Grow Report – Colombian Jack

Welcome once again to a grow report on one of our Kannabia strains! In this detailed assessment, we’ll explore the different features of an outstanding strain that is much loved by growers of our genetics: Colombian Jack. We’ll document her development from germination to harvest, and we’ll show you how you can obtain amazing results by reducing her stretching using LST (Low Stress Training), a growing technique which is ideal to maximise the yields of indoor sativas.

For many cannabis growers, Colombian Jack is a gold mine with renowned genetics. In contrast with other newer strains that have much less of a track record, this beauty has become a classic in our catalogue in very little time. The fact that she’s a sativa-dominant strain with outrageously high THC levels (between 25 and 30%) has greatly contributed to this. Not for nothing did the strong power and precious flavour of this hybrid earn her first place as Best Sativa at Expogrow 2018.

What’s the origin of this strain?

Colombian Jack has been created by Kannabia from the cross of Black Jack and Nebula. Black Jack, a strain with a high THC count, derives from the cross between the native variety Black Domina and the famous Jack Herer. These are robust and reliable genetics that also showcase amazing aroma and flavour profiles. For her part, Nebula originates from the cross of American Haze and Master Widow. Although she has lower THC levels, she’s won numerous prizes for her syrupy flavour and balanced effect.

The result of this union is Colombian Jack, a sativa-leaning strain (70/30) that certainly lives up to her name. She’s an adaptation of native varieties, so she shows a development inherent to her natural evolution, thanks to a long-standing lineage which rewards patient growers (her flowering can take up to 10 weeks) with lots of orange green buds, in a plant that has the promise of long days of enjoyment hidden up her sleeve.

How is its aroma and flavor?

Simply holding a Colombian Jack bud in your hands is enough for you to recognise her distinct citrus and pine aroma with floral and woody notes. A scent that will make you feel as if you were simultaneously inside a field of orange trees and a boreal forest. Many users compare this aroma with a mix of grapefruit, lime, musk, and incense. If you appreciate cannabis terpenes, you’ll have a blast with her high content of the spicy beta-caryophyllene, the citrusy limonene, and other minor terpenes such as humulene, pinene, and bisabolol, which add complexity to her organoleptic palette.

If you’re not an avid smoker, though, you might find the smoke of Colombian Jack rather strong. In contrast, her flavour fuses together the zest of citrus fruits and bursts of herbal and spicy notes which are equally delicious and appetising. All of these result in a strain with an old-school flavour profile that delivers a really tasty and pleasurable experience, making her a hugely popular choice amongst fans of sativas with Haze features.

What effects does it produce?

After just a few hits of Colombian Jack, you’ll quickly understand why she’s been the winner of so many awards. Her high is as balanced as it is energising, and users claim they feel relaxed, euphoric, and generally happy after savouring her. This is the perfect strain to use to create art, or to simply have while watching a film; although she also has a powerful ability to help you do things with a clear and focused mind. With a slow-burning but long-lasting high, she’ll leave you with a great sense of well-being that will keep you stress-free throughout the day.

How do indoor plants grow?

Given her hybrid nature, Colombian Jack starts growing with an indica appearance, but she quickly develops a typically sativa structure, turning into what you would probably expect: a tall, dense, and uneven plant. Best to keep an eye on her if you’re growing her indoors, and even apply a pruning or training technique to make sure she doesn’t grow up to the ceiling.

Nonetheless, that capricious physical appearance is balanced out with her high potency and yielding capacity. This plant develops plenty of loose leaves, which are more widely separated than what you might be used to. Her big buds become elongated around the pale green leaves, producing masses of resinous trichomes which shine in the light.

This might not be an easy option for rookie growers because of her excessive stretching, but it is actually this feature that makes Colombian Jack a healthy challenge for those wanting to try growing techniques such as Low Stress Training (LST)!

Let’s now see how a seasoned grower has applied this training technique to his Colombian Jack grow.

Colombian Jack’s step-by-step grow guide

• Grow type: Indoor
• Lighting: LED / 680W Mars Hydro FC 6500 + LED / 45W Custom
• Grower: Cyrusdavirus
• Number of plants: 1
• Nutrients: Earth Dust Base / Earth Dust Boost
• Irrigation: Manual
• Training: Mainlining / LST / Defoliation
• Vegetative phase: 6 weeks
• Flowering phase: 9 weeks

Germination phase

The grower starts his venture by putting 1 Colombian Jack seed in a container with water and a few drops of hydrogen peroxide, for a period of 24 hours. After that time, he puts the seed inside a pressed peat pellet. Germination is successful, and the first cotyledons start to emerge from the 3 cm stem after 5 days.

During the first week, and once the roots start to protrude from the peat pellet, the seedling is transplanted to a 7 gallon (26.5 L) pot, with substrate enriched with Earth Dust Base (organic nutrients for living soils), with 20% perlite to promote oxygenation and a little mycorrhizal life (Dynomyco). The seedling, which is already developing its first true leaves, is placed 40 cm below the LED Mars-Hydro lamp at low potency, with a photoperiod of 18 hours of light and 6 hours of darkness. The following initial grow parameters are established:

Grow parameters:

• Daily temperature: 26ºC
• Height: 0 – 3 cm
• Substrate temperature: 24ºC
• Night temperature: 21ºC
• Hours of light: 18
• Air humidity: 60%
• Total dissolved solids: 300 ppm / 0.6 EC
• Irrigation volume: 0.19 L per plant per 24 hrs
• Distance between lamp and plant: 40 cm

Seedling / vegetative phase

During the second week, the grower installs additional UV-IR lighting bars, which are designed to adapt to the Mars Hydro FC 6500 that he’s already using. The seedling has already grown up to a height of 15.24 cm, developing multiple sets of true leaves. It seems to be happy in its new home, so the grower decides to elevate the lamps to a height of 90 cm, keeping the rest of the grow parameters unchanged.

