How Much Water Does a Weed Plant Take?

The journey to cultivating thriving cannabis plants hinges significantly on mastering the art of plant watering. It’s a balancing act where too little or too much water can veer your plants off the path to robust growth. Despite the information available, misconceptions about proper watering techniques persist, leading many cultivators astray.

This guide aims to dispel these myths, equipping you with the knowledge to recognize your plant’s needs and adjust your weed watering practices accordingly.

Weed Over-Watering

How Much Water Does a Weed Plant Take?

While there’s no one-size-fits-all answer to how much water I give my plant, here are general guidelines:

  • Seedlings: Approximately 250 ml (about 1 cup) of water every other day.
  • Vegetative Stage: Gradually increase to 1-2 liters (about 1/2 to 1 gallon) per plant every other day, depending on the size and growth rate.
  • Flowering Stage: Needs may slightly decrease, but closely monitor plant response to water adjustments.

It’s essential to monitor the soil’s moisture level—watering when the top inch (2.5 cm) of soil feels dry to the touch is a good rule of thumb.

Monitoring and Adjusting

Observing plant behavior is key. Signs of overwatering include drooping leaves and a lack of growth. Underwatering signs include dry, curled leaves. Adjustments should be made gradually, and plants should be monitored for response.

Recognizing the Thirsty Cannabis Plant

Understanding the signs of a thirsty cannabis plant is crucial. Underwatered plants often display drooping and weak appearances. In contrast, overwatered plants exhibit leaves that curl down into a “claw” shape. The key to differentiating between the two lies in observing the soil and plant color.

A simple finger test or pot weighing can reveal much about your plant’s hydration status, steering you away from the pitfalls of over- or under-watering.

Perfecting Watering Technique

Watering your cannabis plants isn’t just about frequency; it’s about technique. Water is used less often but more thoroughly to ensure it reaches deep into the roots, promoting healthy growth without causing pooling or fungal issues. Aiming for the middle of the substrate before moving to the edges ensures an even distribution that encourages roots to explore the pot fully​​.

Environmental Impact on Watering Schedules

Environmental factors such as temperature and humidity are pivotal in determining your plant’s watering needs. Plants may require more frequent watering in higher or lower humidity, whereas cooler temperatures and higher humidity might reduce the need. Adjusting your watering schedule in response to these conditions is essential for maintaining optimal plant health.

Weed Watering

Ensuring Water Quality

The quality of water used in irrigation significantly impacts plant health. Critical steps include using purified or reverse osmosis (RO) water, adjusting pH levels to the ideal range (6-7, ideally 6.5 for soil), and ensuring the water is free from harmful contaminants.

Hard water, rich in minerals, can lead to nutrient imbalances, while soft water allows for more precise control over nutrient levels.


Proper watering is both an art and a science, requiring attention, understanding, and adjustment to the unique needs of your cannabis plants. Remember, the goal is not just to grow cannabis but to cultivate plants that thrive, producing the highest quality buds.


Can the type of water use affect marijuana plant growth?

Yes. The type of water used can significantly affect cannabis plant growth. Rainwater is often considered the best for cannabis due to its natural pH balance and absence of chlorine or other chemicals found in tap water.

If using tap water, it’s advisable to let it sit for 24-48 hours to allow the chlorine to evaporate, or consider using a filter to remove contaminants.

How does the choice of container size impact watering?

Container size affects water retention and drainage. Larger pots will retain moisture longer, requiring less frequent watering, but risk root rot if overwatered.

Smaller pots dry out faster and might need more frequent watering. The key is to match the pot size with the plant’s size and growth stage for optimal moisture balance.

Is it beneficial to adjust watering schedules based on the strain of weed?

Yes. Different cannabis strains may have varying water needs based on their genetic makeup. Some strains, especially those originating from arid regions, might be more drought-tolerant, whereas others from tropical areas may require more frequent watering.

Researching your strain’s needs or experimenting with watering frequencies can help optimize growth.

How do foliar sprays relate to watering practices?

Foliar spraying can complement your watering routine by providing nutrients directly to the leaves, helping with nutrient absorption and mitigating some soil-based issues.

However, it should not replace proper soil watering practices. Foliar sprays are best used early morning or late evening to avoid leaf burn.

Can mulching help with cannabis water retention?

Absolutely. Mulching around your cannabis plants can help retain soil moisture, reduce water evaporation, and keep root temperatures stable.

Organic mulches like straw or wood chips can also add nutrients to the soil as they decompose. To prevent rot, ensure the mulch isn’t touching the plant’s stem.

Are there watering systems that can improve efficiency?

Yes. Systems like sub-irrigation and wicking beds can significantly improve water use efficiency by delivering water directly to the roots from below, reducing evaporation and minimizing the risk of overwatering. These systems are especially beneficial for large growers seeking to conserve water.

How important is monitoring runoff pH and EC in watering weed?

Very important. Monitoring your runoff water’s pH and electrical conductivity (EC) can provide valuable insights into the soil’s health and the plant’s nutrient uptake.

Adjustments to your watering or feeding schedule may be needed if the runoff pH or EC levels are consistently outside the ideal ranges for cannabis.

Alex Ramsey

Alex Ramsey

Cannabis Industry Copywriting Specialist

He combines a deep understanding of cannabis with a passion for crafting engaging content. With a focus on demystifying cannabis through education, Alex contributes to the industry’s growth with content that sells, educates, and engages the community.

Learn more about 420 Ergonomics, our team.

Latest at the Weed Blog

What is Delta-8?

What is Delta-8?

In the ever-evolving world of cannabis products, Delta 8 THC has emerged as a popular and legal alternative to Delta 9 THC, providing users with a milder, less intense experience. This article explores some of the leading Delta 8 brands that have carved a niche in...

read more
What is THC-H?

What is THC-H?

The world of cannabis is dynamic, with continual discoveries and advancements. One of the latest entrants that has sparked interest among researchers and cannabis enthusiasts is Tetrahydrocannabihexol, more commonly referred to as THC-H. The genesis and structure of...

read more
How Long Does Weed Stay Good?

How Long Does Weed Stay Good?

So, let's address the fundamental question from the outset: how long does weed stay good? Properly stored marijuana can keep its potency and flavor for about 6 months to a year. However, the quality of your stash depends on various factors, including storage methods...

read more
What is Myrcene Terpene?

What is Myrcene Terpene?

Myrcene, a name often encountered in discussions about terpenes, represents a fascinating facet of nature’s aromatic compounds. Let's delve into the intricacies of myrcene, exploring its characteristics, sources, benefits, and potential applications, drawing upon a...

read more