The summers can get hot during a heat stroke (above 30°C for a week have been reported in the last decade), but are usually around the 20°C. So even though this is a temperate climate, we have had dealings with extremes. This winter for instance we barely had a few days snow, but then again it has been very wet (not good if you garden on clay soil). So best I'd plant them in full sun at this latitude.
Besides, I can't believe it would be a nutrient deficiency. I've been fertellizing the second week they sprouted with a liquid feed and never let the potting mix dry out.
