The Most Common Mistakes When Growing Marijuana at Home

If you’re a beginner who is just getting started on your first home grow setup, we’ve got some bad news for you: you are going to make mistakes! But don’t be discouraged. Mistakes are inevitable but invaluable since these will give you the information you can use to fine-tune your setup. Also, experiencing these mistakes first-hand will give you a better “feel” for growing. For example, some growers find that the recommended amount on some fertilizer brands is too much. Using too much fertilizer can lead to “nutrient burn” that makes the tips of your plant’s leaves dry up. Most of the time, getting the right amount of fertilizer requires a bit of trial and error.  The results can be different for every grower.

It’s ok to make mistakes, but what you don’t want is to make mistakes big enough to wipe out your plants and thus, your investment. To help you minimize risk so you can enjoy your growing journey, we’ve listed some of the most common mistakes inexperienced growers usually commit. While there are a lot of other problems that you may encounter as a beginner, we’ll mention only the ones that are not so obvious.       

1. Buying cheap seeds 

“What, $77 for just 4 seeds?!” If it’s your first time shopping for seeds, some of the prices may surprise you. You may also think that it’s ok to go with cheaper seeds or buy on that sketchy-looking website with amazingly low prices. Word of advice: don’t skimp on seeds. 

Some seeds are expensive for a good reason: breeders have worked long and hard to bring out the best qualities of that strain. Additionally, you can grow that strain again and again for as long as you like, once you learn how to clone or grow your own seeds. 

Some cheap seed packs also have males in them. Males are only useful for growing seeds, but you won’t get smokable flowers out of them. They can also pollinate your female plants and once that happens, you can say goodbye to those buds that you’re looking forward to harvesting.

The germination rate on cheap seed packs is also often low. Even if you think you got a good deal by paying only $20 for 10 seeds, if only 2 of them germinate and the other happens to be male, then you got ripped off instead!

To get the most bang out of your buck, you need to get your seeds only from reputable companies that work with top breeders in the country. One way to tell if you’re buying from a good seller is if you can see a list of breeders they work with on their website. Another thing to look out for would be the seed’s genetic history and detailed information on its strain profile.  

2. Using cheap soil

“Plants grow in soil, amirite?” While that is true, regular garden soil just doesn’t cut it since you can’t be sure if it contains any harmful chemicals or fungi. Using a good growing medium will certainly make it easier for you to grow your plant, and for beginners, it is usually soil. 

Good soil for growing marijuana should be able to:

  • Hold the right amount of water
  • Drain excess water
  • Allow enough oxygen to get to the roots

Some growers like to make their own soil since it’s just made out of natural ingredients like compost, worm castings, sandy loam, etc. but honestly, it can be too much effort for a beginner. It’s also possible that you can mess up the ratio of the soil components so we recommend that you just buy ready-made potted soil like FoxFarm’s Ocean Forest Potting Soil. This is definitely the way to go if you just want to see your plant grow healthy as soon as possible.

3. Transplanting too early or too late

Transplanting your young cannabis plant at the right time is essential since its roots will need room to grow. At the same time, you don’t want to transplant it when the roots are still fragile and vulnerable. 

You may think “Why not just plant them in a big pot from the start?”. This is hardly ideal since the seedling’s small roots will have difficulty absorbing water if there’s too much soil around it. The excess moisture can also settle in the soil and cause root rot.   

How would you know if your plant’s roots are already getting cramped in its seedling cup? Actually, you do not want to get to that point since your plant will already be stressed by then. What you want to do is estimate the right time to transplant it. Here are some key indicators:

  • The plant already has a set of leaves as wide as its container
  • It usually takes only 7-10 days for a seedling’s roots to be ready
  • Some parts of the roots are no longer white and are starting to show discoloration

Keep in mind that every time you transplant, you are stressing the plant. Some growers transplant only once, some twice. Don’t let this discourage you from doing transplanting, you’ll get better results with it than just planting in a big pot from the get-go, if you do it correctly.  

4. Overfeeding

Most beginners think that more is is better when it comes to nutrients. It is not. As you gain more growing experience, you’ll notice that every aspect of caring for your plant is more about finding the right balance. This is particularly true for the amount of fertilizer that you use.

Overfeeding your plant with fertilizer can disrupt its water intake and cause “nutrient-burn” since it makes the tips of your plant’s leaves to curl upward and appear “burnt”. If it curls downward, this could mean that it is getting too much nitrogen

One thing to keep in mind is that the more light your plant gets, the more nutrients it is able to process. This means that plants that don’t get enough light won’t be able to process as much nutrients and this can also lead to nutrient burn.   

One way to fix nutrient burn on potted cannabis plants would be to add properly pH’d water and just wait for the plant to use up the nutrients. However, be careful not to overwater your plant since that will also cause problems. 

5. Over-watering

You may also think that there’s no such thing as “too much water” for a plant. Unfortunately, it is and too much water or watering too frequently can drown the roots and deprive it of oxygen. 

