Fixing Overwatered Weed Plants | Growers Choice Seeds

Overwatering Cannabis Plants: How to Avoid and Fix it

How to Avoid and Fix Overwatered Cannabis Plants

In this article, we’ll be examining what happens if you overwater your marijuana plants, which is a common mistake that novice growers can easily, and understandably make. We will also look at what the signs of an overwatered cannabis plant are, how to remedy this, and more.

Of the reasons that this is an important topic for cultivators to know how to address is because overwatered weed plants can result in root rot, which, if left undiagnosed and untreated could result in the loss of your cannabis crops.

So, get your watering cans, and let’s get going!

Overwatering Cannabis: Causes and Effects

Chances are, we’ve all accidentally overwatered our marijuana plants. While this isn’t the hugest deal if it happens just once in the life cycle of a mature plant, it could spell disaster if this occurs frequently without being addressed.

The reason that excess water is such an issue for an otherwise healthy plant is that oxygen ends up getting displaced in waterlogged soil, which can suffocate them and lead to root rot.

Close-up of a person sitting cross-legged holding a gardening trowel and digging into a small pot that is surrounded by soil and roots
An in-depth exploration of root rot, what it is, and how to resolve it
Source: Teona Swift pexels

What is Root Rot?

If your cannabis plant roots begin to rot, this is a serious issue as root rot can block the plant’s ability to take in both oxygen and the essential nutrients it needs to grow into healthy plants that produce the cannabinoid-rich buds that you’re seeking to reap at the end of its flowering stage.

Basically, root rot, aka “unhealthy root browning,” is a type of fast-spreading fungal infection that will quickly “attack” the roots of a plant, which in this case applies to cannabis plants. It tends to occur when the cannabis roots have been weakened due to not getting enough nutrients, or being exposed to diseases or stress.

Without doing too deep of a dive, root rot spreads via microscopic spores that spread beneath the soil, or whatever growing medium you are using for your weed crops, via water. As the water transfers through the roots it carries these spores with them, and these same spores will germinate and multiply as they move throughout the root system of your cannabis plant(s). Should this go left unchecked the spores could end up rendering your entire marijuana crops as a total loss. Before getting into what some of the common symptoms of overwatering are, know that cannabis seedlings are particularly vulnerable to root rot.

Signs of Cannabis Overwatering

Provided below are some of the most common signs that you have accidentally been overwatering your outdoor or indoor plants.

If you see any of these signs, then there’s a high likelihood that your marijuana plants have been subject to too high of a watering frequency.

  • Drooping and/or curling overly-saturated leaves: Excess water both inhibits a cannabis plant’s ability to intake oxygen and causes a build-up of water molecules in the leaves.
  • Leaves that are yellowing; have brown, yellow, or rust-colored streaks or spots; and/or have burnt edges or ends: When water suffocates the roots, they are forced to shift their energy to attempt to intake oxygen due to being waterlogged. As a result, they aren’t able to focus on nutrient absorption, which can then result in various nutrient deficiencies. If your plants aren’t getting enough iron, potassium, and phosphorous, your plant’s leaves will let you know by turning yellow or white; having rust-colored, yellow, or brown spots; and/or having edges or tips that look burnt.
  • Leaves are falling off without wilting: An overwatered marijuana plant will start to drop its leaves before wilting due to the same excess water molecules that cause them to droop.
  • Stunted plant growth: This occurs because nutrient intake has been restricted and photosynthesis is occurring at a significantly reduced rate. When this occurs during the vegetative stages, new branches will be both fragile and stunted in size. When overwatering takes place during the flowering period, far fewer new bud sites will be able to develop.
  • Wet soil: Probably the fastest and easiest way to tell if your plants are struggling due to excessive water will be by simply checking the soil. For example, if you are growing a potted cannabis plant in soil, the texture of this particular growing medium will be mushy, which would be a sign that the soil in the pot is “clogged” from the very top to the very bottom. Another quick way to check is to use an inexpensive soil moisture meter that you can get from almost any gardening center.

Overwatered Cannabis Recovery

So, let’s say you overwater your cannabis plants. If you catch it within the first five days or less of having overwatered your crops, you should be able to save your marijuana plants.

However, if you fail to do so in this time frame and continue to overwater, then, unfortunately, there is little chance of your weed plants surviving as the root rot is likely to be far too extensive by that point. And, even if you manage to save your plants, you’re pretty much guaranteed much smaller yields of nuggets that could not achieve their full potential due to experiencing both a severely restricted period of nutrient intake and stunted growth.

All of that said, let’s approach this with a positive mindset and assume that you were able to catch the signs of overwatering in the first five days or less of doing so and provide you with various tips and tricks for how to remedy this and how to prevent this from happening in the future.

How to Resolve Overwatering

Provided below are some steps you can take to, hopefully, reverse the effects of having overwatered your cannabis plants. While there’s no guarantee these steps will work, there is a good chance that when properly executed you will still be able to salvage your crops and not lose out on reaping those THC- and/or CBD-rich buds you’ve been working towards.

The Waiting Period

If your cannabis plants are well into their flowering stage, you will not want to transplant them as this will be too hard on them. In this case, the very best thing you can do is to wait and let the soil dry out for at least two to three days, and if possible, try and place your plant(s) under direct sunlight for a few hours every day to aid in the evaporation process. Once the soil is dry, you can start to slowly give them a bit of water until your plants start to look normal again. For potted cannabis plants, make sure the pot size is appropriate to the plant size and that water can easily drain out the bottom of the pot.

