canopy. That dramatically improves your yield indoors and keeps the plant from outgrowing your tent.
What are the effects of Colombian Jack like?
Colombian Jack delivers a soaring, energetic, creative and euphoric high, the inspired, daytime lift you would expect from a Colombian landrace crossed with Jack Herer. It leans firmly cerebral and uplifting, making it a strain for getting things done rather than winding down at the end of the day.
What does Colombian Jack taste like?
Colombian Jack leads with a sharp, zesty citrus flavor over an earthy base, finished with a warm, spicy edge. It is a classic landrace-sativa profile rather than a sweet one. Both the aroma and flavor sharpen noticeably with a long, slow cure after harvest, bringing the citrus and spice forward.
