What? Of course temp and light have roles in determinimg plant sex as0
Whenever people start a sentence with the phrase, "I don't think" that means:
a) they aren't really sure
b )they normally don't think but sometimes they do
c) everything that follows the clause is suspect (this is correct)
@Oldchucky -- OC, next you're going to say you don't believe in John Stuart Mill's argument about free will in humans? Everything isn't determined in either plants or animals or people because the environment dictates a lot of what will happen; how much you have to eat and what you eat and how cold/hot you are determines whether you live or die. Would you say that plant container size and shape has something to do with whether plants become male or female (at least 4" container height is recommended? ILGM has a whole section on 'helping' ensure plants become female. Read the following (from some expert chimps with typewriters) and see if any of this changes your mind....@notfrankster can also chime in ..... You could also do some field research here and wander around seeing how many 'males' present themselves as 'females'
Environmental Factors Influence Cannabis Seed Gender
Just as environmental factors will affect your
cannabis plant yields, environmental factors will also influence the gender of your cannabis seedlings. If you don’t have a good grip on your growing environment, maybe you should postpone germinating that $75 seed you just bought.
Think of the cannabis plant choosing the male gender as a defensive mechanism in certain circumstances. Aside from being genetically predisposed to growing as a male, in several instances a plant could choose to be a male due to a stressful environment – not enough water, too much heat, or maybe a pest infestation. A male would pollinate nearby females and increase chances of survival from whatever is causing the cannabis plant stress.
These Specific Weeks During Vegetative Growth Are Critical For Ensuring Cannabis Plants Grow Into Females
The third and fourth week of the vegetative phase of growth are the most unforgiving weeks when it comes to determining your cannabis plant’s sex (gender). Take extra care of your plants during these weeks and make sure these aren’t the weeks you decide to leave the plants home alone for a couple days while you take a long weekend at the shore house!
If you’re planning to use any of the tips below to ensure female cannabis plant growth, you may want to begin enacting them ahead of this crucial growing period, so by the nutrient levels and environmental changes have time to take effect on your plants. Some of the tips are easy to enact right away, but with nutrients it could take a few days.
This
study found cannabis seedlings “choose” a gender by the time the fourth node is grown. So also take this into consideration when you’re trying to influence your cannabis plants’ gender. You want to influence those plants before the gender is decided.
Increased Nitrogen Levels Encourage Cannabis Seedlings To Grow Into Female Plants
Keep in mind that you don’t want to begin
feeding nutrients to your plants until they’ve entered the vegetative growth phase, or about two to three weeks of age. Once at that point, providing your plants with a good amount of Nitrogen will encourage it to grow as a female.
Of course the question on everyone’s mind is “what is a good amount of nitrogen?” and it’s hard to give a specific answer because the answer for you may not be the right answer for someone else growing with a different brand of soil that has a different amount of nitrogen within it.
With that said, remember that cannabis plants will basically tell you if they need more nitrogen or not, and you should be able to determine as much and act on it by the time you get to the critical weeks three to four of the vegetative phase, where any environmental stress will increase the odds of growing male plants.
Remember that lime green colored leaves usually means the plant can use more nitrogen, and dark green, shiny leaves usually means the plant is getting too much nitrogen.
Low Potassium Levels Encourage Cannabis Seedlings To Grow Into Female Plants
Keeping potassium levels low in your nutrient mix has also shown to encourage cannabis plants to grow as females. If the nutrient solution you’re using has a high level of potassium, you may want to consider making and using your own nutrient mixture with less potassium until you’re sure you’ve got females.
If you’re growing with organic compounds that are naturally rich in potassium, such as wood ash, it may not be the best environment for encouraging female plants. At a minimum make sure you take the nutrients in your organic soil into account and adjust accordingly for any additional nutrients you may be feeding.
