Adding horticulture quotes to your site from Quotes on Horticulture is incredibly simple. Just add this bit of code anywhere in your HTML code you want the quotes to appear:

<div id="qoh-quote">
    ... loading ...
</div>
<script type="text/javascript"
  src="http://quotesonhorticulture.com/js-api.php"></script>

The result is HTML Markup like this:

<div id="qoh-quote">
   <p id="qoh-text"There is nothing pleasanter than
spading when the ground is soft and damp.</p>
   <p id="qoh-author">
      <a href="http://www.quotesonhorticulture.com/author/john-steinbeck"> &mdash;
         John Steinbeck  </a>
   </p>
</div>

Each piece has a unique ID which should give you the CSS control you need to style the quotes however you like!