10 Regrettable Mistakes To Avoid When Growing Cannabis

It pains me to watch people make the same mistakes over and over again. Of course, they seem obvious to anyone with experience – but more so they are avoidable, which is why I wrote this article for you.

Perhaps you’re stumbling out of the winter stupor feeling the sunshine on your face and remember your gardening dreams.

Maybe you’re inspired to plant some seeds and grow your first cannabis, be it high CBD “hemp” or high THC medicine, or something in between.

Or maybe you’ve grown before, but ready to nurture those plants into the giant giving trees you see in the pictures (yes, it’s real).

Whatever your reasons, Spring is marching forward and the time is approaching. 

If that’s you. If you want to grow with success – well then here is my gift to you, the top mistakes everyone makes when they grow cannabis without reading the user manual! (okay dude?). 

Okay, all jokes aside, let’s grow some beautiful medicine.


1. Planting In the Wrong Location

Location, location, location. Cannabis plants have favorite conditions where they do best and your role is to plant them in places where they can thrive. 

Here’s 4 common mistakes about choosing a growing location.

Not Enough Sun

People often trade security & safety of their plants being hidden over getting them in the direct sunlight. Lack of enough sunlight will cascade into a number of problems down the line, especially in yield. Plants without enough sun will not grow well, they’ll look stunted and “leggy” as they reach for whatever sunlight they can find.

Lazy Soil

Well drained & nutrient rich soil is what cannabis needs to grow well. Sure, your plant might grow anywhere… but unless you are deliberately setting up teeny tiny plants for your garden Gnomes, I recommend you step up your soil game. 

Anything less and your plants will suffer. Cannabis is a “heavy feeder”. Some of the best plants I’ve seen & grown have been the ones growing right in the compost pile. No kidding. Plants in nutrient deficient soil will have many issues depending on which nutrients are deficient. For example, Nitrogen deficient plants will not grow as big, and will have yellowing leaves, even on new growth.

Under-estimating Size

Some varieties of cannabis, when given enough sun and nutrients, can easily get 10-15 feet high, even here in the northeast. If your plants are that tall, they can get as wide as 8 feet in diameter. 

Too little space between plants is a common error and stunts growth 

First time growers really don’t believe the plants will get that big, or more commonly, maybe they don’t have enough space in the garden for a plant to take up that much room. 

When plants are spaced too close together they will compete for sunlight and nutrients resulting in smaller plants overall. The areas of overlap will result in smaller flowers. Finally, plants too close together do not allow for proper air movement and can become a haven for mold & mildew.

Lacking Security

Cannabis plants smell. A lot. 

You won’t know how much until it’s too late to move them. Trust me, think skunk smell. All over your land. That innocent little seedling doesn’t smell much and people think “oh she’ll be fine here in my backyard in a downtown residential area.” 

Flash forward three and half months and the whole neighborhood now knows who’s growing in the backyard. Even if you are legally growing there is still the very real issue of plant theft during flowering. I’ve known many people who’ve hidden their plants well on their land only to have all the hard work disappear overnight.

2. Ignoring Your Plants

This general mistake, of not checking your plants daily is the starting point for most of the categories that follow.

Checking in on your plants and how they’re doing will allow you to catch problems before they get too big and perhaps gone too far for you to remedy the situation.

Do you know how to help Droopy?

3. Under or Over Watering

Just like Goldilocks, not too much, not too little, but juuuussst right. 

The common mistake for new growers is to over water in the beginning and under water in later stages of growth. Early on in the 2020 Grow course, I had the students take an oath to not water their plants for one week. Almost all of them were overwatering their teeny tiny seedlings and the baby plants were suffering. 

Later in the season, especially if plants are in pots, newer growers tend to underwater. It’s unbelievable HOW MUCH water the plant can consume in a day. Depending on the size of your pot, you may need to water every day later in the season.

An informed grower can look at a plant and determine from the kind of droop whether the plant has been over or underwatered. (yes, they droop under both conditions) 

4. Not Protecting Your Plants

The three main areas of protection to consider are: predation by insects and herbivores, infection by bacteria & fungi, and finally, from the weight of her own flowers that will snap the branches (not a bad problem to be prevented).

Let’s go into each of these briefly.

Predation By Herbivores

If herbivores don’t have other food sources, they will absolutely browse your cannabis plants even though they are quite bitter. Younger plants are more at risk since they are tender and have less foliage for rabbits & deer to choose from. 

