
Strain Profile
Breeder
NIRVANA SEEDS
Cup Winner
No
Medicinal
No
Flowering Type
Standard
Yield
High
THC Content
High (15-20%)
CBD Content
Low (0-1%)
Environment
Indoor, Outdoor, Greenhouse
Genetics
Mainly Sativa
Height
Medium
Flowering Time
8-9 WEEKS
Black Jack

NIRVANA SEEDS
In 1995 Nirvana was officially founded by Mau. From its origins as a cannabis seed specialist, Nirvana has grown into an innovative business concept. Its unique and original range of carefully crafted hemp products serves to expand the usage of this extraordinary plant further than ever before.Product Overview
Same Day Dispatch Information
We will always strive to dispatch orders for special delivery placed before 10am on the same working day, however please note all orders are subject to our usual processing time of upto two working days. Quoted delivery time is from point of dispatch.
Free Cannabis Seeds
Everybody loves freebies right?
When you shop at the London Seed Centre you are guaranteed a minimum of one free seed with every order.
The more you spend the more free seeds you’ll receive bundled in with your order.
What’s more, our freebies are some of the most popular strains on the market provided by the most reputable manufacturers, so rest assured you won’t be disappointed!
Quantities and strains adjust with order size and value
Don’t forget to sign up to the London Seed Centre today to claim your seed chips for extra discounts on your orders, plus a load of bonus perks for being a valued LSC member.
*Kindly note that free seeds strains are subject to availability, and may be swapped out with different strains if they become out of stock. We alway do our best however to supply a strain of similar characteristics to the seeds on your order. Thank you for understanding.
Ask a Question
Product Overview
Blackjack seeds will grow into a super hybrid that delivers delicious earthy flavors and a fast flowering period. She has a high resilience to cold and wet weather and works wonderfully during short Summers. Growing Blackjack outdoors is advised as she likes to stay low, making her great for those who need discretion and a fast blooming strain.
She is a feminized strain that displays true hybrid vigor, bold earthy pungent flavors and produces an exhilarating high. A fine blend of indica and sativa genetics that takes between 8–9 weeks to flower.
Black Jack seeds will grow into a low profile plant that is best for growers with experience growing sativas and more challenging cultivars. Overall, a wonderful strain for anyone who spends the time to train their plants, and a superb choice for SCROG.
We created Blackjack cannabis seeds by crossing the super potent indica Black Domina with our Jock Horror. We managed to produce offspring that enhanced the yield and effect of the Jock Horror whilst retaining the high resilience and flavor profile from the Black Domina side.
A fine choice for growers looking for a fast finisher with a high plant resistance that will express a sativa dominance whilst growing.
Blackjack is a low profile hybrid despite her sativa influence, meaning that she will grow medium height, so a fine choice for bedroom growers or those with limited space.
Her growth structure is more Black Domina dominant during the vegetative phase, so will grow with short internodal spacing, resulting in a small stretch once flowering begins.
Plants will be ready to harvest after 8-9 weeks of flowering, where the buds will swell into large sized nugs coated in resin.
Outdoors, Blackjack seeds will grow into short and stocky plants, with a bushy structure and profile. Once flowering starts, the plants will stretch and double in size, making them medium height.
She is a very productive plant that will produce great results in all climates, and will perform especially when in a hot climate such as California.
Thanks to her blend of indica and sativa genetics, Blackjack Feminized will have a high resistance to all types of weather. She can fight off mold and mildew and can endure heat stress with no problems.
Under HID lighting, plants will require 8-9 weeks before they are ready to harvest. Some phenotypes will take longer than others, and we advise inspecting the trichomes after week 8 to make sure you have the optimal harvest window.
Outdoors, Blackjack can take between 56-65 days depending on the climate, location, and pot size. It is recommended to plant the seeds outdoors in Spring time, with a harvest date of early October.
Yields of 450 g/m² (1,5 oz per square foot) can be achieved indoors under HID lighting, and fed nutrients. With longer vegetative times and applied training, it is possible to enhance yields even further.
Outdoors, it is possible to harvest 650 grams (22 oz) per plant can be achieved under the right circumstances. For the best yields possible, keep the plants in a South-facing location.
The final height of the plants once full stretched will be around 100 cm (39 inches) tall, making her a low profile hybrid.
Her growth structure will be similar to the Black Domina parent, and grow with a medium tall central cola, with bushy wide branching.
Blackjack Feminized react very well to topping, tying down and pruning. We advise growing her through a screen for the biggest yields possible, and to maximize your indoor space if limited with room.
Some plants may require staking with bamboo or a net trellis to help support the heavy yielding side branches.
One of the best things about this girl is her aroma and flavor. Blackjack will have an overwhelmingly pungent odor that is a combination of earth, citrus, spices, and lemon.
Her flavors are bold and long-lasting, encouraging a licking of the lips after every pull of a joint. A concoction of pungent, dank, citrus will coat the mouth with a moorish flavor that you will quickly grow to love.
When smoking a joint of Blackjack, the effects will be an immediate sensation of focus, motivation and pure mental energy. Well recommended for busy individuals who need to remain sharp during a working day. Furthermore, an excellent choice for starting the day right with a fresh cup of coffee to stimulate the mind and all senses!
Her THC levels will range between 16-20% with a CBD of 0.1-1% making this strain ideal for morning and daytime use, or those who do not want the effects of powerful indica strains. Medical patients may find Blackjack will improve feelings of well-being, helping lower depression and grow motivation.
MORE GOOD REASONS TO SHOP AT THE LONDON SEED CENTRE
Free delivery
Choose Next Day Delivery
International Recorded Delivery
London Seed Centre Order Delivery Information
At London Seed Centre, we aim to provide fast and reliable shipping for all our customers. Please note that all orders are subject to a processing time of up to two working days, and quoted delivery times apply from the point of dispatch.

