Can you Overwater Cannabis? Know the Signs and the Solutions - Happy Hydro

One of the most frequent issues novice growers face, especially when growing in soil, is overwatering. Cannabis, in particular, can be finicky.

Although you are working overtime to keep your plant happy, it's easy to go overboard. Too much water can be just as dangerous as too little. Overwatering cannabis will eventually drown it. Learning how to set up a perfectly moist (but not too moist) environment in advance, with proper soil, drainage, humidity, and equipment is essential. It's also helpful to know the signs of overwatering, in case it ever happens to you. 

The following is a quick and dirty guide to overwatering cannabis. Learn to recognize the signs of overwatering, understand how much water your cannabis actually needs, and grab some helpful tools to reduce the risks.

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What Are the Signs of Overwatering Cannabis?

A happy, well-watered cannabis plant stands up straight, with perky leaves radiating upwards and outwards from the stalk. The leaves should feel dry and slightly papery to the touch, even after watering.

Quality, well-drained soil retains moisture but doesn't become muddy or clay-like. Water shouldn't pool on the surface, nor collect at the bottom of the pot. The container should allow for natural drainage, but stay slightly moist following a good watering.

If you have overwatered your plants, you'll see the first signs appear after a few hours. The entire plant appears to droop downwards. It will look sad and heavy as the leaves will turn downwards, gently curling under. This is the primary indicator of a problem with overwatering, and will typically appear several hours after the last water.

Over time, if the problem persists, the plant will begin to yellow. It may also display signs of other problems. Overwatering can lead to nutrient deficiencies; the plant struggles to absorb any through its drowning root system. Eventually, if left unchecked, it will die. All plants, including cannabis, actually use their roots for breathing oxygen. Fluffy, well-draining soil facilitates this process. But, if the plant is literally swimming in water, it's unable to access the oxygen it needs. You can kill your cannabis through drowning.

How to Water Cannabis Properly 

With a simple adjustment to your watering schedule, it is relatively easy to save a plant suffering from overwatering. But, you may want to consider the entire set up, is it actually responsible for some of the issues? Both the container and the soil can play a big part in how well (or otherwise) the environmental conditions facilitate drainage.

Cannabis needs soil with high drainage. Vermiculite and coco noir are great examples of soil additives, which can help with drainage. Drainage holes in the container are also critical to ensure the water doesn't pool around the roots. Most soil-based growers recommend a two to three-day watering schedule. Between each watering, check the surface of the soil. It should feel dry but remain damp one or two inches below the surface. Use your finger as a moisture test, or invest in a digital moisture meter to take the guesswork of it.

Generally speaking, when you do water, aim for 15 to 20 percent of the water to runoff through the drainage holes. This is a good sign that the water has reached the bottom of the container, for full saturation.

How much water should you give your cannabis plants? There is really no one-size-fits-all number. It depends on the size of your container, the environment you are growing in, and the strain. The best way to settle on a watering schedule is through careful daily checkups. Using a digital moisture monitor (or the simple finger check), water when the surface has dried out, but the inside still feels slightly damp. Monitor the situation until a pattern emerges.

How to Reduce the Risk of Overwatering

Again, set yourself up for success from the get-go. Build good soil, use the right containers, and automate the watering process to remove the risk of human error.

Here are a few suggestions to get you started:

  • Use High Drainage Soils

    Avoid soils with high clay content easily compact, turn muddy, and don't drain well. Use soil with a good structure, that has loose, lofty, texture but with some moisture retention. Several brands remain favorites among growers, including Fox Farm Happy Frog Potting Soil

  • Blumat Automatic Irrigation

    This is a fully-automatic, self-watering system for happier healthy plants - with no risk of overwatering. Blumat works on a genius, yet straightforward mechanism. Hoses connected to ceramic "carrots" monitor the moisture in every container. The system automatically waters if and when needed, making growing cannabis that much easier.

  • Digital Moisture Meter

    Never wonder about the moisture content of your soil again with a moisture monitor. Working in conjunction with the Blumat Automatic Irrigation System, a digital monitor helps reduce mistakes, and takes the onus off you, the grower. If you don't trust the finger test, or just want confirmation, trust the moisture monitor.

  • Fabric Pots

    Cannabis cultivators often prefer to grow in fabric containers, as opposed to plastic containers. Fabric breathes and improves drainage. Fabric pots are affordable, compact, and adaptable containers for growing cannabis and beyond.

Not to Much, Not too Little, Finding the Balance

Overwatering is just as big a problem as underwatering. Too much water drowns the roots, reducing the ability for the plant to absorb oxygen. If you notice sad, droopy leaves following watering, this is the main indication you are overwatering. 

Start with good soil, fabric containers, and a moisture monitor to reduce the risks of overwatering from the very beginning. Stick to watering on a regular two to three-day schedule, but only water once the soil surface has dried. Overwatering can damage cannabis, but it's usually easy to rectify with simple adjustments.

Author | Chris McDonald

With two decades of expertise, Chris leads Happy Hydro in redefining sustainable gardening and delights in backpacking adventures, mind-expanding journeys, and creating memories with his loved ones.

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