Experiment

A few weeks back I watched a short series with Jimmy Doherty doing some of Charles Darwin's experiments again. This gave me an idea - set up a little experiment to compare how seeds fare in peat and peat-free composts. So ten days ago I finally got round to setting this up. There are four 6-module trays, one New Horizon Peat-Free multi-purpose, one peat (this was from a bag left at the allotment which we thought we might as well use), one our garden compost, and one a brick of coir from a pound-shop. All except the coir were sieved. I planted the same number of seeds in each module: lettuce, chives, radish, tomato, parsley and basil, aiming for a range of plant types and a range of seed providers.

This is how they are doing today:


The experimental modules are the four in the forground. From left: coir, peat, garden compost, New Horizon. They are all kept in the same place and treated the same. The radishes are all up, some lettuces are appearing, and some basil just germinating.


New Horizon


Garden compost


Peat



Coir

So far, slightly to my chagrin, the ones in peat have germinated slightly sooner and look slightly larger and greener. New Horizon and garden compost look about the same, and coir is catching up after seeds were slow to germinate. But this is meant to be a long-term experiment, and not all the seeds have even germinated yet. I am making records every few days and will carry on until the seedlings need to be planted out (or dispensed with in the case of the radishes).

Also, my experimental method may have been at fault. Just a couple of days later there was a Gardener's World Special, 'For Peat's Sake' which described why and how to use peat-free compost and showed gardening WHICH's much larger and better experiment. I realised that by treating all the media the same, I could have been giving peat an advantage. Coir, home-made compost and compost from wood waste and municipal waste all need mixing with sand or vermiculite to work at their best, which is how I usually use New Horizon (incidentally their best buy). So I shall have to set up a further experiment... when there is space...