UK & Northern Ireland Shipping Methods
Standard Recorded Delivery™ (3-7 Working Days From Dispatch)
Delivered within 3-7 working days.
Includes online tracking and proof of delivery.
Royal Mail Signed For™ 1st Class (2-5 Working Days From Dispatch)
Aims to deliver within 2-5 working days.
Includes online tracking and proof of delivery.
Special Delivery Guaranteed Next Day™ (From Dispatch)
Next-day delivery from the date of dispatch.
Confirmation email and tracking number provided upon dispatch.
Free Delivery for Seed Orders
Orders over £50: Free standard recorded delivery for UK seed orders.
Headshop Items Shipping Methods
Free Delivery
Orders over £50: Free standard recorded delivery for smaller, lighter items.
Orders over £100: Free standard recorded delivery for heavier, bulkier items. (Applies to headshop items only – excludes seeds and other items.)
Standard Recorded Delivery (3-7 Working Days)
Under 1kg: £5
1-3kg: £8
Over 3kg: £10
First Class Recorded Delivery (2-5 Working Days)
Under 1kg: £6
1-3kg: £10
Over 3kg: £12
Special Delivery Guaranteed Next Day™ (From Dispatch)
Flat fee: £15 (regardless of weight).
International Shipping
International Signed For™
Secure, tracked service available worldwide.
Items tracked until they leave the UK and in some overseas destinations.
Delivery Aims:
Europe: 3-10 working days.
Rest of the World: 5-15 working days. (Delivery times exclude day of posting, Saturdays, and Sundays.)

Further Information
Airsure®
Priority handling in the UK and abroad.
Generally 1 day faster than standard Airmail.
Delivery Aims:
Western Europe: 2-3 working days.
Eastern Europe: 3-4 working days.
Rest of the World: 6-7 working days.
Note: Delivery times are not guaranteed, and compensation is not available for delays or missing tracking.
Airmail
Reliable service for lighter international mail.
Delivery Aims:
Western Europe: 3 working days.
Eastern Europe: 5 working days.
Rest of the World: 5-7 working days.
Returns & Replacements
You can exchange an unwanted item for a replacement or store credit of the same value if the item is still in the original breeder packet and remains UNOPEN. We will not under any circumstances exchange or replace an open packet. NO REFUNDS.
RETURNS & REPLACEMENTS
You can exchange an unwanted item for a replacement or store credit of the same value if the item is still in the original breeder packet which remains sealed. We will not under any circumstances exchange or replace an open packet. Due to the nature of our products, we cannot give refunds. Kindly note that any items being sent back to us should be sent by recoreded delivery, and the tracking number sent to us by email to [email protected].
Login and Registration Form