This photoperiod manipulation signals to the plant that it is time to start flowering whether the plant already has roots or not. Because clones are exact genetic copies of their parents, forcing a clone to flower separate from its parent will give you a clue regarding the specific gender of its parent. If a clone produces pollen, you know its parent is a male. Conversely, if the clone begins to flower (look for those pistils), you know its parent is female. Now you can remove all male parents leaving only the females behind to flower.
No pollen, no seeds, only happy girls and bountiful buds. Other things to look out for which may help you determine the sex of your cannabis plant include the plant’s height (males tend to be taller than females though much of this depends on the strain type, as well) and the size of the calyx, or the center-most part of a flower. If the calyx is large with a protruding white hair, it is likely female. On the other hand, if small and swollen with no hair, it’s likely a male. This distinction can be made before the plant begins flowering during a stage called “pre-flower.” However, it can be difficult for the naked eye to determine gender at this stage; a jeweler’s magnifying glass can help, though. Experienced cannabis growers understand the importance of separating male from female cannabis plants. With a little practice, many can catch and dispose of males long before they have the chance to pollinate females. Fortunately, even if you’re just starting the homegrown cultivation process, you can sex your plants before it’s too late, as well. Use these tips to predetermine the sex of your cannabis plants so that your girls will thrive unadulterated. Do you have tips for determining the sex of your cannabis plants?
Abby is a writer and founder of Cannabis Content, a marketplace designed to connect cannabis writers and creatives with businesses in the industry. She has been a professional cannabis writer since 2014 and regularly contributes to publications such as PotGuide and M&F Talent. She is also the Content Director at Fortuna Hemp, America’s leading feminized hemp seed bank. Cannabis Pre-Flowers: Identify Sex of a Plant as Early as 3 Weeks Old (with pics!) Table of Contents. Leaf Sample Testing (Bonus) – Identify sex in just 1-3 weeks from germination Male Pre-Flower Pics – Appears 3-4 weeks from germination Female Pre-Flower Pics – Appears 4-6 weeks from germination. Variability of Plant Sex (How to Increase Ratio of Female Plants) Example of Male and Female Cannabis Pre-Flowers. Wispy white hairs are a sure sign that you’re looking at female pre-flowers. How to Determine the Sex of a Young Cannabis Plant. What are cannabis “pre-flowers?” They are little versions of adult flowers that appear on your marijuana plants relatively early in the vegetative stage. When I first started growing weed, I learned (incorrectly) that there is no way to determine a cannabis plant’s sex until the flowering stage. But I’ve since learned that pre-flowers can reveal the plant’s sex while it’s still in the vegetative stage! Cannabis plants grow pre-flowers as young as 3-4 weeks from germination for male plants, and 4-6 weeks from germination for female plants. Cannabis Pre-Flowers Are Small Versions of Adult Flowers. Knowing the plant’s sex is helpful because most hobbyist cannabis growers would like to identify and remove male plants from the grow room early in the growing process. This is because only female plants make potent buds/flowers, while male cannabis plants make non-potent pollen sacs where female plants would grow buds. Additionally, female buds need to avoid pollen from male plants in order to make the highest quality cannabis ( sinsemilla or “no seeds”). Cannabis pre-flowers appear at the base of leaves when male plants are about 3-4 weeks old , and female plants are 4-6 weeks old . Even if you’re not 100% sure about every plant from looking at the pre-flowers, it’s nice to know which plants you need to watch closely and which are definitely female. However, if precision is very important… Chemical Leaf Tests Can Determine Sex & Potency for plants as young as 1-3 weeks. Chemical leaf testing is getting less expensive every day and can be used on cannabis seedlings with just a few sets of leaves to test for sex and future potency .
These tests only require a tiny amount of plant tissue (for example a small punch-out from a leaf, or a single cotyledon leaf), so it won’t hurt or slow down your seedlings to take a test sample!
In general, the tests are available for seedlings as young as 1-3 weeks.