EXPERIENCE WITH A GRODAN-ROCKWOOL BASED SUBSTRATE FOR POT PLANTS

L. Hansen
The main ingredient in pot substrates at present is peat in various forms. The worlds supply of peat resembles the oil resource situation - concentrated at certain places and with limited supply of good and consistent quality.

Many kinds of additives to peat have been used by growers or compost manufacturers in order to stretch the supplies or to improve inconsistent quality.

It is well known that water repellant GRODAN granulate when mixed with peat based composts in various proportions to some extent can minimize certain problems like water logging and compaction. However, a compost based on water absorbant GRODAN granulate as the major ingredient has not yet been tested under normal, large scale growing conditions.

The aim of our trials was to prove that artificial media as a major ingredient of a compost in the future can be a valid replacement for peat based composts used in pot plant production, just as GRODAN succesfully has replaced peat/soil in vegetable and cut flower production during the last decade.

The basis for formulating a GRODAN granulate mix was taken from the following objectives which are regarded important from the practical aspects of pot plant growing:

  • the compost should be uniform and reproducable
  • the compost should have a stable texture and structure
  • the compost should have a good buffering capacity
  • the compost should have a good, predictable pore size distribution
  • the compost should be prefertilized and pH stable
  • the compost should be easy to handle

Due to the fact that GRODAN ROCKWOOL can be manufactured very uniformly and with great consistency the possibility of achieving most of the preset demands is possible.

Hansen, L. (1988). EXPERIENCE WITH A GRODAN-ROCKWOOL BASED SUBSTRATE FOR POT PLANTS. Acta Hortic. 221, 189-196
DOI: 10.17660/ActaHortic.1988.221.17
https://doi.org/10.17660/ActaHortic.1988.221.17

Acta Horticulturae