The importance of proper soil moisture in cannabis cultivation is crucial to a healthy plant and the quality of buds. It also helps control fungal infections like bud rot and mould.
The substrate you use will have the most important influence on how easily your marijuana roots can extract water. The air porosity and water holding capacity of the material will determine how easy or difficult it is for your roots to extract that water from the substrate.
Soil Moisture
Soil moisture is one of the most important factors in achieving the optimal growing conditions for your cannabis crop. The correct amount of moisture allows plants to thrive, but too much can result in plant rot and other problems.
The ideal soil moisture for a cannabis grow is slightly moist, but not wet. Soil that is too wet can lead to root rot, nutrient burn and other ailments, which can significantly impact your production.
There are several different ways to measure soil moisture. A soil moisture tester is a common tool, but there are other options that can provide more insight into the moisture content of your soil.
One popular method of measuring the moisture content of the soil is through a method known as the wet weight of the soil. This measurement uses a sample of dry and moist soil to calculate the total water in the soil.
Another way to measure the water content of soil is by the soil water potential. This measurement is measured in units called bars, and a bar is equal to the force of a single atmosphere.
In general, the drier the soil, the higher the water potential and the harder plants must work to draw up and use water.
Soil water potential is a critical element in the proper growing of cannabis because it affects how easily a plant can take up moisture from the soil and how well it can survive drought. Typically, the optimum soil moisture potential for cannabis is about 120-150 mbar (mbar = a unit of pressure) in the vegetative stage and 150-180 mbar in flower depending on the strain.
A good soil for cannabis cultivation should contain a high percentage of organic material that is broken down by fungi and bacteria over time, as opposed to chemical slow-release nutrients. Many growers choose a heavy composted, “super” soil that is enriched with amendments such as bat guano, worm castings, dolomite limestone and coco fibre, among others.
Perlite and vermiculite are also commonly used by growers to improve the drainage and aeration of their soil. They are both lightweight and porous materials that improve the texture of the soil and help it retain moisture. However, they are not as effective as organic amendments in improving nutrient retention or soil structure.
pH Levels
When growing cannabis, it’s vital that you maintain proper pH levels. This will determine the growth and nutrient absorption of your cannabis plants, as well as their future harvest.
pH is a scale that reflects the ionic state of compounds in a solution, with acids at their extremes and bases at their neutral point. It is measured on a 14-point scale, from zero (most acidic) to 14 (most basic).
The best way to keep your pH level in check is to use a pH tester. These devices can range from inexpensive pH strips to a digital meter that you insert into your soil or nutrient solution to read its pH level.
A pH tester can be a valuable tool in your cannabis cultivation arsenal, especially as it allows you to spot potential issues before they turn into larger problems and affect your final product. It’s also a good idea to test the pH of your water when it’s in your reservoir, before you add it to your grow area, and a couple of days after you’ve fed your plant.
One thing to note when testing the pH of your water is that it can change over time, and as a result, your readings may be off. This is especially true for if you’re using rainwater, which has different pH values depending on the location and pollution levels.
Similarly, your soil pH can change as the nutrients in it break down and the water that it holds changes in temperature. This makes it essential to monitor your soil’s pH level regularly, ensuring that it stays within a safe range of 5.8 to 6.2 for hydroponic grows or 5.5 to 6.5 for soil-based or organic-only grows.
While some marijuana growers don’t bother with pH testing, it is a critical component of your cannabis cultivation. It will help you avoid nutrient lockout, which is when your plants cannot absorb the nutrients they need to grow properly and may even die from starvation. The first signs of nutrient lockout are stunted plant growth, yellowing leaves and poor fruit production.
Drainage
Soil moisture and proper drainage are crucial for the health and vitality of your cannabis plants. When the soil is too wet, it can drown your plants and cause them to die early on. The plant may also become prone to diseases and pests that will attack the roots. If your soil has poor drainage, you can waste a lot of money on water and fertilizers as well as end up sending plants that are weak and with unhealthy roots to the retail market for sale.
When you’re growing your cannabis in a container, you need to make sure that there are holes at the bottom of the pot for excess water to escape from. Otherwise, your plants will sit in a pool of stale, nutrient-laden water that can lead to mold or other fungal problems as well as slow growth rates and nutrient deficiencies.
You can check the drainage of your soil with a percolation test. This is a simple process where you dig a hole in the soil and allow it to drain out of the pot.
If the soil is too dry, you should water your plants regularly to ensure they have enough moisture for their roots to thrive. This can help prevent nutrient deficiencies and improve growth and yields.
Soil is generally comprised of rock or gravel, sand, silt, and clay, which all have different drainage properties. Soils with a high gravel content tend to drain more quickly than sandy or silty soils.
Coco coir, on the other hand, has a much better drainage capacity than soil, which is why it’s one of the most popular growing mediums for cannabis. However, it’s important to mix it with a good amount of perlite in order to aerate and improve drainage. The best ratio of coco coir to perlite for aeration and drainage is 70-30.
A properly drained soil will keep your plants healthy and thriving throughout the entire growing process. It will also help your plants to produce higher yields, a faster flowering rate, and stronger buds. The right type of soil can help you to avoid a host of growing problems, such as overwatering, nutrient deficiencies, and plant fungi that may harm your plant’s health and productivity.
Nutrients
During each stage of your cannabis’s growth cycle, it needs the proper nutrients to thrive. Keeping a steady supply of nitrogen (N), potassium (K), and phosphorus (P) in your soil can help your plants produce stronger roots, healthy leaves, and robust buds.
Nitrogen gives your plants energy to grow and helps synthesize proteins, amino acids, chlorophyll, nucleic acids, and enzymes. It also supports overall plant growth by controlling the opening of stomata or pores on leaves to allow for water and salt transport.
Phosphorus is another nutrient that’s vital for your plants, as it promotes rigid growth during the vegetative stage. It’s also important during flower development, as it allows your plants to absorb more oxygen and water.
Potassium (K) is another essential nutrient for your cannabis, as it regulates water and salt content in the soil. It can also activate dozens of key enzymes that control sugar transport, N and C metabolism, and photosynthesis.
Most cannabis-growing potting mixes provide the nitrogen and potassium your plants need during germination, although some contain other nutrients. These include a slow-release organic nutrient or a fertilizer that can be used from seed to harvest.
Many growers use a mixture of compost and soil to create their own “living” soil. Compost contains beneficial microorganisms that break down nutrients and release them gradually into the soil. The addition of worm castings or mycorrhizal fungi adds even more nutrients and bacteria.
pH testing is also a must to ensure your growing medium’s ideal level of acidity or alkalinity. This can affect the odor and flavor of your finished cannabis crop, as well as the quality of your flowers.
The optimum concentrations of each of these nutrients will vary depending on your growing medium, and the cultivation techniques you choose. But all of them are necessary for your plants to grow healthy and productively. Having a good understanding of your plant’s nutrition requirements during each stage of its growth cycle is key to maximizing your harvest and achieving the results you want.