Low Temperatures Encourage Cannabis Seedlings To Grow Into Female Plants
Keeping growing temperatures in a healthy range is already a big problem for a lot of growers. It’s also going to be a problem for those cannabis seedlings you’re hoping grow into female plants. Check out
my post on lowering temperature in your grow tent for a few tips on the subject.
If you want to encourage more female cannabis plant growth from seeds, keep your temperatures around 70 degrees Fahrenheit, with little fluctuation.
Seeds germinate best at 78 degrees Fahrenheit (25 degrees Celsius). But once they sprout, keep the temperature steady around 70 degrees. I know this is a big ask for some people but if you’re tired of growing 4 out of 5 males in a 5 seed pack (or worse), these are the tricks you need to focus on!
High Humidity Levels Encourage Cannabis Seedlings To Grow Into Female Plants
Increasing humidity levels will encourage more female plant growth. As you’re approaching those critical weeks during veg, try increasing your humidity to about 70 percent. I know this sounds crazy because you’re asking for mold or mildew at those humidity levels. But if you can get away with it for a couple weeks you’ll be golden. Keep an eye on your soil moisture levels when you do this because the increased humidity will dry out your soil faster, and dry soil is a cause of stress for cannabis plants!
More Blue Light Exposure Encourages Cannabis Seedlings To Grow Into Female Plants
Strong blue light is essential to cannabis plants during the vegetative phase, with a focus on the word “strong”. More blue light exposure will encourage those young cannabis plants to grow into female plants. So if you’re using low strength T5 tubes, perhaps focus on upping the power and increasing the blue spectrum quality with
a Metal Halide grow light fixture, or a
blue spectrum LED grow light.
If you have a grow light with two light modes, you’ll want to keep the red lights turned off during the vegetative phase. This is pretty basic and a lot of growers are already familiar with the concept of blue light spectrum being for the vegetative phase, and the full light spectrum (blue to far red) being used during flowering.
If you have a single mode grow light that includes red diodes, just focus on the other points in this post, or get a
dedicated blue spectrum grow light for the vegetative phase, if you’re willing to go that far.
Less Light Exposure Time Encourages Cannabis Seedlings To Grow Into Female Plants
I frequently hear of growers running 20 and 24 hour vegetative phase light cycles. There’s nothing wrong with that. But if you really want to encourage female plants, expert cannabis cultivator Jorge Cervantes recommends 14 hour veg light cycles to encourage young vegetative phase cannabis plants to grow into female plants.
Once you’re sure you’ve grown females, go ahead and increase that light exposure time again until you get to the flowering cycle, or until you harvest if you’re growing autoflowers.
But as you’re approaching those critical veg weeks three and four, you may want to consider decreasing your light exposure times to 14 hours per day. Switching back to 18 or 20 hours won’t hurt the plants as long as you’re in the vegetative phase of growth.
I don’t want to mislead, you can certainly grow female plants with 18 or 24 hour light cycles. But if you’re growing expensive unfeminized seeds and you want to encourage them to grow into female plants, consider temporarily reducing your light exposure as mentioned above.
What To Avoid When Trying To Grow Cannabis Seedlings Into Female Plants:
Environmental Stress
Environmental stresses of any kind will increase the odds of your precious cannabis seedling growing into a male plant. I refer you again to
my guide on increasing cannabis yields, because the very first section is a growing environment checklist for you to ensure you’re offering your plants an ideal growing environment.
List Of Environmental Stresses For Cannabis Plants:
- Under and over-watering
- Under and over-feeding
- Frequent temperature fluctuations
- Temperatures outside of recommended range for growing
- Mold, mildew, and pests
When you combine that with the tips offered in this post, your odds of growing your cannabis seedling into a female plant are much higher than if you had done nothing. I cringe reading the reviews for exotic cannabis seeds where people say every single seed in the order died or turned into a male plant. Sure, receiving a bad batch of seeds is a possibility, but you really have to wonder if the grower knew what they were doing in the first place!
