Greenhouse growers know that in order to achieve optimum nutrient availability for plant growth, the growing medium's pH for most crops should be in the 5.5-6.5 pH range. The standard base components in most soilless media, peat moss and composted pine bark, have a pH in the range of 3.5-5.0.
This is too low for most crops and requires the use of limestone to bring the growing medium's pH up into the ideal range.
The quantity and choice of limestone used to increase the growing medium's pH is a function of several factors, including:
- the growing medium's components;
- the type of limestone;
- the particle size of the limestone used.
Read more at PRO-MIX