The burnt leaves on this cannabis suggests stress caused by incorrect lighting.At one time or another, most cannabis growers make mistakes in their grow op that cost them both time and money. So, let’s unpack these too-common errors and see how best to avoid them.
1. Sudden Big Changes To Your Growing Methods & Materials
I used to grow in a rockwool drip irrigation system and knew very well how to get successful crop cycles. After several years of using the same rockwool system and hydroponics nutrients, I had my feed program, irrigation timing and watering amounts completely dialed in. It was like I was running my grow op on autopilot.
Then I saw grow rooms using deep water culture (DWC) and I too wanted the huge white roots, fast growth, and supercharged yields typical of this cultivation method. Doing very little research beforehand, I mothballed my rockwool system and installed DWC simply by copying the materials, systems and methods I saw in other DWC grow ops.
But I found out fast that growing in DWC requires more attention and time than my precious rockwool system ever did. My first two crop cycles were disasters; I lost a lot of money. In retrospect, what I should have done is keep my rockwool system running, but with fewer trays, added a small DWC system, and conducted a side-by-side comparison.
The Solution
Changing so many factors of my grow op all at once, every element was affected. Instead, I should have made incremental changes to see how these tweaks worked on a small scale, before making a major change that negatively impacted my entire grow op.
2. Not Enough Light For Your Grow Op
Many growers don’t provide their plants with either enough light, or the right kind of light and light penetration.
The old-school grow-room style has at least one high intensity discharge (HID) grow light hanging stationary above plants. Light spills down from above, but fails to reach deep enough into the plant canopy, and the sides of plants are similarly cast in shadows. Lack of light reduces yields, slowing growth, maturation and resin production.
The Solution
Putting grow lights on light movers is an easy way to disseminate light at angles so that it penetrates lower into the plant canopy and sides of your grow. You can also use LEDs as side lighting to send light to parts of the canopy where top lighting cannot reach.
These tactics are especially useful in bloom phase to increase bud size, resin gland formation, and bud ripening.
3. Cannabis Carbon Dioxide Follies
Adding carbon dioxide to your grow-room ambient air when lights are on can increase growth rate and yield by as much as 10–30 percent. But you must keep your grow room sealed without an exhaust fan running while you’re adding CO2, and you’ll have to spend money on CO2 tanks, regulators, monitors, CO2 burners, and related equipment and supplies.
I’ve seen growers mistakenly venting their rooms while pouring CO2 into them — and the CO2 leaves almost as soon as it enters. It’s a big waste of money and time.
Another mistake growers make is using too high a concentration of CO2. Excessive CO2 harms plants rather than helps them, and is wasted expense.
Growers also err by adding carbon dioxide to their ambient grow room, yet failing to adjust the rest of their crop inputs to balance the increased metabolic rate CO2 creates in marijuana plants.
The Solution
When you add CO2, you must feed your plants more water, nutrients and light. Increased amounts of these crucial inputs support the faster metabolism created by added CO2.
4. Enough Space To Grow
There’s no formula for how many plants you can fit under a grow light, because there are so many types of grow lights, cannabis strains, styles of trimming and training, and grow-room methodologies.
Aside from sea of green growing, however, there is one general rule of plant spacing: Don’t put the plants so close together that their leaves and buds are touching each other.
When plants are so close as to be touching, diseases and pests can spread easily, aeration isn’t as effective, growth is inhibited, and bud size can be negatively impacted.
The Solution
Cramped grow rooms often have bloom-phase plants in which only the top of the canopy sees any light or air movement. The lower two-thirds of the plants are a wasted zone. However, when plants are placed so there’s ample space around each one, they grow better, you can access them better, and you get bigger yields.
5. Don’t Forget To Foliar Spray Your Plants
Foliar spraying is great for your marijuana, but most indoor growers don’t do it properly, if at all. Indeed, foliar spraying can be messy, has to be done when grow lights are off, and takes extra time out of your day.
But foliar spraying offers great benefits. It cleanses the tops and undersides of leaves so that debris, mold spores and fungi are washed off. Your plants simply breathe better with clean leaves.
