Know Before You Go
This park is up a hill, so be ready to walk uphill and up some stairs if you aren't going by car. There is a small flat section of road on Taylor Street where it crosses Vallejo (which doesn't really make its way up because there is a park there, but there is a sign for it). Enter the park from this flat, and choose the left entrance. After not too many steps on this path, you'll see the Poet's Corner on the left.
If you keep going downhill through the park (after you've read or written some poetry) to enjoy some more lush gardening and another little secret in the park to discover. (Interesting side venture if you want, across the flat from the park is a stairway that looks private but isn't, and it takes you to the top of Russian Hill, a cul-de-sac with magnificent homes.