Additionally, roots pull in oxygen as soil dries and when soil is too wet, the plant can’t pull in oxygen efficiently and essentially can’t breathe.
Keep in mind that as plants get bigger, they will need more water and need to be watered more frequently.
If growing in amended organic soil, it is not recommended to flush plants. This is because the soil already holds all the nutrients the plant needs to thrive, and by flooding the soil you can wash away and damage the complex ecosystem that you’ve worked hard to develop.
How to tell if a cannabis plant needs watering.
Conversely, if a container is too small, the roots won’t be able to stretch out, which can stunt the growth of a plant. Less soil also meant you’ll need to water the plant all the time, which will add labor.
The amount of water your marijuana plants need depends on a few factors:
If a weed plant is very dry, water will run straight through the soil and pot and quickly come out the drainage holes. If this happens, water the plant a little bit and then come back to it after 15-20 minutes and water it again, and maybe even a third time. This allows the soil to slowly absorb water until all of it is thoroughly wet.
Leaves of an overwatered plant look slightly similar in that they droop, except the leaves will be dark green and the leaf tips will be curled.
There isn’t an exact science for watering a weed plant. You can’t observe the roots in most cases to see if they need water. Also, a plant is constantly growing and the climate it’s in will fluctuate, so the amount of water it needs constantly changes.
Here are some tried-and-true tips to keep your weed plants healthy and properly hydrated.
Is your container the right size?
When growing weed outdoors, you’ll need to water more often as the weather gets hotter and less often as it cools.
The best ways to tell if a weed plant needs water is to:
Flushing is an important part of the marijuana growing process, when you stop giving a marijuana plant nutrients and give it straight water. This is done to flush out nutrients that may have built up in a plant during its life.
An under-watered marijuana plant looks droopy and weak, with yellow or brown leaves; there is no strength in the leaves and they look lifeless.
Flushing marijuana plants before harvest.
Below are general estimates and are meant to give growers a rough sense of frequency of waterings; if a plant needs water and it falls outside of these ranges, water it.
Plants are ready to transplant when a healthy root structure encompasses most of the soil and the roots aren’t bound. When transplanting, take time to look at the quality of the roots: Bright white roots with a strong, thick structure is a sign plants are getting watered correctly.
You want to water a plant enough to soak all the soil in the pot. Water should pool up on the surface of the soil when you’re watering, and come out the drainage holes in the bottom of the pot after a couple seconds. If water sits on the surface of the soil, that means it’s too wet and doesn’t need more water.
A flush can also be done to clear plants of nutrients if they have a nutrient imbalance, such as nutrient lockout, when your plants are overloaded with nutrients and unable to absorb new ones.
Like all plants, cannabis requires water in order to perform its basic functions. Water helps plants absorb nutrients from the soil and then moves up the plant and into the leaves, and without it, the plant can’t survive. But giving a marijuana plant the proper amount of water may be more difficult than you think.
If you’re growing marijuana in soil or another growing medium like coco coir, you will have to hand-water your plants. Watering is an important part of growing cannabis indoors, and knowing how to water your plants will save you a lot of frustration!
Making sure you keep adding water until you get run-off is also a great way to make sure that your plants are draining properly.
How to improve the drainage of your growing medium.
How often do you give your cannabis water?
Therefore, when growing in amended soil you should only water until you get just a drop or two of water runoff out the bottom. You want to ensure you gave enough water to reach the bottom of the pot without letting a significant amount of water run out the bottom.
My grow tent is 2 feet deep and this reaches the plants in the back. However, I don’t think the tube is long enough to reach the back if your space is deeper than that.
That being said, you can plant your seeds right into their final container. Just be careful not to overwater your seedlings at first if they’re in a big container as they’re not drinking much water in the beginning.
In coco coir, you want to water every 1-2 days if possible and adjust the amount of water you give accordingly. The top inch doesn’t need to completely dry out between waterings.
If plants are drying out in 1 day or less, try giving more water at a time or transplanting to a bigger pot.
Underwatered Marijuana Plants.
How to Collect Runoff Water.
If Growing in Composted or Amended Soil, Give Just Enough Water That the Soil is Wet All the Way Through.
Some growers set up elaborate drip feeds to pump water if they have a lot of plants they can’t easily reach, both homemade or pre-made.
A downside to the Bucket Head is it’s a little loud, just like most wet vacs. Luckily you only need to use it for a few minutes after watering your plants!
Watering Too Often? Barely at All?
Growing in Super Soil?
Overwatered Marijuana Plants.
Go back to step 1. Note: If water takes a long time to come out the bottom, or if pots take longer than 5 days to dry out before the next watering, you may actually have a problem with drainage (more info below) or need to give less water at a time. If your plants are very small compared to the container they’re in, give water more sparingly until plants get bigger.
Sometimes soil and soilless growing mediums like coco coir start to collect natural salts from fertilizers that never get washed out.
How to water cannabis properly (when using a well-draining potting mixture with liquid nutrients)…
These 1’x2′ plastic plant trays work well if they fit your space. You can fit four of them in a 2’x4′ grow tent (this is the grow tent I use) with up to two plants each as long as your plant containers are 11″ wide or smaller at the base.
