If you’re starting out on your weed-growing adventures right now, there are a few things you should bear in mind in order to make your early attempts as hassle-free as possible. We’ve all made rookie mistakes when growing cannabis, and you’ll be no exception, but if you follow this guide you can avoid the most common ones.

Remember your plants are delicate, fragile beings, even if they are also incredibly resilient and can cope with a lot of trauma. Treat them like you’d wish to be treated, and make a good impression on them – so that they’ll return the favor and yield the goods at harvest time!

Waterboarding Is Torture!

Over-watering is one of the biggest mistakes new growers make. Much of the time, beginner growers opt for soil over hydroponic techniques, which is great as it’s simple, forgiving and hassle-free. But soil can absorb and store a lot of water, which can become a problem for your roots. Roots need air to breathe, so if you pour gallons of water down there, you’re essentially drowning them! When using soil, aim to keep your root zone moist but not wet.

With hydroponic systems, you must manage the water in a way that ensures that the roots can breathe. For systems that involve keeping the roots in water for long periods, like deep water culture, it’s essential to have an air bubbler in your tank so that oxygen gets to the roots.

Don’t Be A Feeder

Over-feeding is another cardinal sin that most novice growers commit. Nutrients make plants get big and strong, so the more nutrients the better, right? Wrong! In fact, it’s pretty similar to vitamins for humans – in the right doses, they’ll work wonders for growth, development and overall health. But if you take too much, many vitamins can cause serious health problems.

When they’re in your diet, you could eat too much of a vitamin for an extended time without realizing, and problems will only start to arise after levels build up enough. In exactly the same way, if you repeatedly feed your plants too much nitrogen or magnesium or sulphur, problems will become apparent after a while.

The “right” amount of nutrients can be very hard to determine, and even expert growers can get it wrong. Different strains have different requirements, and changes in environment can make even the same strain take in nutrients differently. For sure, do not exceed the stated dose for your chosen nutrients, and stick to the lower end until you are certain they can handle more.

In certain types of soil, you might not need to add any fertilizers to the feed for the first few weeks, as plenty of soil mixes are prefertilized. Pay attention to soil manufacturers’ advice too! Disregarding their instructions could quickly lead to problems.

Let There Be Night!

If you are growing cannabis, you should certainly know that the plant needs long nights (at least 12 hours of darkness) to flower. But even though most new growers know this, it’s surprising how many still manage to make the rookie mistake of interrupting their plants’ precious sleep.

Maybe you just want to show your friend your new project and you just can’t wait. Or maybe you’ve just forgotten that LED light on that appliance in the corner of your grow room, or you haven’t sealed the entrance properly. But whatever the reason, you’ve just caused your plants some pretty severe stress, which could result in slow growth, lower yields, or worst of all – hermaphrodites.

Yes, light stress at night, even if it’s just for a minute or two, or from a light that isn’t that bright, can cause severe stress to plants. One of the most common consequences is the growth of mutant male flowers on your female plants. Of course, male flowers = pollen = fertilized female flowers = seeds! If you end up with hermaphrodites, your entire harvest could be full of seeded bud. So just make sure that when those lights go off, they stay off for 12 whole hours, with no exceptions!

Phuck! pH Phroblems…

Again, most new growers should know about pH, but it’s surprising how many seem to think that it doesn’t apply to them, or it’s not that important. Sure, the importance of rigorously checking your pH does depend a lot on the type of system that you use. But no matter what system you use, it’s a very good idea to routinely incorporate some form of pH testing to ensure that you are staying with the correct range.

Generally, soil-based systems with organic nutrients don’t need rigorous pH control. One of the primary aspects of organic growing is building up the bacteria and fungi in the root zone – and when healthy and thriving, your soil microbes do the work of balancing pH for you! Adding acid to your water to reduce pH may even harm those microbes.

However, it’s a good idea to check soil or runoff pH to make sure that everything is in balance. If it’s much lower or higher than the ideal soil pH of 6.0 – 6.5, your soil may need an additive to rebalance it. You can add additives such as oyster shell lime to raise pH or elemental sulfur to lower it, without straying away from organic principles.

On the other hand, when working with mineral, inorganic nutrients, especially in hydroponic systems, pH control becomes more of a pressing issue. Soil acts as a kind of buffer, so even if your pH is a little off, it will take a while to cause problems. But in hydroponic systems there is no buffer, and if your pH is off, it can very quickly cause visible problems. Basically, pH has to be within the correct range (5.5 – 6.2 in hydro systems) for the plant to take up essential nutrients.

Blowing Too Hot And Too Cold

Temperature control is key to growing healthy, happy cannabis plants. You can easily avoid the common rookie mistakes of letting your room get too hot or too cold by following some basic steps. Your plants ideally need to stay in the range of 24–28 C (75–82.5 F) in the daytime and 16–21 C (61–70 F) at night, for optimum flower development and trichome/terpene production.

If you’re growing indoors in a hot country, try to get hold of a cool light, such as an LED, instead of a hot light like an HPS. That should make your energy expenditure a little lower – otherwise, you can opt to use air-conditioning, but that can be costly in energy terms.

In winter, or in generally cold countries, indoor growers may be better off using hotter lights in many cases, as cold LEDs won’t warm the room as much and external heating may be required.

One major consideration is the difference between daytime and nightime temps. A difference bigger than 10 C / 18 F may cause stress to your plants, as well as opening your room up to the possibility of excessively high humidity.

Don’t Sweat It!

On that note, you have to make sure your relative humidity stays within the correct range. This can be hard to achieve, but one of the biggest rookie mistakes is not thinking about it at all!

For optimum growth, relative humidity should be in the range of 40–70% during vegetative growth, and 40–60% during flowering. If you allow RH to become too high, it can lead to mold, mildew and fungus attacking and taking hold. It can also interfere with the plants’ natural process of absorbing water through the roots and releasing it through the tiny holes in the leaves called stomata. When RH goes above about 80%, the stomata release less water, which may slow growth!

If RH goes too low, it can actually cause the stomata to close entirely, which will certainly slow growth if it happens consistently.

Manage your relative humidity by controlling your temperature range and your airflow. If you have too much of a temperature drop at nighttime, your RH can rapidly rise to unhealthy levels, as cool air holds less water vapor than hot air, so it reaches saturation point quicker. Make sure you vent properly to replace any moist air with dry, fresh air, and if cold temperatures are a serious problem, think about heating your plants.

No, A Normal Light Bulb Won’t Work…

It’s astonishing how many people we’ve encountered over the years that seem convinced that they’ll successfully grow cannabis under a 90W incandescent bulb. Clue: you won’t. If you’re growing indoors, you need a very powerful, bright light to replace the incredible power of the sun! By all means, try… but we can tell you right now you’ll fail miserably.

On that same note – no, don’t use regular Miracle-Gro from your local home and garden store to grow cannabis! You won’t get a good result – if nothing else, your crop will taste like utter crap. We’re speaking from first-hand experience here, having met several hapless home growers who have refused to listen to the sage advice of their elders and betters. In fact, it used to be so common it was a running joke in some circles.

Even more hilariously, it turns out that Miracle-Gro has now actually begun investing in the cannabis industry – last year it bought General Hydroponics and Gavita! Alanis Morissette: if you’re reading, that’s ironic…

Anyway! Thus concludes our guide to avoiding rookie mistakes when growing cannabis. We hope you enjoyed reading – and if you have any other questions please let us know in the comments!