How to tell your Female Marijuana plants from the Male

The following series of photos are tracking the growth of only a few seedlings as the rest of the main crop are primarily clones from White Widow and Northern Light Mothers. Seedlings take a lot of time and care to establish a good healthy mature female. Acquiring the best seeds to grow for your particular environment and use is important in order to establish a great crop from which to clone.

If your goal is to generate more plants, growing from seed is the hard way to go. The seedlings in the next photos still must be sexed and then established in hydro-tubs with Geolite.


Once the sponge seedling has been popped into the Rockwool 4"x4" cube, the light cycle is set at 20/4 or twenty hours of light, four hours of dark.

Day#15 of 20/4 light cycle



The seedlings are now up over the Rockwool 5-6 inches. Began fertilizing with General Hydroponics 1/2strength for all purpose foliage stage. The plants have been watered sparingly every 2 days to make sure the Rockwool remains moist. Leave 1/4inch water in bottom of tray to insure the cubes do not dry out.

Another advantage of using the sponges inside the Rockwool cube is that they continue to draw water.

Day#18 of 20/4 cycle



Three days later, this photo of same seedlings shows good development of 2nd set of leaves and strong stems are developing well.

They are still at 2 feet from HPS 450 lamps. The room temperature is a little warm at 82* and 60% humidity, however the outside temperature is 95*.

By the time these seedlings are around 25 days old, they will be going to a 12/12 light cycle or 12 hours of light and 12 hours of dark to begin flowering the entire room. Shortly after beginning the 12/12 cycle, the plants can be sexed.

Day#21 of20/4 light



The seedlings are still on 20/4 light cycle. The growth is now at 8-10 inches with multiple sets of leaves. The young plants are developing very well with strong stems and will begin to show gender shortly.

When you are growing with a specific strain of bud in mind, it is important to be more radical in the removal of questionable gender plants. It does not take much for a sneaky lone male to pollinate your stock of Mother plants. If you are not concerned about seedy bud and lots of male plants, than this will not be a problem. In all likelihood, if you are procuring a specific type of seed, you will want to be very particular about what you allow to grow.

Some growers report that plant size is a good indicator of sex that females are shorter and branchier than males. The males tend to have fewer leaves near the top and females have more leaves surrounding the flowers.

With all the different varieties grown today, there are NO specific characteristics on the plant that will with 100% certainty, identify a male or female other than the developing flower itself. You just have to ride out the first few days of the flowering cycle to tell if your seedlings are girls or boys.



At this PREFLORAL NODE [intersection], the identifying flowers will begin to develop. The close up of seedling shows site where development of male or female traits will begin.



The tallest of the seedlings is now 22" tall. The plant is 36 days old and after 9 days in the 12/12 light cycle, is beginning to flower.

The lamps have been raised, keeping the plants 2' away. There is a very healthy root system developing beyond the bottom of the Rockwool cube so if this is a female, she will need to be set on the Geolite rocks fairly soon.

As the new plant develops, the number of leaves in each in each pattern will change. The 1st set has 1 leaf, the 2nd set has 3 leaves, the 3rd set has 5 leaves, the 4th set has 7 leaves, the 5th set has 9 leaves. This is a GENERAL guideline.


The number of leaves in a pattern may repeat themselves depending upon the type of strain and environmental factors.

The reason it is important to track the number of leaves in a pattern, relates to sexing the plant. Before the start of flowering, the leaf arrangement reverses and the number of leaflets per leaf will decrease until a single leaf appears by each set of the pistillate calyx.

This is a close up of the same seedling in the previous photo. The pistillate flowers are beginning to develop in the node[intersection]. The thin hairs that are protruding from the pistillate are becoming visible. They appear as a matching pair on either side of the main stem where the leaves develop. Two thin hairs will emerge from each swollen pistillate.

Great news Dad it's a GIRL!!

This second seedling is about 12" tall and the grower suspects the little devil is a male. After years of doing this, he would eliminate this plant now so there is no sneak attack of pollen. However for the sake of really good identifying photos, he is letting the plant develop past the STAMINATE PRIMORDIA which are the claw like male growth which appears before the staminate or male flower.


This is a closer view of where the male traits are beginning to develop. A magnifying glass enables the grower to see that this is indeed a male.

The Staminate flower is beginning to form behind the node, just above the PETIOLE [the shoot off the main stem that connects the leaf to the plant].

The male flower is more easily identified by what it doesn't show you the 2 tiny white hairs that emerge from the pistillate calyx. These develop very early on after the light cycle is cut back to 12/12.

The dreaded "Three Ball Cluster", which is confirmation of a male plant. The older Marijuana Gurus likened these to pawnbroker balls.



Staminate floral bud the tiny pollen producing flower will emerge from here.

Generally, the male flower will mature just before the female. This allows the male to produce the powdery pollen that when transferred to the fine white hairs protruding from the pistillate calyx on the female, will cause seed growth in the bud.

Anything at all will carry the pollen to the female air movement, hands and clothes, the cat's ass...etc. If a mature male surprises you and has opening flowers, bag it gently from the top and remove from the grow room.

Before controlling the crop with clone regeneration, it was amazing to see how clever nature is in smuggling those boys into the mix.

Above photo close up of mature female with floral clumps along the stem. The white hairs are also clearly visible. The important trait to observe is the pronounced pistillate calyx. The calyx is actually the ovary where seed development would begin if this plant had been fertilized.

The pistillate calyx will begin to develop shortly after the light cycle is cut to 12/12. This is actually the first and best identifier of sex early on.

This photo is the now mature female seedling from the beginning of this chapter. She is now 7 weeks old and is in day 23 of the 12/12 light cycle. She has excellent bud development in the top 12" of the plant and overall height is 3 feet. The original Rockwool cube is set in Geolite rock in an 8" container.

Normally, growers do not let a plant mature without any pruning, however to follow the incredibly rapid growth of a seedling to bud stage with no intervention, the plant in the previous photo was not pruned.

After the harvest, the plant will be cut down to around 10" and transplanted into a grow tub for regeneration into the next harvest cycle.

Day 12 of 12/12 cycle


MALE FEMALE

Male plant stripped of leaves to see male flower [staminate], unobstructed. Female plant stripped of most of leaves to see pistillate calyx.

After the light cycle is reduced to 12/12, the first sign of flowering is the pod or primordia behind the node in the male plant. The ish female GENERALLY indicates sex with the emergence of the 2 white hairs.


Until you have been through several crops, the identifying process is not simple. Many growers have thrown out the wrong baby in the early stages and probably this phenomena is responsible for many of the so called "hermaphrodites" as a result of undetected male plants remaining in the grow room.

Before you order those expensive pot seeds run a couple of "ditchweed" seeds through a cycle so you can accurately identify male and female plants.