[John]

The results are in from a comprehensive trial of Bustaseed Seedling Trays with standard commercial seedling trays undertaken by Queen's University Belfast.

Full details here

[snowdrops]

I see the report says that Bustaseed trays are watered via the tray, which I think is the opposite for recommendations for peat free composts, I can report back on this further when here at Burbage Gardening Club, we have our second talk from Richard Cave from Melcourt at our November meeting. He will be presenting us with how to use peat free composts, but I’m pretty sure following my conversations with him previously they recommended to water from above and not to dunk trays & pots in water as is often recommended by tv gardeners and in gardening books these days. Might be worth contacting the University to ask this or for them to include the details of the composts used.

[John]

The report doesn’t mention watering, that’s my conjecture as to why the germination rate is higher. You can water Bustaseed trays from the top and soak conventional modules from the base.
Base watering of trays is a standard amongst professional horticulturalists and has been for some years. I hadn’t heard about not using the method in peat-free composts but note Melcourt Industries do composted bark products so maybe they don’t use coir (the commonest peat-free compost base) which probably works differently with regard to capillary action.
The report was produced by Queen’s University in Belfast which is in Northern Ireland and differs from the rest of the UK due to the EU settlement. So, they are free to use peat composts as are most of the EU. Ireland is a major producer and exporter of peat.
I’m hopeful that the current governments expressed desire to operate more closely to EU regulations could result in peat re-appearing in the garden centres.
I believe the composts used were peat, New Leaf and Pro-line which is a commercial organic compost.