Skrev en rapport på EPS tidigare. Är för lat för en till på svenska så här kommer en copy/paste:

As an experiment I decided to sow a few thusands Trachycarpus Fortunei Bulgaria seeds into the ground in two different patches. One were left completly unprotected while the other got a blanket thrown over it. The unprotected patch was however partly sheltered from winds from the west and that seems to have made a huge difference when you look at the results as half of the seedlings got severely burnt.
The winter were mild to begin with, but as you know it got really cold in febuary with a minimum temperature of -18c and about 20 days of constant freeze. Another thing to note is that during the -18c there were no snow to protect them.

My bigger trachy which were protected with a minigreenhouse suffered no damage from the cold. I think the the sun might have helped a lot since it was sunny during the coldest days.

Here is an album of the unprotected seedlings and the bigger trachy. Notice how different the damage is. This seedling patch is about 1 square meter: