Watering marijuana outdoor plants may seem like an easy endeavor, but there is more to it than just adding tap water. While watering is not an exact science, it is important to know how much and how often to water and the best method to use.
How Much Water to Give Outdoor Marijuana Plants
The amount of water that growers should give their outdoor pot seeds will vary depending on a few factors including the stage of growth, soil condition, and growing conditions. Growers will need to adjust the amount of water they give the plants as they go. Fortunately, as long as the plants have excellent drainage, there is a wide margin for error in how much water they can handle.
Size of Plants
The first factor growers must consider when watering is the size of their plant. It may be obvious, but a seedling will not require nearly as much water as a plant that is fifteen feet tall (much more likely if you are growing cannabis sativa seeds). In comparison, autoflower strains like our bruce banner auto will rarely surpass two or three feet in height.
Regardless of strain, the seedlings need their soil to be wet constantly until they grow at least a few inches tall. Then you can space out watering to let the mature plants dry out a little bit in between each drink.
– VEGETATIVE STAGE. Marijuana plants will need between 10 ounces and 2 liters in a single watering.
– FLOWERING STAGE. Plants that have entered the flowering stage may need even more water, so the grower will need to watch the plants closely for signs of dehydration.
Type of Soil
A significant factor in determining the amount of water needed is the type of soil in which the plants are grown. Soil that is highly absorbent and holds water for a long time will need to be watered less often, such as those rich in clay. Sandy soils will have a harder time holding moisture, so plants will need to be watered more frequently.
If plants are grown directly in the ground, growers must be conscious of ground water. Even if the soil does not hold water well, if ground water is close to the surface, the plants’ roots may find wet soil, which will change the amount of water they need.
Weather has a major impact on how much water plants need. When temperatures are hot and dry, water will evaporate from the soil much faster. Growers will need to compensate for this loss with a greater volume of water. If it rains or if the temperature outside is cool, then growers will need to water sparingly to avoid over-watering.
Intensity of the Sun
Many people grow cannabis plants in hot, dry climates with little to no cloud cover or rainfall, such as parts of California. In these areas, growers are constantly battling the intensity of the sun to keep their plants sufficiently moist. As the sun beams down on the top of the soil, it evaporates water before plants can absorb enough to thrive. For this reason, many growers will water their plants continuously over time to ensure the plants get enough.
Over-watering can seriously damage a cannabis plant. Over-watering can cause a plant’s growth to slow down and cause leaves to droop and turn yellow. Additionally, it can lead to root rot and mold growth, which will kill a plant fast.
Still, it is essential for growers to understand that it is more important to space out watering sessions than it is to worry about giving too much water at one time. While plants should not be drenched for hours on end, they can survive if they are allowed to dry out slightly between watering sessions.
When to Water Outdoor Marijuana Plants
Growers often stick to a watering schedule that is anywhere between every two days to once a week. In reality, when to water a plant is determined by several factors, and the schedule will need to be adjusted continuously.
Growers who usually water once a week may need to up their sessions during a heatwave. Additionally, watering sessions often need to be increased when plants are in the middle of their thirsty flowering stage. Once your alien gorilla glue plants start to bud, the roots will drink up extra water to support all that additional cell growth. The best thing a grower can do is to become familiar with the signs that show their plants need to be watered.
Signs a Marijuana Plant Needs Water
The most obvious sign that a cannabis plant needs water is if the leaves start to droop. If this sign is observed, growers should water their plants immediately to avoid further damage. As dehydration progresses, the plant’s leaves will turn yellow or brown and dry out. Plants in full bloom may have some yellow leaves that fall off on their own, but they will never appear lifeless and weak like they would if they were dehydrated.
Instead of waiting for the plant to react to a lack of water, growers can check the soil. They can do this by sticking their fingers one to two inches into the soil to see if it is still moist. If it is not, then they will need to water the plants.
Additionally, growers who have their plants in pots can lift the pot to see how heavy it is. If the pot is light, they will need to water. If the pot is still heavy, they should hold off a while longer.
How to Water Outdoor Marijuana Plants
Many growers have adopted strategies to make watering more efficient and help their plants retain water for longer. These include:
Hand Carry Water
Hand carrying water is an excellent option for those who are growing a few plants near a natural body of water. Growers who need a stealthy watering method may also find this the most prudent way to water their plants.
Use a Water Pump
Cannabis growers with a larger, more permanent set up should consider using a water pump to transfer water from their preferred water source to their plants. This method is an excellent option for anyone who makes compost tea in a separate container before watering their plants, as the pump can carry that fertilized water to the plants. Growers using a water pump will need access to either electricity or gas to power their pump.
Slow-drip irrigation is a simple watering strategy that involves cutting the bottom off of a 2-liter or one-gallon bottle, poking holes in the cap and around the sides of the bottle close to the top, and then burying it about halfway into the soil. Growers will need to fill the bottle with water for the plants periodically. The bottle will slowly deliver water to the roots over an extended period.
Drip Line Irrigation
Drip line irrigation is a great way to water all plants evenly every time the grower waters. Growers simply run a specialized watering line throughout each of their plants and connect it to their preferred water source. These lines may have prefabricated holes, or growers may have to make holes themselves. Small sprinklers can be attached to each hole by a small hose, or the hole itself can be the source of water, depending on what the grower prefers. If sprinklers are used, growers may want to check them for blockage periodically, as small particulates from fertilizers can block water flow.
The simplest method of watering cannabis plants is by using a plain garden hose. Growers who use a hose from their city water source or well should be sure to check the pH, chemical content, and salt content of their water before using it on their plants. If the water is not suitable directly from the tap, growers will need to put it in another container to treat it before using it on their plants. Depending on the container, growers can attach a spigot and use a hose to water their plants from that container.
Rainwater is an excellent way to water cannabis plants with no need to be concerned about the water’s chemical content. Collecting rainwater is as simple as using large containers below water drainage points of a person’s house. Rainwater is cleaner than most public water supplies, but the container must be kept clean to avoid any contamination.
The Bottom Line
Regardless of how growers choose to water their outdoor plants, they should be sure the source of their water is clean and has a pH between 6.3 and 6.8. If the pH is too high or too low, the plant cannot absorb any nutrients. There are test kits available at most garden supply stores that will show a grower the quality of the water they intend to use.
Growers must plan ahead for how much water they will need during each stage of the cannabis plant’s growth, and what delivery method is the best option for their situation. Many growers require stealth, so choosing a quiet and discreet way to water their plants is essential.