If your plants are in their seedling stage or vegetative stage, you can carefully transplant them to dry soil. Doing so will not only provide the roots with the oxygen they so desperately need, but it should also promote root growth that will replace the ones that were damaged.

Add Enzymes and Nutrients

Adding additional nutrients, such as vegging or budding nutrient mixture, should help to restore and recharge your soil mixture once it is dry. Don’t worry if it takes a week or two for you to notice any significant signs of improvement in your weed plants. Experienced growers also recommend adding what is known as a microbial mix to your soil as this will help to increase microbe growth in the soil, as well as help to encourage nutrient intake so that your plants can grow to be strong and healthy.

In addition, using a soil improver like Plagron’s Pure Zym, which contains natural enzymes, may help to promote the rapid breakdown of dead plant material.

The reason you want to add enzymes is that when they digest the dead roots, a “path” is cleared for your cannabis plants to be able to absorb more nutrients to be absorbed.

Close-up of the rich soil with earthworms in the cupped hands of a person
A deep dive into the various growing mediums for cannabis
Source: Sippakorn Yamkasikorn pexels

Selecting the Right Substrate

While nutrient-rich soil mixture is a fabulous growing medium for most cannabis strains, some growers, especially inexperienced ones, may be more likely to end up overwatering it. As such, when using soil, some veteran cannabis growers say that you shouldn’t follow a strict watering schedule and should instead just water when your plants need it, others say you should water them every two to three days. Our advice is that no matter which option you go with, you always check the moisture level of your soil before watering using either a soil moisture meter or your fingers to check that the first inch of soil or growing medium is dry.

If you’re really concerned about cannabis overwatering, then adding a substrate like perlite to your soil can help as its porous structure allows for any excess water to quickly pass through the soil. This prevents waterlogged soil, and it helps to ensure root health by providing them with the necessary space to grow and to improve their nutrient uptake.

Another good option to help promote good water and nutrient absorption are natural peat combinations.

Avoiding Overwatering Marijuana Plants

In the subsections below, we will look at various tips and tricks for helping you prevent inadvertently ending up with overwatered plants.

Efficient Watering Techniques

Now that you already know why you need to avoid cannabis overwatering, let’s look at some good watering practices.

1. Water your plants in the morning and water at the base of the plant in the soil and not on top of the plant. Doing these two things reduces rapid evaporation and prevents the leaves and stalks from either getting too waterlogged or burned by the heat of the day. These tips are especially important if you are growing your crops outside in a place where summer temps get high.

2. As already mentioned above, always check the moisture retention of your soil before watering. The best way to do so is to either employ the use of a soil moisture meter or your fingers to check that the first top inch layer of soil or growing medium is dry.

3. Water your plants slowly and evenly so that they can really seep in and get all the way down to the roots.

Other Things to Consider

Marijuana plants do need more water than say wheat or corn, and during the main summer growing season from June to October one cannabis plant will consume up to six gallons of water per day when growing outdoors, whereas indoors it will require about 2.5+ gallons of water per day. However, it is important that you only consider these quantities as a sort of guiding rule of thumb, as things like temperature and humidity levels, growing medium, indoor vs. outdoor growing, etc. all impact how much water your cannabis plant will actually need.

In addition, when buying cannabis seeds from Growers Choice Seeds it’s important that you read the product descriptions and consider what kind of environment you will be able to provide them. For example, strains like Cereal Milk and Feminized Dutch that require ample sunshine, warmth, and low humidity levels may be more susceptible to overwatering if they’re being grown in a particularly humid outdoor environment or indoor grow tent that is not properly ventilated with good air circulation. Conversely, strains like Diablo OG, Permafrost, and Pineapple Jack, which are known for producing hardier plants that have a high resistance to mold, mildew, and common diseases, may handle overwatering better than others, but this is not to say that you don’t need to stay mindful and practice good water habits with even the most resilient of strains.

Green cannabis plants growing outdoors in a field
Everything you need to know about cannabis nutrients
Source: NickyPe pixabay


Applying the methods provided above can help you prevent overwatering your cannabis plants to prevent root damage and ruining the yield potential of your crops.

However, if you do accidentally overwater your marijuana plants and catch it in time, there is a good chance you can remedy things by letting your grow medium dry out and adding enzymes and nutrients to your soil.


Q: What are the symptoms of overwatering cannabis plants?

A: The following symptoms are all indicators of having overwatered cannabis plants:

  • Drooping and/or curling overly-saturated leaves
  • Leaves that are yellowing; have brown, yellow, or rust-colored streaks or spots; and/or have burnt edges or ends
  • Leaves are falling off without wilting
  • Stunted plant growth
  • Wet soil

Q: How often should I water my cannabis plants?

A: Many growers say you should water your marijuana plants every 2-3 days, but others do claim that you shouldn’t follow a particular watering schedule and should instead just water when your plants need it.

Q: What should I do if my cannabis plants are overwatered?

If you overwater your cannabis crops and catch it within the first five days or less, you should be able to save them. You will first want to let the growing medium they are in completely dry out, and then add extra nutrients, such as vegging or budding nutrient mixture, as well as soil-improving enzymes like Pure Zym.

If your plants are in their seedling or vegetative stage, you should be able to transplant them to dry soil–just make sure you do so carefully.

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