The Solution
If you’re using inoculants and nutrients in your foliar spray, those nutrients are fed to your plants while protecting them against powdery mildew, gray mold, spider mites, thrips, aphids, mealybugs, budworms, whiteflies and fungus gnats.
My foliar feed formula is no more than 210 ppm twice a week at pH 5.7, with equal amounts of B-52, Rhino Skin, Piranha beneficial fungi, and SNS 209.
Growers who do use foliar spraying commonly make the mistake of doing it while grow lights are on. This harms leaves and dries up the spray before leaves can absorb whatever’s in the spray. Do it one hour before your lights come on.
6. Grow Phase Flaws
Many growers view bloom phase as the fun phase, and grow phase as a chore to get through as soon as possible, with the least amount of attention and inputs. However, this attitude can be a precursor to failure.
Many growers run a grow phase that’s too short. From seed, your cannabis needs at least 4–5 weeks from germination before you start bloom phase, if not longer. From clone, unless you’re doing sea of green, your plants need at least 3–4 weeks.
The Solution
Your young plants simply need that time to build roots, structure, hormones and leaves before they’re ready for bloom phase. If you rush through grow phase too quickly and start bloom phase before your cannabis plants are ready for it, then your plants will struggle in bloom phase and produce far fewer buds, cannabinoids and terpenoids.
7. Cutting Cannabis Corners Cuts Pot Profits
Some growers want to spend as little money as possible on nutrients, grow lights, fans and general grow supplies. Well, you get what you pay for.
One of the biggest el cheapo mistakes is using a non-targeted fertilizer like Scotts Miracle-Gro or Peters fertilizers instead of nutrients made specifically for cannabis. The nutrients found in Scotts and Peters fertilizers are extremely harsh, they burn roots, and they produce gangly, poor-yielding plants overloaded with nitrogen and toxicity. These problems are further compounded when low-expenditure growers use regular tap water instead of reverse osmosis water.
And when it comes to grow lights, some growers have no choice but to use fluorescent or low-power LED for their entire crop cycle, because they can’t manage the heat and electricity draw of professional LED and HID grow lights. But the ultimate price of spending less money on grow lights is a smaller yield.
The Solution
In general, the better you treat your plants, the more you’ll harvest. By giving them the quality equipment, supplies, hydroponics nutrients, water and environmental conditions, the more potent your harvest will be.
8. Harvesting Harms To Your Cannabis Plants
Harvesting either too early or too late are very common grower mistakes, and are easy to make if the grower doesn’t understand how to properly monitor resin glands and plants.
Many growers trust the bloom-phase duration estimates given by cannabis seed breeders and sellers, but those estimates are generic and can be unreliable.
If you harvest too early, you lose cannabinoids, terpenoids and harvest weight. Harvest too late and the cannabinoids and terpenoids are degraded by being overripe. And even if buds weight slightly more, the high, taste, and scent are likely to be compromised.
The Solution
Perfect your harvest regulation by using magnification devices such as a magnifying loupe to examine resin glands and time your harvest based on glands’ appearance, clarity and structural integrity.
9. Cannabis Sampling Errors
Growers want to know how potent and tasty their buds are, especially when the season is over, and dried and cured buds are ready to sample. Problem is, growers often get stoned all day every day, so they’re in no condition to accurately grade their cannabis.
I’ve heard of one commercial cannabis investor who owns a chain of Colorado retail marijuana outlets. The investor and his business partners, all of whom are chronic stoners, had to grade 23 strains of weed in order to rank and price them accordingly. They started the grading session stoned and at the end they were barely conscious.
The different strains were put in the shops and budtenders were schooled in what to say about the potency and effects of each strain. However, because the assayers hadn’t been anywhere close to sober enough to even marginally measure the quality and potency of the strains, their descriptions were way off.
Customers came back to the stores in droves, demanding refunds and complaining that the strains weren’t as described. The stores’ reputation suffered considerably.
The Solution
Several days before it’s time to sample and grade your wares, try to have a tolerance break so you can get an accurate read on each strain’s taste and outcome.
We all make mistakes growing, processing, and working with marijuana. Now you know about the mistakes ahead of time, and your cannabusiness will be better because you’re less likely to fall victim to them.
