The lower leaves of some of my mums are turning yellow and have little black dots on them. Should I pull off the yellow leaves and spray with fungicide? Or is that just overkill? I was also planning on cutting them back so they remain bushy sometime this weekend. I'm trying to keep my garden looking nice, but I have 3 small kids and don't want to do the work if whatever is causing it isn't hurting the plant. Thanks in advance for all of your help. I'm a gardening newbie and this site is such a blessing!