The Growth Stages of the Marijuana Plant

The growth stages of a marijuana plant’s life is essential knowledge to anyone who wants to cultivate it. If you want a healthy, resilient plant that will give you a good yield, you have to be proactive rather than reactive in caring for it. While there are now countless strains of cannabis, each with its own nuances, they will all go through the same stages of growth.

Once you’re familiar with what goes on in your plant at each stage, you’ll be able to anticipate the needs of your plant instead of just troubleshooting problems as they come. 

How many growth stages are there? 

You may be confused by the information you’ll get online. Some will say there are 7 stages, some say there are only 3. For our discussion, we will base the number of stages on the significant changes that happen to the plant that will require you to adjust the kind of care you give to it.  

1. Seed 

Wikimedia Commons: Omar Hoftun

Some also call this the “germination stage”. Basically what you need to do is make the seed sprout and transplant it into a growing medium. Although it may sound simple, new growers are often frustrated when they find that some of their seeds aren’t sprouting, or if the sprout died after transplanting. 

If you bought your seeds from a reputable source, you no longer need to pick out quality seeds to germinate. It’s likely that 90 to 100% of them will sprout if you germinate them properly. But if you’re stuck using a bunch of cheap seeds, then you’ll need to choose only those that are hard and dry. Often they will be brown to light brown in color. The ones that are soft and green are too young to germinate.     

How to germinate using the paper towel method

The easiest way to germinate your seeds is by using the wet paper towel method. The idea behind this is just to let the seeds rest enclosed in a soft, damp material that they won’t stick to. What most growers like to do is to dampen some paper towels, around 2 layers, just enough so that it doesn’t drip. Place this on a plate, then place the seeds on it with around 2 inches distance from each other. Gently cover it with an additional 2 layers of damp paper towels. Place another plate on top with its bottom facing up to create a dark, dome-like space in between. Keep the temperature warm, around 70-90F.  

Check on them after a day. You may notice that some seeds already have a white sprout growing out of them. This is the taproot. Take the ones that already have half a centimeter of taproot and place them in your growing medium with the taproot into the soil. No need to bury the whole sprout, the taproot will grow into the ground within a few days. 

Take note that some seeds may take longer to sprout. The whole stage should just take 5 to 10 days so if you have some seeds that haven’t sprouted towards the end, safe to say that those are duds.

2. Seedling (2-3 weeks)

Your plant is still very vulnerable at this stage so you need to protect it from pests, extreme temperatures, etc. You’d want to cover your seedling with some kind of transparent dome that will retain moisture but still allow some air in. Some growers like to use pet bottles that have been cut in half. Poke some holes at the bottom of that and it’s ready to cover your seedling.

Overwatering

One common mistake beginners make is to overwater their seedlings. Admittedly, getting the right amount of water and frequency of watering can be tricky. Just keep in mind that the idea is to put just enough water in the soil for the roots to absorb but not drown in it. The roots need access to oxygen so your plant’s pot should be able to drain excess water but hold just enough so that the soil won’t dry out. 

You should also water in small amounts so the soil won’t get water-logged. If the soil’s surface is moist, you can probably hold off on the water. If it’s wet and damp, then you’ve put too much water. If the soil is already separating from the cup, then its already drying out. 

Nutrients and transplanting

When the seedling has grown 3-4 sets of true leaves, they are ready for plant food. Luckily, you need not bother with the right combination of nitrogen, phosphorous, and potassium since you can easily buy fertilizer that is already specially formulated for each stage of your plant’s life. For example, Reefertilizer’s Complete Cannabis Nutrient Kit has a Start, Grow, and Bloom pack for the seedling, vegetative, and flowering stages respectively. Depending on the kind or brand of potting soil you are using, you may not need to use the Start pack anymore.

Around this time the plants are likely ready to be transplanted. This depends on the size of the cup they’ve been planted in. You don’t want the roots to get cramped in the pot. Check out our article on The Most Common Mistakes When Growing Marijuana at Home to know when it’s time to transplant.

3. Vegetative (3-16 weeks)

This is the stage where you want to maximize the growth of your plant. Chances are, you have an autoflowering plant since these are more manageable to grow at home. Autoflowering plants can do without the light cycles so some growers prefer to keep the light on for 24 hours, claiming that this maximizes plant growth. Others say that several hours of dark can give the plant time to recover. This is largely a grower’s choice and it’s up to you which one fits your growing setup better.

The first thing you want to do at this stage would be to identify any male plants. If you bought feminized seeds then you know that males are of no use if you just want to grow for harvesting since they’re only good for growing seeds. To learn how to differentiate males from the females, please check out the other article that we mentioned earlier.

Pruning and training

This is also the time when you should be training your plant. It’s going to grow big and in the shape of a Christmas tree. This is the cannabis plant’s natural shape and you’ll want to train it for several reasons: 

  • So that all of the plant’s parts can get enough light.
  • You can maximize space.
  • Trimming the unnecessary parts will help the plant put its energy and resources to better use.

Training is critical for getting a better yield. There are a lot of techniques involved in training like pruning, Scrog (screen of green), Low-stress training, etc. and the technique that you will use will depend on your setup. This puts a bit of stress on your plant so do this a week before it enters the flowering stage at the very latest.

4. Flowering (8-11 weeks)

This is also referred to as the “bloom” phase, as you may see on some fertilizer packs. At this time, the plant redirects all of its energy to making those sweet buds you’re waiting to harvest. If you have an autoflowering plant, it will automatically enter this stage regardless of the light cycle. But if you have a photoperiod one, you’ll need to induce it by restricting light cycles to 12 hours light and dark periods.

The cola, or bud, will grow at the end of the larger branches. It’s likely the biggest ones will occur at the top or wherever it is that gets a lot of light. This will put some weight on the branch. Make sure that you’ve properly trained and supported your plant to anticipate this. 

Monitoring your plant closely

Most likely you’re already using the specially formulated “bloom” fertilizer at this point, which is ok. One thing to keep in mind though, flowering cannabis plants use up a lot of phosphorus and potassium. Some growers like to put additional PK 13/14 as extra stimulation for flower development. These can give you denser and more compact buds. 

While waiting for your buds to mature, you need to closely monitor the temperature, humidity, airflow, and nutrient levels. These factors make a significant impact on the final quality of the bud. Also, be extra vigilant of mildew and mold since these only become noticeable after spreading internally on the bud. These often show as an odd, yellow-colored sugar leaf sticking out from the middle of a mature bud. If you can pull it out easily, it means that bud is already badly infected.

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