In the third week, Colombian Jack has grown enough for LST to be applied. The grower first concentrates on mainlining the plant to alter her structure and generate two main stems, concentrating the growth on several main colas. He finishes with a little LST to bend the two main branches into a Y shape, holding down the two lines which will give way to the rest of the branches with metal pegs anchored to the substrate. During the following week, he will slowly stretch them out horizontally.

LST can be started as soon as the plant is big enough to be tied up, but only when she has a minimum of 2 or 3 nodes. During this stage, the main stem is still very flexible, and the root system has started to form a dense ball, so it’s the perfect time to start bending.

In the fourth week, it’s time for another round of topping for the two main stems created with the mainlining, so that they turn into 4 stems. It is essential to wait until the cannabis plant has recovered and grown further before topping again. The different branches continue being anchored to the substrate so that the plant grows horizontally, generating more shoots.

In the fifth week, the plant keeps growing at a good pace, so the grower decides to change the light cycle to 12 hours of darkness to initiate the pre-flowering period, while he raises the potency of his LED FC 6500 to about 600W to enter the following phase with plenty of momentum.

Over the course of week six, flowering as such hasn’t started yet, although with the 12/12 photoperiod you can start to see what the grower calls “pistil hairs” here and there. The leaves are getting bigger and bigger, which translates into more photosynthesis and better growth and health.

Grow parameters:

• Daily temperature: 26ºC
• Height: 25.4 cm
• Substrate temperature: 24ºC
• Night temperature: 21ºC
• Hours of light: 12
• Air humidity: 60%
• Total dissolved solids: 300 ppm / 0.6 EC
• Irrigation volume: 0.95 L per plant per 24 hrs
• Distance between lamp and plant: 60.96 cm

Early flowering phase

In week 7, once the light cycle has been changed, the plant keeps stretching, showing her first whitish stigmas on the tips of the branches. The colour of the leaves is a perfect deep green. The grower trims the lower leaves to help reduce moisture.

Between the eighth and ninth week, the stretching stops, and you can see the continuous development of the whitish buds. Our Colombian Jack rises proudly to a height of only 40 cm, but she starts to show beautiful colas on all her main branches. Thanks to LST, all the apical meristems showcase a strong and hardy consistency. The shoots are full of pistils and will be able to withstand however many the plant ends up producing.

Full flowering stage

In week ten, the terminal buds have swollen into large, dense colas, whereas the lateral branches have developed slightly smaller tips. Most of the stigmas are white, but a few have started turning red and orange, which signifies that the flowering is in full swing.

In week 11, the apical meristems and every tip of the branches are colonised by a mass of growing pistils. The trichome layer also increases dramatically, and the plant starts releasing a heady citrusy aroma.

During week 12, this lovely lady is ripening well, completely covered in a sticky frosty layer, and the pistils now begin to change colour all at the same time. Her looks are spectacular, with 8 main colas at the upper horizontal level, which hold more than a dozen large secondary buds on the subsequent lower levels.

Grow parameters:

• Daily temperature: 26ºC
• Height: 38.1 cm
• Substrate temperature: 24ºC
• Night temperature: 21ºC
• Hours of light: 12
• Air humidity: 60%
• Total dissolved solids: 300 ppm / 0.6 EC
• Irrigation volume: 0.95 L per plant per 24 hrs
• Distance between lamp and plant: 60.96 cm

Ripening stage

In week 13, a dense trichome layer covers the buds and the sugar leaves. All the final energy of the plant is focused on the production of flowers, which now appear in all their splendour. At this point, the trichomes are starting to turn milky white and are swelling up considerably. The sugar leaves are turning dark green, and it’s clear that harvest time is just around the corner.

We reach week 14 and the grower carries out the last defoliation when he sees that the trichomes start to change, or, in his own words, “when amber comes to help” (laughing). He’s also been reducing the potency of his FC 6500 to protect the stunning trichomes and the terpenes (too much light or heat can evaporate this important sticky substance).

By week 15, Colombian Jack has finished growing, and her buds have reached their final calibre, with calyxes that have swollen up substantially. A citric and fruity aroma with earthy hues envelops the whole tent. Before harvesting, the unwanted biomass is cut to help eliminate additional moisture. The grower is ready to dry, without having modified the grow parameters until this point. All’s well that ends well!

Harvest

The final yield of our Colombian Jack, grown using the LST technique, amounts to 425 grams of fresh buds. With a 725W LED light and using a 1.22 m² grow space, the light – output performance averages out to 594.26 watt / m².

Once the buds are cut and dried, the result is 103 grams of dry flowers of a potent sativa that could easily steal your heart. The trimmed flowers are rather spicy, and they ooze sweet and spiced notes with an earthy background… An aromatic bouquet that genuinely reminds you of the tropics, and will make you dream of being on a Caribbean beach, all chilled out and laid back, as soon as you have the first puff.

So that’s our Colombian Jack, a plant as complete in her organoleptic qualities as she is vigorous and wild in the way she develops. She’s one of those genetics that stands out in almost every possible way. And even though she can express herself to her full potential when grown outdoors, where she can reach heights of up to 3 metres, she can also be a real winner indoors if you choose to keep her under control. So don’t waste any time to get your Kannabia seeds and try her for yourself!