Jack F1 (Spliff Seeds) :: StrainReview :: Outdoor :: No.75879926725557436 by emeraldo

The weather in the growing area:

Cannabis-Plants into this zone can be cultivated from February to November. The plants will start flowering around July when the days slowly become shorter.

Harvest Time Outdoor

Middle of October in B^xlSa^β climates at the northern hemisphere.

Climate zones according to the SeedFinder classification with actual data from 1986-2009

Growth Behavior

Like a christmas tree

Side Branches

a great many; long as well as strong and vigorous.

The plants of this Cannabis-Strain...

...need place and should not be placed close together.

...do not need much care.

...are tolerant to over- or under-fertilization.

...do not need much fertilizer.

...are not vulnerable to fungal diseases.

...are not susceptible to mold.

...are tolerant of temperature fluctuations.

...looks and grow more like a Sativa.

...need a lot of room upward.

...should not be heavily pruned.

...respond well to the pruning of the main stem.

Yield / Quantity

The crop of this strain is great.

Buds / Leaves

The ratio of buds to leaves is very good.

Bud Structure

The dried buds are little bit fluffy.

Strength / Lasting Effect

The weed is strong and long lasting.

emeraldo says

Note on Jack F-1 Phenotypes, Bud compactness, and Effect:

I popped two Jack F-1 seeds and got two phenotypes. Both reached 8 feet tall, but the leaves on the one were fatter and shorter, and slender on the other. The sativa-looking plant was more vigorous and christmas-tree shaped with side branches creating a wider girth. The indica-looking plant had side-branches that were fewer in number, and her leaf morphology reminds one more of Spliff's White Widow （a "mostly indica" strain） than a sativa. See my photos comparing these two Jack F-1 phenos alongside Spliff's WW after about one month of veg, in early May.

I was puzzled at first because Spliff's states -- see Basic Info page above -- that "Jack F1 has an Indica appearance, but is definitely a Sativa." For me, that was confusing because the more vigorous plant, the one which got absolutely huge and produced the larger quantity of bud, was clearly a sativa-pheno that Spliff's did not mention. So at first I was not sure which phenotype was the pheno Spliff's had selected and back-crossed for. Now it is clear to me that Spliff's selected for what I am calling the indica-looker, designated as pheno #1 here on seedfinder.

"Jack F-1" growers will note that these phenos exist. By definition, an F-1 hybrid is a cross of two IBLs and is 50% stable. It can show variation from one individual to the next. Jock Horror is IBL, but numerous posts by Spliff's say the breeder used a Skunk F1 to produce "Jack F-1", so not all plants will have the indica look. By back-crossing with Jock Horror, the chances of getting the indica-looking pheno may have been locked in to a good degree, maybe 75% or 87.5%, depending on the number of BX.

My sativa-looker （pheno #2 here on seedfinder） produced an abundance of slightly fluffy buds （I've got 9 quart jars curing）. Her buds have some compactness -- there is a "hard" interior if squeezed -- but are slightly fluffy on the outside. A large amount of rough leaf material was also prominent on pheno #2, making manicuring messier. The indica-looker （pheno #1） actually has very tight and compact -- "hard" -- buds, which were much easier to harvest, manicure, and cure. See photo of finished bud.

There is no difference in effect as between the two phenos. Jack F-1's effect compares very well with that of the original Jack Herer, being a nicely balanced blend of stimulating and clear haze head high with a subtle and pleasant indica body buzz. When I grow Jack F-1 again, I will try to select for the indica-looking pheno in hopes of getting these highly compact buds. Compactness makes harvesting, curing, and smoking easier. (05.01.2020, 19:10)

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