Nico’s Nuggets: Sexing Plants

Hi Nico, My name is Aaron. I am a big fan of your articles… I am a rookie grower based out of the Bay Area. After deliberating whether or not I should obtain a medical marijuana card for a few months, I finally got one. Now that I have one, and have been able to enjoy all of its privileges, I have become interested in growing my own. But how do I sex my plants and know which ones are male and which are female?
Would you happen to have published any guides or know of any articles that instruct a person step-by-step on how to grow? Also, on a scale of one to ten (ten being the hardest level), what difficulty level would you rate growing marijuana? Thanks in advance. – Aaron via

Greetings, Aaron and thanks for reading! Congrats on your medical card – that was definitely the right decision. Anyone who lives in a medical or recreational state should exercise their rights and get legal, even if it’s just to support your state’s rights and help put an end to federal prohibition of cannabis.

As for your questions, I get these often and am happy to finally point out a few things for our readers. First of all, on scale of one to 10, growing cannabis is very easy – I’d say a two or three! Of course, growing good quality cannabis may ratchet that rating up a little bit more. I always tell people to remember that it is called weed for a reason – it will pretty much grow anywhere! Cannabis is a string and durable plant. How well it grows, however, depends on you. But do not be afraid to grow cannabis – it is easy, fun and great Zen time.

As for sexing your plants, let’s first start with some basics for those out there who are unfamiliar with the topic. Cannabis plants, when grown from regular (non-feminized) seeds, will be either a male or female plant. Seeds generally germinate in a 50-50 male-to-female ratio, so in a pack of 10 seeds, expect to get five females. Female plants are the ones that most growers want as they produce the flowers we smoke. Male plants are only interesting to breeders who wish to collect and use their pollen in crossbreeding (hybridization) projects. Male plants do not make traditional flowers for smoking.

The problem that arises here is that growers need to remove the male plants from their gardens early on, so that pollen will not be released within the garden. Should this occur, the pollen can get onto the female flowers and cause them to form seeds. And no one likes seeds in their buds.

The best way to determine the sex of your plants without triggering the flowering phase is to look for “pre-flowers” on the plants. These pre-flowers will grow at the internodes, the point where branches meet the primary stem or shoots. Pre-flowers will begin to show around week four of growth – however, this does not take into account rooting times, so if you had a long germination and/or rooting period with seeds, you may not see pre-flowers until closer to week six. At this time, cannabis plants will begin to exhibit calyxes at internodes. If you do not see pre-flowers near the main stem, move outward on the branches and examine there. If still nothing, wait another week.

Male flowers, or staminate, will have a calyx (roundish growth) that is raised on a short, tiny stem. Female pre-flowers will have the calyx closer to the internode with little or no stem growth in the node. Use a small magnifier to help determine the structure of the pre-flowers. If the plants are close to the end of their vegetative cycle, other male indicators will be the height of the plant itself, the loose stacking of branches and pod-like sacs or tiny white flowers forming on branches.

Once a male plant shows a pre-flower, it will be less than two weeks before it begins openly pollinating, so upon sexing a plant males should be immediately removed. Also, remember that clones generally do not need to be sexed as they carry the same genetic makeup of their parent. If your clone was from a female plant (which is most likely the case if you purchased it from a dispensary) the clone will grow to be a female plant as well, so no need to worry.

As a side note, and since you asked… There are plenty of excellent grow guides out there that describe how to grow cannabis in great detail. Keep in mind a complete guide will be quite lengthy as there are a lot of subjects to cover. Many are sold on this website at the High Times Headshop. My personal favorite is an instructional, full-length DVD entitled Nico Escondido’s Grow Like a Pro! However, I would also like to point out to our readers that nearly every question one might come up with has, at one time or another, been covered on this very website by either myself or one of my colleagues. Using the search function on this site is a great way to access these archived articles, which cover every aspect of growing from seed to harvest. And soon we hope to re-organize the site even better so that all your grow needs are easily found in a single place, sortable by topic and author. So stay tuned and stay well, amigos!

Thanks for reading everyone and remember: Grow… And help the world grow, too!

Got questions? Email ’em over to Nico at and be sure to put “Nico’s Nuggets” in the subject line!
1 comment
  1. I have an existing female I have three new seeds I want to start any suggestions so I don’t accidentally pollinate

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