My main site which is an eCommerce sales site have a blog in order to outreach more customers in a sub-domain of the root directory. But sometimes it may be for the main site's traffic the blog takes too much time to load. How can I speed up the loading speed? Anybody any suggestions.
If you are sure that its the main site's traffic which is causing the trouble then you might have to contact your hosting company upgrade your hosting plans. As it is the only answer and if still the problem remains than change the hosting company.
It seem that your site is fine the hosting company is getting you trouble. Contact them. And also in the mean time clear out your cache data.