With many soil mixes, plants run out of nutrients and start growing slowly after a few weeks. When a plant looks lime green all over (especially if bottom leaves are turning yellow and falling off), it needs more nutrients overall. The left plant received plain water and started turning yellow after the soil ran out of nutrients. The right plant has been receiving nutrients in the water and is a nice healthy green color.
Dyna-Gro Grow + Bloom is my favorite simple nutrient duo
Although you want to avoid discolored leaves for most of the flowering stage, it’s normal for leaves to start turning yellow the week before harvest.
Recommended Soil Nutrients
How to Adjust pH in an Organic Soil Grow (regular PH Up and PH Down can harm the natural balance of the soil)
Soils Starts Running Out of Nutrients
Multiple bottles at a time – Typically there are 3 bottles for the base nutrients but sometimes only 2. This class of nutrients needs all bottles at all times, which get mixed in different ratios depending on the stage of life. More flexibility to alter ratios throughout the plant’s life.
Summary of a Marijuana’s Nutrient Needs in Soil
Recommended Mineral-Based or Synthetic Soil Nutrients – This isn’t a comprehensive list of great cannabis nutrients, but these are the nutrient system I have experience with and recommend for growing cannabis.
How to Add Nutrients:
Loam has a dark color and is soft, dry, and crumbly when you hold it. Although it offers a tight hold on plant food and water, it drains exceptionally well. The air can freely move between the particles down to the marijuana plant’s roots.
The trouble with organic matter is that it gets depleted rapidly. This means you have to amend it on a season by season basis.
Buy Only the Right Soil for Your Cannabis Plants
Many soils will have a combination of at least two of the four types. Therefore, you can have sandy/silty, loamy/clay, silty/clay, and so on. If that isn’t confusing enough, there are different ratios of every soil type. It is an important consideration, however, because each one has its pros and cons.
This is a prevalent marijuana potting soil and has an almost neutral pH. It offers excellent drainage and water retention, contains high oxygen levels, and is naturally fertile. However, it is by far the most expensive option.
Once it reaches a height of 25cm, transplant the plant(s) to a container that is at least double the size of the first one. Once your plant hits the lofty heights of 80cm, move it to at least a 12-liter container. Once your plant hits a meter in height, you’ll need an even bigger box. This process continues until harvest.
Designed for indoor and outdoor cultivation, Happy Frog potting soil takes care of young cannabis plants’ essential needs, from correct pH levels to balanced nutrients, including a vital combination of microbes and fungi from earthworm castings and forest humus.
The best soils for weed don’t always have to be products specialized for cultivating cannabis. Sometimes, a good organic potting soil is all you need, and Sungro’s Black Gold all-organic potting soil is an excellent case in point.
Nature’s Living Soil Organic Super Soil
But just as important as what’s in this soil is what’s not: less perlite, less pumice, and fewer amendments. This makes Formula 707 a highly customizable soil, allowing you to add your topsoil and liquid nutrients at various growth stages depending on your cannabis plants’ needs.
Aurora Innovations Roots Organics Formula 707
Red’s Premium is another all-in-one, ready-to-use soil blend. But what makes it one of the best soils for weed is its stand-out feature: biochar. Biochar is an amendment that excels at protecting and promoting the growth of bacteria, fungi and other microorganisms that are essential for root development and strengthening your plant’s immune system.