Bonsai Potting Mixture

Bonsai are grown in pots and therefore have a limited space from which to aquire water and nutrients. Unlike plants which grow in nature or in your garden, your bonsais' root system cannot obtain water, nutrients or air beyond its containers walls.

___________________________________________________________________________

When selecting a suitable medium for potting bonsai, there are certain criteria that your mix will need to meet. It must be able to retain water and nutrients for your tree to grow and provide adequate airspace for drainage to prevent water-logging. To achieve this balance, one must find the correct mixing ratio of organic and inorganic matter.

'Good' water retention is important because it will keep the soil moist between waterings. This is crucial because the trees roots require moisture to survive. Too much water retention however, can become extremely damaging to the tree.

For this reason good drainage is necessary. Your potting mixture must allow for all excess water to drain from the pot immediately. Soils which lack good drainage become too water-rententive and therefore lack aeration and tend to cause a build up of salts.  Water-logging can also lead to root-rot.

It is also critical to the survival of the root system that it has access to sufficient amounts of oxygen. For this reason aeration in the soil is necessary. To allow for aeration there must be enough space between particles to allow for tiny air-pockets.

___________________________________________________________________________

Although all trees require free-draining, water-retentive soils, different species have different water and nutrient requirements. Therefore there is no 'one-fits-all' soil composition, which makes describing the perfect soil mix for your specific bonsai an impossible task.

A good example of this is that Junipers and Pines require significantly less water than most other species and therefore require a less water-retaining soil mix. Alternatively, flowering and fruit-bearing species require a lot more water and should be potted in a higher water-retaining mix.

Adding course, inorganic matter, is an efficient and suitable method of achieving better drainage for those Junipers and Pines. Increasing the amount of organic matter in the mixture allows for a more water-retentive composition but becomes risky as it can lead to water-logging.

Every individual bonsai artist will have to discover which mixture works best for each of their individual species. This is why making your own potting mix becomes so much more economical and beneficial.

___________________________________________________________________________

Try to find someone in your local area who is also a bonsai enthusiast and find the potting mixture that works best for them. Alternatively, contact a bonsai nursery and find out what potting medium they would recommend you use, in your region.