When to Water Marijuana Plants: Lights On or Off?

One of the most important parts of growing healthy and potent marijuana plants is watering them correctly. While this might seem like a straightforward task, there are many factors to consider, including the time of day you water your plants. In this article, we'll explore whether it's best to water marijuana plants when the lights are on or off so that you can cultivate the best cannabis possible.

Watering Cannabis Plants: The Basics

Before we dive into the main question, let's first review some of the basic principles of watering cannabis plants. The goal is to keep the soil moist but not waterlogged. Overwatering can lead to root rot, which can be fatal to your plants. On the other hand, allowing the soil to dry out completely can stress the plant and lead to stunted growth or even death.

The best way to know when to water your plants is to stick your finger into the soil up to about the first knuckle. If the soil is dry at that depth, it's time to water. If it's still moist, wait a day or two and check again. Another technique is to lift the pot and gauge its weight. A dry pot will be noticeably lighter than a wet one.

Watering When the Lights Are On

Now, let's get to the main question: is it better to water your marijuana plants when the lights are on or off? The answer is that it depends on your specific situation. However, there are some general guidelines that can help you make that decision.

One advantage of watering when the lights are on is that the plants will be actively photosynthesizing, which means they are taking in water and nutrients and using them to create energy. If you water during this time, the plants will be able to absorb the water and use it more efficiently. Additionally, watering during the day can help prevent the growth of mold or mildew, which can happen when plants remain damp for too long.

However, watering when the lights are on can also cause some problems. For example, if you're using a hydroponic system that relies on circulating water and nutrients, water droplets on the leaves can act like magnifying glasses and burn the plant's tissue. This is known as "leaf burn." Moreover, watering when the lights are on can lead to an increase in humidity, which can make it more difficult to control the environment and prevent the growth of mold or fungus.

Watering When the Lights Are Off

Watering when the lights are off is another option that you might consider. One advantage of this approach is that the temperature in the grow room will be lower, which can reduce the risk of leaf burn. Additionally, if you water when the lights are off, the water will have more time to soak into the soil before the plants resume photosynthesis. This can help prevent the water from evaporating too quickly and make sure the plants absorb as much of it as possible.

However, watering when the lights are off can also have some disadvantages. For example, if the soil is too wet, it can create an oxygen-poor environment that can lead to root rot. Additionally, if there are any pests in the soil or on the plant, watering when the lights are off can create a more favorable environment for them to thrive.

Conclusion

So, when should you water your marijuana plants? The answer depends on your specific situation. If you're growing in a hydroponic system, you might want to water when the lights are off to reduce the risk of leaf burn. If you're growing in soil, watering during the day when the lights are on might be better for preventing mold or mildew. In any case, use your judgment and monitor your plants closely to ensure they're getting the right amount of water at the right time.