Peat alternatives differ in characteristics such as water retention and re-wetting. East Malling Research is currently in the second year of a three-year Horticultural Development Company (HDC) project looking at the optimum irrigation guidelines for different substrates.
With the correct scheduling, there are a number of potential benefits to peat alternatives, including improved rooting, reduced plant losses and reduced moss and liverwort growth because the surface dries out quicker.
"The characteristics of other substrates are different to peat-based growing media and people often over-water," said Dove Associates managing director John Adlam.
"It's not that the product is inferior. You can't irrigate peat-free in the same way as peat and expect both to perform equally. Alternatives are often heavier, so even methods such as picking up the pot and assessing the weight need to be rethought."
The HDC research would provide good data to help growers make amendments to their growing regimes, Adlam added. The project is using a 75 per cent peat Sinclair product to represent industry standard, a Bulrush product of 50 per cent peat with wood fibre and bark and a Vital Earth green compost and bark peat-free products.