I hope that when I reported that the Persephone Days were over, you didn't rush out to plant your spring vegetables.  Once daylength is longer than ten hours, surviving crops like kale will start growing again, but that doesn't mean the ground is warm enough for seeds to sprout. 

Lettuce, onions, and spinach can all handle soil temperatures as low as 35 while most other spring crops like the earth to have warmed to at least 40 degrees Fahrenheit.  I tested the soil temperature in the sunniest part of our garden last week, and the ground underneath our quick hoops was just barely 35 degrees, while unprotected soil was hovering right around freezing.

Most of the plants under my quick hoops are starting to grow again, but the tatsoi totally perished in the winter cold.  That means I had a spot just waiting to plant spring lettuce!  Rip out a few weeds, toss down a bucket of composted manure, then sprinkle on lettuce seeds, and the first garden bed of 2012 is seeded for March harvests.