Predation By Insects 

Protection from insects is a much bigger topic. There are a host of insects that when unchecked, will damage your plant, decrease yield and possibly ruin flowers. Daily examination of your plants and knowing signs the insects leave behind are good prevention before bigger problems take hold.

Bacterial or Fungal Infection

The rookie mistake I’ve made, and beginner growers make too often is to pretend the bacterial or fungal infection will just go away. Not true. Infection indicates the plant’s immune system is not working optimally and chances are the infection will continue. Each day when checking for insect predation signs, you can add checking for signs of bacterial or fungal infection. 

Knowing the common infecting agents and what they look like allows you to treat them effectively and save your harvest. New growers tend to scramble for solutions when things like this go wrong and without support they end up taking bad advice and damaging or failing to solve the problem. This is a tough moment, when all the hard work of a growing season is gone with a rapidly spreading fungus. 

5. Not Pruning

I remember the first time a friend pruned my plants. I was horrified. What exactly could be beneficial about CUTTING AWAY MY PLANTS?! 

I’m sharing this with you so you know, I know – how hard to believe and how hard on your heart this next step might be. 

The choice to not prune in places that have lots of rain and/or high humidity risks mold and mildew in the flowers. Not pruning results in smaller flowers overall and that may or not be a “mistake” for some people. If you do want larger flowers and to prevent mold & mildew, pruning and shaping the plant is crucial and should be done at a few stages. 

6. Not Scheduling Time For The Harvest

Harvesting & preparing cannabis for drying takes A LONG time. 

Longer than you might think. Depending on the size of your plant and the experience of the folks working with you, it could take 3-4 hours per plant to prepare the plant for drying.

Many of the first time growers I worked with in my Grow Program were surprised at the harvest and were scrambling to make time in their schedule to harvest.

7. Harvesting at the Wrong Time

Too Soon

New growers are so excited and ready to get their flowers in that they will jump the gun and harvest much too early before the flower has had a chance to fully mature. 

Or they just don’t understand how to tell the difference between underripe and ripe flower. 

Harvesting too soon results in a lower yield and depending on the variety, and a very “zippy” feel to the medicine.  

Of course there are many considerations as to why you would harvest early, but if you don’t have security issues, pest infestation, disease or adverse weather, it’s always best to let your plants fully mature.

Too Late 

In an effort to wait for the exact number of days that the seed packet says or even by watching the telltale signs of ripeness, un-informed growers will miss the other signs the plant is showing that the harvest needs to occur. 

Harvesting too late can result in a more sedating feel to the medicine and a loss of precious flowers. If mold is already in the flowers and the harvest is too late, the mold can take hold throughout the entire flower. 

8. Improper Drying 

Uninformed growers don’t realize that drying can make or break all the work up until this point.

Different methods of drying give the grower options at the end of the season. Regardless of the method, the percentage of water in the plant is crucial, especially if growing for smokable flowers. 

9. Improper Curing & Storage

Curing and storage go hand in hand because how you store your flowers determines how well they cure.

Again, curing is crucial for smokable flowers, but not so crucial for medicine making. Curing is as much an art as it is a science, but very much learnable.

I’m going to be teaching an advanced curing and storage workshop as a bonus for this year’s Grow! Seed to Harvest Mentorship because first time growers are always surprised at the amount of medicine they end up with and need to quickly learn how to handle it.

10. Not Allocating Enough Time For Trimming

If you’ve never trimmed cannabis for smokable flowers, just imagine an amount of time and multiply by ten. Or one hundred. 🙂

Trimming takes a long, long time. 

If you’re growing this year, and you do it right, you need to make sure you schedule more than enough time to process your flowers.


There you have it friends, 10 regrettable mistakes to avoid if you want to grow healthy vibrant cannabis medicine. 

If you’d like to learn more, check out my video 8 Principles for growing and my growing resource guide. This is one of the resources from my Grow! Seed to Harvest Mentorship Online Program, but I’ll give it to you today for free! Get it here.

Want to add 12 – 20 plants to your garden this year?

Of course, if you’re serious and would be glad to have an abundant harvest of beautiful medicine, consider the Grow Program. You can learn more here. The program fills up quickly, so if you have any questions let me know!

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Tammi Sweet

I'm a researcher, educator, guest lecturer, and co-founder of Heartstone Center for Earth Essentials in Van Etten, NY.