One of the worst possible occurances can happen after you spent all of that time raising your girls only to find out some stud sneaked in while you were sleeping and wants to play with your little girls. Here's a compilation I picked up from looking at numerous other sites and drawing the same conclusions we have here. But you can never spend to much time on sexing. There's a thousand threads on it and there will be a thousand more before we are through. This is after all a place of old timers and newbies alike to join together with information. I would imagine that there are at least ten new grower's who read these threads each and every day and some are just a little scared of sounding dumb in not being able to tell the difference between male and females. Don't be. There wasn't one single guy among us who had an absolute for certain idea of what we were doing when we started our first crop. So I will try to post some photos as they are really rare from most growers who avoid male plants like the plague and bugs. As I find them on other sites, I will post them here. So grab a smoke, kick back and if you are an old timer, remember back the first time you spotted that cluster of balls and how proud you were of yourself for catching them in time. For you new guys, pay attention. This is really important stuff: By now your plants have been growing for awhile and you've entered the 12/12 light cycle. You are now in the pre-flowering stage. At this point it is very important to keep a daily watch of your plants, and investing in a magnifying glass isn't a bad idea. Unless you are planning on breeding (not cloning, but breeding), then you will be destroying your MALE plants as soon as you can define their sex. Look at the attached photos. With females you will distinctly see two pistils at the branch "joints", or "nodes" as they're called. You will generally see this difference within 10 days after moving into this flowering stage light period. You want female marijuana plants (sensimilla) only - high in THC, low (to no) seeds. <LI done15="5" done11="5" itxtvisited="1" done6="1" done24="1">Step 2 Male plants MALE OR FEMALE?: There's no better way to say it...the males have balls, or at least what appear to be balls ( staminate ), and the females have short, white hairs called pistils. When your plants are in the pre-bud stage, you have a small window of time that requires careful observation before you have to remove your males from the females. Not doing so will result in your males pollenn sacs (balls) opening, pollinating your females, and the very undesirable result of seeds in place of bud. As flowering continues, the female plants begin to develop the pistils at every internode, even on the side shoots. After a few more days, the branches really start to show flower development as second and third hairs begin to appear at the node sites. These hairs are the beginnings of the mature beautiful buds we all seek. If they were to catch wind of some pollen, the small hairs would retreat back into their sheath and begin to develop seeds. <LI done15="6" done11="6" itxtvisited="1" done6="2" done24="2">Step 3 Female plants Even an experienced grower may have difficulty sexing plants, and if you aren't completely sure at first, it's better to watch and wait before tossing your males. Occasionally you will get a hermaphrodite plant which contains both male and female parts, thereby pollinating itself and producing seeds. Generally you will not want this plant and it should be destroyed, or at the least you should remove it from your females. There's no way to accurately determine the sex of a marijuana plant until after flowering has begun. It's not until the plants begin to develop reproductive organs that there's anything to look at. After the induction of the critical photoperiod, which is usually around 12 hours of uninterrupted darkness each day, plants begin to grow differentiated primoria. The new growth may take several days to appear. Some strains continue to grow vegetatively for several days before they slow down and start to flower. Other strains shoot up in a quick growth spurt right after the induction of this light cycle. The sure sign of the beginning of flowering is a change in the phyllotaxy of the plant. New growth has offset (or alternate) internode pairs, rather than the opposite pairs which grow during vegetative development. <LI done15="7" done11="7" itxtvisited="1" done6="3" done24="3">Step 4 If you aren't sure yet, just be patient and persistent. The males will get to a point that unmistakably resembles balls, right before their pollen sacs open. Additionally, very often the males will sex earlier than the females. There are other sex indicators, such as plant branching and leaf disbursement, however these methods are unreliable. Good luck and happy growing!
I know we are going to have a ton of post of "old timers" who do not wait for the 12/12 cycle because it waste there time. But for the new guys, wait. Be sure. More females have been destroyed by guys who thought they new the sex than by the DEA. So here is some basic information on preflowers for those who don't want to follow some sound advice and wait for the flowring stage: 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.