If you notice any of these issues with your plant, it could be the result of too many or too few nutrients. You’ll need to adjust your growing strategy to support your plant’s health.
But what does that TLC look like? What steps do you need to take to support your cannabis seedlings through the seedling stage and as they grow into mature marijuana plants?
But growing your seedlings outdoors can be tricky. Because you can’t control sunlight, there’s no way to ensure your cannabis seedlings are getting the light they need to grow properly. A cloudy day can prevent your seedlings from getting enough light and throw off your entire growth process.
Nutrient deficiencies can come from a variety of places. “Hot” potting mixes that contain too many nutrients could cause nutrient toxicity. On the other end of the spectrum, under-watering can cause a deficiency in the key nutrients your plant needs to grow.
A nutrient deficiency can cause serious issues for your growing plant, so part of proper care is knowing how to spot the signs of a nutrient deficiency.
Choose the right lighting.
When it comes to watering your seedlings, you want to give them the water they need to thrive. But too much water can actually have a negative impact on the growth process, so it’s important to be mindful of how much you water your seedlings.
But what does that care look like? What are the key things to know when it comes to how to take care of marijuana seedlings?
If you’re not sure how much water is too much water, keep in mind that you want the growing medium (AKA the soil) to be damp and moist — not soaked and oversaturated.
Environmental conditions are essential to growing healthy cannabis seedlings, and some of the most important conditions to control are temperature and humidity.
The root system of a seedling isn’t elaborate; the roots are small and don’t need much water to grow. Misting the plants with water once or twice a day should be plenty to give them the hydration they need to grow.
If you’re growing your seedlings outdoors, they’ll need to be exposed to as much sunlight as possible. Photo by: Gina Coleman/Weedmaps.
This stage — moving from germinated cannabis seeds to cannabis plants with the maximum number of ridged edges per leaf — is the seedling stage.
If you try to grow your seedling in a container that’s too large, the root system won’t be able to absorb all the water in the soil. If you start growing your seedling in a container that’s too small, the roots won’t have space to extend and will start to wrap around themselves, which will also impact their ability to absorb water.
Choosing the right pot is an essential part of caring for your growing plant. Photo by: Gina Coleman/Weedmaps.
Your cannabis seedling needs space to grow. But too much space and too little space can both create problems for your plant.
What happens during the seedling stage?
Like any plant, seedlings need light in order to grow and thrive. But not all light is created equal. If you want your seedling to grow into a healthy cannabis plant, you need to expose it to the right type of light.
As the plant grows, it starts to produce more fan leaves — and those leaves continue to develop the ridged edges that you’ll immediately recognize as the marijuana plant. As more leaves grow, more ridged edges develop until finally, the plant is fully grown with each leaf reaching its maximum number of edges (which can be anywhere from 5 ridges per leaf to upwards of 10).
In the seedling stage the cannabis seedling is in need of a lot of TLC to grow into a healthy cannabis plant. Photo by: Gina Coleman/Weedmaps.
When you’re growing cannabis, you want to keep your plants strong and healthy through every stage of the growing process — and that includes the seedling stage.
Some red flags that signal your seedling may have a deficiency in nutrients (or nutrient toxicity) include:
Before we jump into how to care for your cannabis seedling, let’s quickly cover what happens during this grow stage.
You should also aim to keep humidity in the grow environment at a higher level, typically around 70 percent. That way, the plants can absorb moisture from the environment to develop stronger roots without getting weighed down by over-watering.
The seedling stage is an incredibly important part of the growing process; because the cannabis plant is still young and fragile, proper care is essential if you want to lay the foundation for a healthy mature plant.
If you’re growing your seedlings outdoors, they’ll need to be exposed to as much sunlight as possible. Keep them in the sun from sunrise to sunset; the more sunlight exposure they get, the better.
Choosing the right pot is an essential part of caring for your growing plant. You need a pot that’s going to give the root system space to grow, but not so much space that the roots won’t be able to absorb all the water in the soil. You should also make sure the pot has drainage holes to get rid of any excess water that could overwhelm the plant.
Growing your seedlings indoors with artificial light gives you more control over the process, making it easier to ensure your plants are getting enough light each day. If you’re growing with artificial lights (compact fluorescent lights that emit cooler, blue spectrum light are especially effective), aim to give your plants 18 hours on and six hours off each day.
The seedling stage can be an especially vulnerable time in the growing process. The cannabis seedling is in need of a lot of TLC to grow into a healthy cannabis plant.
The growing process has four key stages: the seed germination stage, the seedling stage, the vegetative stage, and the flowering stage. Once the cannabis seeds germinate and are placed into their growing medium (like a potting mix), they start to root into the soil as the stem grows upward, sprouting two cotyledon leaves, which help the plant absorb light and continue to grow.
The temperature in your grow environment shouldn’t exceed 80 degrees Fahrenheit, otherwise the seedlings may grow too tall. (You should also plan on lowering the temperature at night to about 70 degrees Fahrenheit.)
Let’s take a deep dive into how to care for your baby marijuana plant so you know exactly how to take care of your growing seedling and make sure it grows into a healthy, mature cannabis plant.