Sexing

What are preflowers?

Preflowers, as opposed to full blown flowers, generally appear after the fourth week of vegetative growth from seed. Check carefully above the fourth node. Please note that preflowers are very small and and almost impossible to differentiate without magnification. A photographer's 10x loupe is handy indeed when examining preflowers.

As the images below demonstrate, the female preflower is pear shaped and produces a pair of pistils. Frequently, the female preflowers do not show pistils until well after the preflowers have emerged. Thus, don't yank a plant because it has no pistils. Pistillate preflowers are located at the node between the stipule and emerging branch.

Also, some female preflowers never produce pistils. A female preflower without pistils is difficult to distinguish from a male preflower. Thus, hermaphodite issues should not be resolved by the appearance of preflowers, without pistils, on a plant otherwise believed to be a female.

Female (pistillate)




Female (pistillate)



The male preflower may be described as a "ball on a stick." However, its most recognizable feature is its absence of pistils. Sometimes, a male plant will develop mature staminate flowers after prolonged periods of vegetative growth. These appear in clusters around the nodes.

The following image shows a male plant in early flowering. Staminate flowers are located at the node between the stipule and emerging branch.

Male (staminate)













These pictures and quotes were donated from a sexing thread about identifying females by their pre-flowers (primordia) which was authored by "Crazy Composer". The pictures alone speak a thousand words...




Note: The plant parts marked with an "X" are called "stipules", they appear on both male and female plants.


This diagram shows the difference (on a slightly more mature plant) between genuine pre-flowers and actual bud sites, which are - in fact different animals altogether.



From a further distance, but quite clear-cut.
I know how it is for some of the newer growers who are eagerly anticipating their first view of an actual marijuana flower. Well, this is what it looks like, play your cards right and you'll have thousands of these hairs clumped tightly together and covered in crystals that will smell so nice. Don't worry, it's coming.





What does an emerging MALE preflower look like?


Identifying a true preflower is way to tell sex before 12/12. That way you can take clones from the known females without wasting the time and space on males.

Note:
(Kifit) "do not try to sex a seedling based on the very first preflower you see with a 25x times microscope.....wait and make sure. The time between using a 25x to spot the very first preflower sex and the plant dropping pollen is at least 10+ days away and so it's safe."

"It's best to cull a male only after you are 101% sure - when you see 2 or 3 (or more) immature male flowers bunched together on the internodes or the top growing tip - this is a male, for sure, females preflowers have white " spears " that appear in a vee. ..but "every now and then a sexually indistinguishable flower appears" (Ed Rosenthal)

After a few weeks in veg, plants will begin to show their sex. Usually the males show first. The male preflower is a miniscule ball. It appears that there is a small piece of foliage that covers the ball and protrudes outward when the male preflowers first appear.

The following pics show MALE preflowers the FIRST day they show their future pollen distribution centers.

Many times preflowers will appear at the fourth or fifth node, whereas the plant is on the 7th or 8th node. These preflowers usually don't develop into full flowers, but are only an indicator of the plants sex.





Female on left, male on right. Im only certain about the sex cause I watched them several more days. 25X magnification.

After 10 days flowering, what does a female look like?

The following image clearly displays a female plant at about 10 days flowering, using a 400w HPS. NOTE: Indica dominant strains will flower faster than Sativa varieties.










After 10 days flowering what does a male look like?

The following image displays a male plant at about 10 days flowering.










How do I sex using a paper bag?


Get a small paper bag or something similar that is lightproof (a paper bag will not be suitable for strong H.I.D lighting), and a plastic coated twist tie.

Select a plant that you would like to sex and choose a growing tip. Take the paper bag, place it over the top of the selected tip and seal with the twisty tie. Then, to simulate the flowering phase, simply remove the bag after the 12hr dark period, and replace when the 12hr day cycle ends.

After 7-14 days, the growth-tip you covered should start showing signs of its sex.

Editor's note:
Caution should be taken when closing the bag too tightly around the branch.
A small opening should be left open to allow air exchange and prevent heat buildup. Black materials tend to heat up and the branch may suffer from excess heat, causing wilting.

(10k)
"There is plenty of air inside the paper baggage because it would hold its own blown up shape...sorta balloned over the branch tip."


This is for people that dont have room for clones or just want to know the sex of there plant without takeing and rooting early cuttings.

Things you need:
1 can of black spray piant
1 box of plastic ziplock baggie (sandwich bag size)

Take the plastic baggie and spraypaint the outside of the baggie, then find one of the lower branches that is furthest from the light (this will insure that light reflection on the black paint isnt too intence for heat buildup)and just simply slip the baggie over the branch for 12 hours of darkness.

If you have painted the whole baggie, then no light will get through to the branch when the lights are on. You will see sex on that one branch in 7 to 10 days in most cases.



Flower Biology

A bud is a cluster of single female flowers.

As you can see in the pic, this cola is composed of several sub-units that are will fill out before reaching maturity. In this phase, the plant has finished the stretching phase and is developing bud sites.

Depending on the strain, bud development may start in the middle of its flowering period.





What is an hermaphrodite?

An hermaphrodite, or hermie, is a plant of one sex that develops the sexual organs of the other sex. Most commonly, a flowering female plant will develop staminate flowers, though the reverse is also true. Primarily male hermaphrodites are not as well recognized only because few growers let their males reach a point of flowering where the pistillate would be expressed.

Hermaphrodites are generally viewed with disfavor. First, they will release pollen and ruin a sinsemelia crop, pollinating themselves and all of the other females in the room. Second, the resulting seeds are worthless, because hermaphrodite parents tend to pass on the tendency to their offspring.

Please note that occassionally specious staminate flowers will appear in the last days of flowering of a female plant. These do not drop pollen and their appearance is not considered evidence of deleterious hermaphroditism.

Here's an image of a hermaphrodite, specifically a female plant with staminate flowers.

nice post cheers for the info > rep