Mums don't look good - what gives?

I've been keeping water on my mums, yet the blooms are drying up and dying before new, fresh blooms can take their place.
Can I over-water? Might I be under-watering? Any help?
Thanks!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.