Medical users

100x100 x 200. 120x120x200 (canil m o tor)


m i-iia

This cutaway drawing shows how the roots penetrate the soil. Note: There must be enough air trapped in the soil to allow biological activity and absorption of nutrients.


Phosphorous Potassium Sulphur Calcium Magnesium




Copper & Zinc



This pH Chart shows the Safe Zone is between 5.8 and 6.8.



Soil is made up of many mineral particles mixed together with living and dead organic matter that incorporates air and water. Three basic factors contribute to the cannabis root's ability to grow in a soil: texture, pH, and nutrient content.

Soil texture is governed by the size and physical makeup of the mineral particles. Proper soil texture is required for adequate root penetration, water, and oxygen retention and drainage as well as many other complex chemical processes.

Clay or adobe soil is made up of very small, flat mineral particles; when it gets wet, these minute particles pack tightly together, slowing or stopping root penetration and water drainage. Roots are unable to breathe because very little or no space is left for oxygen. Water has a very difficult time penetrating these tightly packed soils, and once it does penetrate, drainage is slow.

Sandy soils have much larger particles. They permit good aeration (supply of air or oxygen) and drainage. Frequent watering is necessary because water retention is very low. The soil's water- and air-holding ability and root penetration are a function of texture.

Loam soil is ideal for growing cannabis. It contains a mix of clay, silt., and sand. The different sized particles allow a large combination of pore spaces, so it drains well and still retains nutrients and moisture.

To check soil texture, pick up a handful of moist (not soggy) soil and gently squeeze it. The soil should barely stay together and have a kind of sponge effect when you slowly open your hand to release the pressure. Indoor soils that do not fulfill these requirements should be thrown out or amended. See "Soil Amendments" below.


The pH scale, from 1 to 14, measures acid-to-alkaline balance. 1 is the most acidic, 7 is neutral, and 14 most alkaline. Every full point change in pH signifies a ten-fold increase or decrease in acidity or alkalinity. For example, soil or water with a pH of 5 is ten times more acidic than water or soil with a pH of 6. Water with a pH of 5 is one hundred times more acidic than water with a pH of 7. With a ten-fold difference between each point on the scale, accurate measurement and control is essential to a strong, healthy garden.

Cannabis grows best in soil with a pH from 6.5 to 7.0. Within this range marijuana can properly absorb and process available nutrients most efficiently. If the pH is too low (acidic), acid salts chemically bind nutrients, and the roots are unable to absorb them. An alkaline soil with a high pH causes nutrients to become unavailable. Toxic salt buildup that limits water intake by roots also becomes a problem. Hydroponic solutions perform best in a pH range a little lower than for soil. The ideal pH range for hydroponics is from 5,8 to 6.8. Some growers run the pH at lower levels and report no problems with nutrient uptake. The pH of organic soil mixes is very important because it dictates the ability of specific pH-sensitive bacteria.

Measure the pH with a soil test kit, litmus paper, or electronic pH tester, all of which are available at most nurseries. When testing pH, take two or three samples and follow instructions supplied by the manufacturer "to the letter." Soil test kits measure soil pH and primary nutrient content by mixing soil with a chemical solution and comparing the color of the solution to a chart. Every one of these kits I have seen or used is difficult for novice gardeners to achieve accurate measurements. Comparing the color of the soil/chemical mix to the color of the chart is often confusing. If you use one of these kits, make sure to buy one with good, easy-to-understand directions and ask the sales clerk for exact recommendations on using it.

Continue reading here: Peat Lite Mixes

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