Don’t Overwater your Cannabis! Here’s How.
Does your grow have wet feet? You may be overwatering your cannabis.
Photo by Esteban Lopez
Obviously, your grow needs adequate water, and the medicinal herb is a notoriously thirsty species. But you can have too much of a good thing.
What does overwatering cannabis do?
Water is essentially the blood, breath, and bones of your cannabis. So how can there be too much of it? To gain a deeper understanding, let’s take a closer look at what the right amount of watering actually does for the grow.
In proper proportion, water keeps stems strong, leaves breathing, and nutrients flowing properly through your grow.
Xylem tissue pulls water and essential minerals up from the roots, and distributes it to the rest of the plant.
Stomata (small holes) on the leaves release pure water vapor to both cool the plant, and encourage more water uptake from the roots.
Properly hydrated cell walls hold the plant up and expand leaves to their fullest. That means the stomata can do their thing, and the chlorophyll can do its thing, making food for the plant and medicine for the planter. 
Watering cannabis in excess leads to:
Cell walls bursting
Plants rely on the vascularity of their cells to stay upright and healthy, but these cell walls aren’t the same as our bones. As they take in more and more water, they strain against one another, and then burst like popped balloons–leading to stress and necrosis.
Plant suffocation
Remember the stomata? Cannabis ‘breathes’, or rather, transpires by taking in mineralized water at the roots and exuding pure water vapor and carbon dioxide from the leaves. When there’s too much water coming in, the “exhale” portion of transpiration cannot keep up with the influx, and the plant will, after a fashion, drown.
Fungal/Bacterial/Viral growth
Why isn’t it safe to play in stagnant water? It’s not just the alligators…
Photo by Tuan Lifecolor
Harmful microbes and fungi like the kinds responsible for powdery mildew, root rot, and other nasties thrive in still, very moist environments, and will kill your cannabis if left unchecked.
Proliferation of fungi also means proliferation of fungus gnats–nasty, fast-breeding little flies that spread fungi from pot to pot, and multiply faster than they can be swatted down.
What are signs of overwatering in cannabis?
How can you tell if your grow is in danger of drowning? Check for these signs:
Wilting leaves
Even though you’ll see freakshow cannabis strains like this:
from time to time, pot leaves are pretty iconic for good reason. If you see the edges of those leaves losing their classic serration, and folding downwards and inwards towards the main leaf ‘veins’, you could be looking at massive cell wall failure due to overwatering.
Discolored leaves
Generally, you want your cannabis to look like a sea of green. While there are black, purple, and even totally white leafed strains–yellowed, browned, and blackened leaves will stand out with other telltale signs of hyperhydration. Any discoloration is cause for alarm, so check grower forums for other pictures of your strain of choice to see whether your weed is struggling.
Slower growing
Even though patience is a virtue for any homegrower, weed grows like, well…a weed. Hemp and cannabis are some of the fastest growing plants on the planet, and can grow up to two inches per day during their vegetation stage. If your plants are not focusing on flowering, and you’re not marking up your height chart on a weekly basis? Something could be wrong.
How do I know overwatering my cannabis is the real problem?
Yellow, stunted, shriveled leaves are the same exact signs you’d expect to see from underwatering your cannabis, or experiencing the dreaded nutrient burn. How are you supposed to tell the difference so you can do the right thing by your homegrow? There are a few more context clues to check.
How hard is it to lift your pot’s pot?
If you’re seeing shriveling coupled with an extremely heavy plant container, that extra weight is probably excess water! Lift with your legs and check the bottom of the pot for dampness if you can do so safely, and you’ll be better equipped to deal with the problem.
Can you “pinch an inch”?
You can also check from the top down to see if your cannabis is hyperhydrated. With freshly washed hands, poke the soil up to your second knuckle. If you can feel definite dampness or wetness, your plant needs you to back away from the watering can.
Does the brown surround?
Discoloration is a common symptom of something wrong–and usually growers tend to think of underwatering before overwatering as the cause. However, both issues will present differently on your cannabis leaves. Underwatering will leave the tips of leaves discolored. Overwatering will manifest as discoloration around the perimeter of the entire leaf. Here’s a fun mnemonic: If the brown surrounds, your weed is drowned.
Soggy or crunchy?
Who knew the the biggest debate in cereal connoisseurship could come to cannabis? If you’re looking at sad, shriveled leaves, give one of them a little pinch and rub between your fingers. Do you have wetness and staining as the result? That’s overwatering! Dry, jagged crunching and flaking? That means your dank is too dry.
What does properly watered cannabis look like?
Cannabis that’s getting the right amount of water will be upright (with or without the help of a trellis for heavy yields), will keep an appropriate color for its strain type, and be flexible enough in all above-ground parts to bend when gently pushed, yet stiff enough to snap back into place with no effort.
What about hydroponically grown cannabis?
If too much water is so bad, why is it that hydroponics is a viable option for growing cannabis indoors? Simply put, it’s the bubbles!
Underwater aeration keeps roots oxygenated, and lets the water move enough that refills and proper filtration are all that’s needed to keep things fresh!
Need more weed knowledge?
Check out One Minute Wednesdays, and feel free to send in any questions you’d like to see and read us answer!
