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Five Tips for Soil and Fertilizer Management

soil and fertilizer management

Soil health is vital for plant growth, but soil and fertilizer management can be tricky – especially for beginners. Maintaining the right amount of essential nutrients and a proper pH level takes an incredible amount of effort and a strong knowledge of what’s best for your plants. 

Throughout the grow cycle, you’ll need to monitor your soil and adjust your growing practices accordingly. What can be most daunting about soil management is the fact there is no single answer about many aspects of soil health. Every type of plant is different, so there’s not necessarily a one-size-fits all answer. 

However, there are some general rules that can help you get started. Below, we’ll break down some of the basics of soil and fertilizer management to guide you toward a successful growing journey. 

Learn your macro and micronutrients  

Soil nutrients are of course vital to plant growth. Nutrient management means monitoring both the micro and macronutrients your plants need to thrive. 


Nitrogen, phosphate, and potassium are all considered macronutrients, often referred to as the “Big 3” of plant nutrients. You’ll often see NPK ratios listed on fertilizers, which refers to the varying levels of these three nutrients. 

Nitrogen (N) is the main component of chlorophyll, which helps your plants absorb energy, and also plays a major role in creating amino acids that build protein. 

Phosphorus (P) regulates protein synthesis, helps develop new tissues, stimulates cell division, and helps transfer energy throughout the plant. 

Potassium (K) helps control CO2 levels and also activates growth enzymes. 


There are multiple micronutrients found in soil, all of which work together to create a healthy yield. The main micronutrients usually discussed are calcium, magnesium, and sulfur. While used in smaller amounts by your plants than macros, they’re still important for growth and development. 

Calcium helps keep plant cells strong, magnesium stimulates chlorophyll production, and sulfur aids in the production of amino acids and proteins. 

While you won’t spend as much time adjusting micronutrient levels throughout your grow cycle, watching for deficiencies in key nutrients is important. 

Monitor Your PH Levels 

If you want healthy soil, it’s vital to measure pH levels throughout the growing process as pH has a substantial effect on micronutrients. If pH gets too high, this can result in micronutrient deficiencies. If pH is too low, iron and magnesium can quickly reach toxic levels. 

You can purchase a pH meter at a gardening supplies center or online. Wherever you buy one, make sure you check your meter every day and make swift adjustments if pH levels start to dip too high or too low. In general, you should strive for pH levels between 5.5 and 6.5 for optimal plant health. 

Raising and lowering pH levels is actually fairly simple if you act fast. 

You can increase soil pH by selecting a liming material. This refers to ground limestone products, which are usually sold at garden supply centers. You can buy pulverized, granular, pelletized, or hydrated limestone, although hydrated lime should only be used with caution as it can change pH levels dramatically. 

Aluminum sulfate and sulfur are commonly used to lower soil pH, which can also be found at garden supply centers. Aluminum sulfate can change pH instantly, while the effects of sulfur may take time. 

Adjust Your NPK Ratios Throughout the Growth Cycle 

Plants need differing amounts of macronutrients throughout the growth cycle, so you’ll have to adjust the fertilizer you’re using accordingly. However, it can get tricky as there are no hard and fast rules about the proper NPK ratios at various points in the cycle. A lot comes down to your grow environment and specific strain. 

As a very general rule, most people tend to avoid fertilizers during the seedling stage as seedlings are very fragile. Fertilizers, especially chemical fertilizers, can cause damage if used prematurely. 

As you move into the vegetative stage, higher levels of nitrogen and potassium are recommended with a medium level of phosphorus. As you move into the flower stage, it’s best to reduce nitrogen to a lower level while increasing phosphorus levels and maintaining high levels of potassium. 

Again, these are very general rules of thumb and not necessarily applicable to every grower. The best way to gauge proper NPK levels is to talk to other growers working with similar strains and be open to experimentation throughout the process. 

Watch out for magnesium deficiencies 

Any micronutrient deficiency can adversely affect plant growth, which is why conducting regular soil tests is important. However, magnesium deficiencies tend to be particularly common. If caught early, it’s easy to correct a deficiency and get your plants back on track to thrive. 

Magnesium deficiencies can cause yellowing on the lower leaves, which eventually leads to browning. If you notice this happening, it’s fairly easy to treat. Mixing two pounds of Epsom salts (magnesium sulfate) with 100 gallons of water can help restore adequate magnesium levels and reverse the adverse effects of a deficiency. The amount you’ll need to use depends on the amount of soil you’re using, so you’ll have to do some research. 

Practice proper watering techniques 

Finally, it all comes down to hydration. You can do everything right, but it won’t matter without proper watering techniques. If your soil is too dry or too wet, this will not result in a healthy yield. 

As with anything else related to soil and fertilizers management, there are no hard and fast rules about watering your plants. In general, you should water your plants when the soil feels dry up to your first knuckle or if your pots feel light. Usually, you should water your plants every two to three days. 

How much water you need depends on your plant’s grow stage, the time of year (if growing outside), the size of your pots, and a variety of other factors. Make sure to do your research carefully to ensure you’re watering your plants the correct amount. Too much or too little hydration can adversely affect almost every aspect of soil health. 


Soil and fertilizer management is vital for a healthy yield, but it can be incredibly complicated, especially as so much depends on highly specific factors. However, the above guidelines should give you a rough idea of the basics. 

Again, you’ll have to dive into specifics regarding your yield goals, strain, and growing environment to decide what’s best for your crops. A combination of scrupulous research and careful soil management practices will help your plants thrive. 

As always, we’re here to help if you have any questions! At California Lightworks, we want to help growers at all levels find success. If you want to know more about soil and fertilizer management or anything else, reach out here and someone will be in touch. 


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