Ostara aka Eostre is the Neopagan High Day associated with the Spring Equinox, and thus takes place on or near March 21st. We have no evidence that the ancient Celts celebrated this holiday, but we do know that in Wales the holiday is called Alban Eilir or Mid-Spring. Similar themes are shown to us throughout many cultures - acknowledgment of the lengthening day, the greening of the Earth, hares, eggs and special flowers to name a few.
The original feast of Oestre at the Vernal Equinox was a time for ritually blessing the fields and seed. If you wish to participate in the old traditions, try any of the following: Wear the color green, ritually plant seeds, draw water from a running stream before sunrise, dye eggs and decorate with magic symbols to exchange with friends and loved ones.
-Taken from The Wheel of the Year at Muin Mound Grove, ADF by Rev. Skip Ellison