admin March 10, 2023
  1. Growing cactus is indeed a challenge, and were it not so, it would not have attracted the more serious-minded people, who are always ready to take up challenges.
  2. Firstly, it must be understood that any media is good, provided it can maintain a prerequisite set of conditions that your plant requires and for that you have to monitor the media along with your plant. Just as a good cactus can be ruined  by careless watering and spraying so can a perfectly good media be spoilt for further use.  Secondly, we as users fall back upon medias which can overlook our sins and neglect and continue to provide support to our alien plants which are from a far- far away worlds.
  3. Requirements of cactus media.
  4. Density: Not too high, not too low. If too high – pot is too heavy to handle. If too low the plants start tipping on planting and on growing tall.
  5. Porosity: Porosity is of two types :-
    1. Intergranular . This porosity is from grain to grain. This causes for the access water to flow through the media and drain out from the base of the pot. Incase the pot is holding water which does not flow out it will cause root rot. The roots will not be able to respire. No exchange of gases will take place. Also, such environment is congenial for growth of root nematodes.
    1. Intragranular. This perhaps is the most important aspect of media when we talk of “media being porous”. Media porosity actually means that media should be made of hard porous grains. Which means that the grain itself should have capacity to hold air and moisture by virtue of it having spaces. The root hairs grow into such spaces and can continuously respire and absorb moisture from the spaces within. These spaces also give place for useful microbes to grow which break down complex fertilisers into easily absorbable nutrients for the plant.
  6. Organic material. A little of organic material is required in each media. It can be leaf compost or cocopeat or residue from oil extraction etc. This organic material is a home for important life sustaining microbes. In addition, you can add your own mix of recommended microbes which are available off the shelf, such as PSB or Arbuscular mycorrhizae. You can fortify the mix with organic phosphate rich fibre material. This is available in the form of sterameal bonemeal etc. This is the key to the strength of your mix.
  7. Charcoal. Has water absorbing property. It has laminar structure. So, lot of unwanted chemicals which may be in water or your saturated mix, are attached to the laminar surface of charcoal. This lowers the pH of the mix or avoids the pH of the mix from going high due to accumulated salts in the mixture. Charcoal is light in weight and will cool the roots due to evaporative cooling. Presence of charcoal acts as a buffer for pH.
  8. Other Aspects of media. Media has to be refreshed or recharged periodically. Even if you do not use chemical fertilisers, the water itself due to its dissolved salts will raise pH of soil after some time. Therefore, you need to refresh the media or at least partially replace or wash the media from time to time. Remember it is not the nutrients which give a boost to the growth but the right pH which ensures that the plant can use the available nutrients. 
  9. Preparing medias at home. Preparing media is a simple task if you have the strength, youth, space, time, and resources available. Else, leave it to professionals. But just in case you wish to make media yourself just bear in mind the aforesaid factors and you will be able to get a mix your plants love. And they will surely tell you that. Just remember the following negative aspects of other substrates before you design your own perfect mix: –
    • Sand : Micaceous sand is not good it clogs the media. Blocks the water flow. Siliceous sand which has big grains is good for drainage but absorbs heat and is not porous.
    • Vermiculite and Perlite . These two substances are too light and tend to float on watering. Besides they have short life as they tend to convert into fine grained particles which become slushy. They are good for short life medias with cocopeat etc for seed sowing etc.
    • Cocopeat. Many believe cocopeat is not good for growing cacti. It is not so. The handling of cocopeat based media must be understood. When cocopeat is dry it is hydrophobic and while wet it is hydrophilic. So, you have to control watering accordingly so that it is not waterlogged all the time but also not too dry to reject water. Also, at the same time understand what affects the performance of cocopeat, factors like EC, Salinity Buffering etc.
    • Vermicompost. This causes clogging in the open spaces and because of its fine particles and muddy nature closes all avenues for water escape at bottom of pot. So avoid using it in abundance.
  10. Happy Planting and Growing!!!