February 19 is Usui among 24 seasons of the lunar calendar. Usui literally means “rain and water”, which indicates that precipitation from this season or later nearly always is not snow but rain, and that snow coverage will melt into water. Anyway, the season is surely changing from winter to spring.
In the tea ceremony, we normally put seasonal flowers at alcove. One of the flowers often used in this season is Fukinotou, a Japanese-origin plant, sometimes called a butterbur scape. This grass plant grows under the snow and can be seen once snow starts to melt (see the picture), so Japanese feel the atmosphere of spring when they see it.
As for seasonal seafood in early spring, Iidako (rice grain octopus), or Octopus Ocellatus in English is one of them. It holds a lot of eggs which look like rice grains in this season, that is the origin of the name of this creature. It is small and soft, so we often eat it simply boiled or deep-fried.