Customize Genesis search input and button.

functions.php

<?php

add_filter( 'genesis_search_text', 'custom_search_input_text' );
/**
 * Customize the search form input button text.
 * 
 * @param string $text Existing input text.
 * 
 * @return string Amended input text.
 */
function custom_search_input_text( $text ) {
	return 'Search my blog';
}

add_filter( 'genesis_search_button_text', 'custom_search_button_text' );
/**
 * Customize the search form input button text.
 * 
 * @param string $text Existing button text.
 * 
 * @return string Amended button text.
 */
function custom_search_button_text( $text ) {
	return 'Go';
}