Each resource island usually needs water for the year. We usually use a
microsprinkler, rainbird or MP-rotator to water a full circle and we
put the fence line where the circle of water covers. If the circle is
larger than 50 foot the deer will jump into the enclosure and actualy
live in the 'safe house'. If you like to gamble, you can try these
without irrigation, on wet years they will or just fine. On dry years
you will lose the entire planting.
The resource island should include a mixture of pioneer and secondary
pioneer plants from you area. Here are a few lists for different areas
of California. Use at least 5 species in each island.