Watering a cannabis plant is not as simple, you’ll have to figure out by experience how much and how frequent your plant needs water. If its leaves are quite firm and drooping downward, it means it’s getting too much water. In worse cases, the leaves will start to turn yellow due to nutrient problems. 

Over-watering problems can be remedied by making sure that your plant is planted in good soil. If you chose to buy good potting soil instead of mixing your own, this will not likely be a problem. Also, make sure that the plant’s pot has adequate drainage that can keep the soil moist but not water-logged.

6. Over-pruning

Leaves are a plant’s “solar panels”, they use it to receive light so it can process the nutrients you’re feeding it. The idea behind pruning is that you’re removing unnecessary parts of the plant so they won’t use up energy and resources. 

When pruning, what you want to remove is unhealthy parts like wilted stalks and leaves, as well as parts that won’t receive much sunlight. You also want to prune to let air circulate under the canopy, but you want all the branches to still have some support. There are a number of ways to prune but usually, the easiest style for beginners is the “lollipop” style where the lower branches are pruned. You may need to put support on the plant’s stem after pruning to prevent the weight on top from bending it.

Pruning will cause your plant stress, so don’t prune it while it is flowering. The best time to prune it would be around a week before it flowers so it has time to recover from the stress. 

7. Mismanaging water pH

Your plant can only absorb nutrients if the pH levels of its soil and the water that you use is correct. Cannabis plants thrive in soil that is slightly acidic, which is around 6.0-7.0 pH. For soil-less setups, its usually around 5.5 – 6.5 pH.

pH levels are usually tested using pH strips or drops. But in our opinion, digital pH pens like the 7Pros pH meter are more accurate and easier to use. They’re not even expensive, so it’s really a no-brainer that you should get one.

8. Putting the light source too close

Perhaps you are growing indoors and did not anticipate that your plants would grow so big. Or maybe you just heard that cannabis plants grow bigger with more light. Again, it’s all about balance. Even if you’re using lighting that does not emit much heat like LED lamps, you should still put ample distance between the plant and your light source. 

One sign that your plant is getting too much light is if its leaves are starting to point upward. In worse cases, they will turn yellow. You may also notice that the ones closest to the light are the most discolored. There’s really no other way to fix this except to move your light source away. If that’s not possible, then you’ll have to bend your plant slightly away from it.

If you are using lighting that emits heat, your plants may also be suffering from heat stress. To fix this, you need to lower the output of your light source. You can also make the environment cooler, but it won’t be energy efficient. This is it’s a good idea to figure out the kind of lighting that will best suit your setup beforehand.   

9. Not removing males

It’s highly unlikely that you’ll grow any male plants if you bought a pack of feminized seeds. But in the off chance that you do grow one, you should remove it immediately. Males can pollinate your female plants and make them grow seeds instead of buds. 

The problem is that it can be difficult to tell the males and the females apart until they begin to flower. However, by the time that you can already see the difference, the males are already ready to pollinate. 

Fortunately, the technology involved in identifying the sex of pre-flowering cannabis plants is getting better and cheaper. Now there are test kits like Phylos’ plant sex test that can be used on seedlings just 7 days after germination. 

But if you’re growing just one or two plants, this kind of test may be a bit too much. If testing is not an option for you, you can either try a visual inspection of their nodes or by inducing flowering on a cutting from the plant. 

In most cases, the pre-flowers appear at the nodes of male plants at about 3-4 weeks and female plants at 4-6 weeks old. You’ll need a magnifying glass to see the subtle differences between the male and the female’s pre-flowers. Female pre-flowers look like tiny bracts with hair-like stigma peeking out while the male’s look like small, round balls at the nodes. 

You can also use a cutting from your main plant and have it reveal its sex. Isolate it and induce it to flower by exposing it to 12 hours of light/darkness. The cutting will have the same sex as its mother plant. 

Take note that a cannabis plant can also turn into a hermaphrodite due to factors like stress and nutrient deficiency. This means it can be both male and female and this can seriously affect the quality of your yield.   

10. Harvesting too soon 

The right time to harvest is kind of arbitrary and depends on what the grower wants. The amount and kind of cannabinoids present in the bud, as well as its effects, can change depending on how mature you want it to be. However, there are 3 factors that can guide your decision on when to harvest:

    • The color of the stigma – These are the white, hair-like strands on the bud. When these start to curl and darken into orange, it is a good indicator that the bud is ready to harvest.
    • The color of the trichomes – These are the smaller hair-like things that have a round end and look like a blanket of frost all over the buds. You can only see these with a microscope. Generally, the bud is most potent with THC or CBD when the trichomes appear milky white. When these turn amber, it means the THC has degraded into CBN. By then, the bud will have more of a calming, sedative effect. 
    • The breeder’s recommended harvest time – This is just a rough estimate since the way you grew the plant will have a huge impact on how the buds mature.

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