Clay

Clay is a fine grained amendment that can store a significant amount of water. It should be used to amend the soil of mostly older plants, like palm trees, oleanders to increase the water storage capacity of the soil. If you are adding clay to the soil make sure it does not amount to more than 1-2% of the soils total volume.

Pine bark mulch

The mulched bark of black or Scots pines is usually added to the soil for plants preferring a more acidic environment and whose roots require more air – e.g. ferns, bromeliads, and some orchids that need an airy, loose growing medium.

Pine bark decomposes slowly keeping its beneficial qualities for a long time.

For orchids choose a mulch with 3-4 cm bark pieces, for bromeliads and ferns with 2 cm ones.

Pine mulch should only make up third of the soil at most.

River sand

River sand is a clay free, fine grained mineral material. We use it to create an airy growing medium and help the drainage of excess water.

River sand is mostly used at propagation by cuttings or when rooting slips in a ratio of 1:10 or 1:20. River sand can be mixed into the soil of cacti or citruses.

Peat

Peat is one of the most common soil amendments since its fibery structure improves the consistency of the soil dramatically. It’s always worth supplementing the growing medium of azaleas, ferns, bromeliads, palm trees and orchids with peat in a ratio of 1:4 or 1:2.

Apart from its acidic characteristic it also makes the soil more airy plus provides the plant with some extra nutrients.

Cow manure

Composted cow manure is one of the richest nutrient sources for plants. It is important that you never mix fresh manure with the soil since it can burn the roots of the plants. Always go with the composted version found in stores. Composted and dehydrated manure is dried and composted for at least a year before it is marketed. The ratio of manure should not exceed the third of the full volume. This will provide your plants with much needed nutrients. Make sure not to supplement the pot with further nutrients for a month or two after planting.