Cold Caithness growing season added to by compost challenges
Gardening on the Edge by Diana Wayland
This growing season was undoubtedly a struggle. One reason was the dreadful summer. Much of it was cold, wet and windy. Yet while many plants struggled in the garden, others did well.
The other reason was the bought general purpose compost, now peat-free. Undoubtedly its performance differs from that of the old peat-based ones, which has taken me a bit of getting used to.
Consequently I had difficulty germinating seeds, getting them to grow, and to grow on after pricking out. I found extremely long roots while pricking out, as if the seedlings had searched desperately for nutrients, and these were unavoidably damaged during pricking out.
Combined with the chilly growing season, it resulted in young plants going out later than usual.
One major difference in the performance of the peat-free composts is that, unlike peat-based ones, they do not transfer water around the container, resulting in a single pot or tray being both bone dry and soaking wet.
After watering a planted tub that had got dry, I watched the water just pour out of the bottom right below where it had been watered in. After that I started introducing coir to the peat-free composts.
Coir is coconut fibre. Some might argue that it is not environmental to import it as such transport is still fossil-fuelled. In which case they need to stop consuming anything that we do not grow here. An impossibility. I buy it compressed and dehydrated, then rehydrate it for use. While not as good as peat for water management, it is better than not using it, and at least it is a sustainable resource. Easier to rehydrate than peat, too.
Another major issue was germination. It was slow and erratic, once I switched to the peat-free seed composts, as compared to the peat-based ones. And when seeds did germinate, they just sat with only their seed leaves and took weeks to start to grow their true leaves. As that is the point at which you start to feed them and prick them out to larger containers, it was a problem.
Seed composts contain few nutrients. However, I found that by adding a little seaweed meal slow-release fertiliser when sowing seeds I got better, faster germination, and they soon grew their seed leaves.
I now add the seaweed meal to any potting mixture I make up based on the bought peat-free composts. The results have been astonishingly better.
The final bit of gold I now add to my made-up potting medium is sieved garden compost. It has improved potted plant growth and health beyond comparison. I only have to add a little to each mixture, along with the seaweed meal and the coir.
I discussed making garden compost a while ago. It is quite easy and there is lots of online information. It is so beneficial that we have had to double up our compost bins!
I would love to make all my potting compost from scratch, but as I use so much during the season, I have nowhere to store the components even if I could access some (such as sterile soil) in the quantities required. So I have to buy commercial ones as required through the season.
Peat-free composts perform differently to peat-based. While this can be challenging, experimenting and developing ways to rise to that challenge can bring as good results as before.
