Beltane
The Celebration of Beltane takes place on the 30th of April (Silver RavenWolf in "To ride a silver broomstick" cites the date of beltane to be 5th of May - perhaps it varies between different traditions)

It is a time to celebrate the union of the God and Goddess. Sexuality is celebrated at Beltane. It is traditional to light fires (Beltane means the fire of Belenos, who was a Celtic God) and jump over them. To jump the fire was to take the flame of life into yourself. Farmers would drive their cattle through the smoke to kill any parasites.

May poles are a potent symbol of the God. Love is also a strong theme of Beltane. And the wiccan equivalent of a wedding, Handfastings are often carried out at this time. In terms of agriculture the land is alive and vibrant.