don't worry about it now, it is a new blog that is why it might be. once the Google bot does a few crawls, your pages/posts/tags will all be indexed properly.
though, your blog lacks a bit of seo. so here are a few things you can work on.
your read more tags are - /#more-183 you can use a better read more plugin to make those read more links seo friendly.
next, i see that you are using - ' in your titles. don't do that, just keep simple text on the titles.
i don't really like tags, but you can still keep the tags on the sidebar if you want them properly indexed.
also, you should us a "all in one seo plugin" and make sure to keep only the post/page/category/tags titles in the title. Currenly your titles are like Black | anythinggarden.co.uk, remove the url from the title.
don't worry too much, when you keep adding fresh content regularly and Google gives it a regular crawl, those meta descriptions start to appear properly.