I had the same issue, and since this post is one of the first results that comes up in Google, I wanted to share the solution that I found.
The code that Christine provides is good, but the problem is that you shouldn't generally edit the header.php
file directly, since your changes would be erased when you update the theme.
The solution is to insert the code into your own plugin, and to use an action hook in order to insert the description into the header:
<?php
function add_meta_home() {
if (is_home() || is_front_page()) { ?>
<meta name="description" content="Lorem ipsum dolor sit amet."/>
<?php
}
}
add_action('wp_head', 'add_meta_home');
?>
The use of (is_home() || is_front_page()) ensures that the meta description displays for your website's homepage, regardless of how it's configured.