Posted on 28th Jun 2012 @ 10:37 AM
As our inventory of soil and soil-less media grows, it gets even more confusing to the average grower as to which one to choose, so I have decided to add a brief description of each one, along with some recommendations for the use of each. Follow the links to read the full descriptions. I hope this helps make choosing the right dirt easier for all of you.
Let's start with a list of basic Plant Growth Stages: seedling and newly-rooted cuttings, early vegetative, mature vegetative, and fruiting/flowering. At each stage in a plant's life, certain soil and fertility conditions must be met, or avoided, to ensure healthy growth. If the media is inert (contains no nutrients), the plant suffers from nutrient deficiencies, and if it is too hot (contains more soluble nutrients than a plant can handle), it suffers from luxury consumption and shows stress in the form of burning or leaf-curling, among other signs.
NOTE: Not all Soil Mixes are Available Online
The following is a list of recommended soils for each growth phase:
Seedlings and Newly-rooted Cuttings
If using Pro-Mix, Sunshine Mix, Black Gold or B'cuzz HydroMix, additional nutrients must be used one week AFTER the first set of true leaves develop on seedlings. If using rooted clones, additional nutrients must be added prior to planting or shortly after. FoxFarm Light Warrior usually contains enough nutrients to sustain healthy growth for up to two weeks, and Ocean Forest, Pure Earth, and Manna Mix support growth for up to a month. It takes experience to learn exactly when nutrients should be applied, as you are trying to stay between the lines of not enough and too much.
Early Vegetative Through Fruiting/Flowering
All of the mixes appropriate for the seedling/cutting stage may be utilized throughout the plants entire life, but will need to be ammended with additional nutrients, whether it be a top-dressing of powdered or granular fertilizers, or through a regimen of using liquid, water-soluble fertilizers every other watering or so. It is up to you to choose which method is appropriate for your specific grow.
Air to Water Ratio? What Does That Mean to Me?
This ratio represents the water holding capacity of a given mix. The higher the air to water ratio, the less moisture the media holds, and the more often you will need to irrigate. It also means roots don't have to try so hard to break up the soil to expand, so, typically, the higher the ratio, the easier it is to get a BIG root system. Every mix has it's advantages and disadvantages. Low air to water ratio is not a bad thing in the right situation. If you are having problems with plants drying out too quickly, for instance, you should use a medium that holds more water. Outdoors a low air to water ratio can be advantageous if your growing season is hot and dry.
posted by kevin