I have two barrels that I planted a bunch of mixed freesia bulbs in last year. They sprouted in late spring but only the yellows bloomed (there are five colors). Now the freesias started coming up again but I've noticed on some of them there is what looks like rust on the edges of the leaves. I'm not sure what it is but when they had this discoloration they didn't bloom last time. Am I missing some sort of crucial vitamin for freesias or might this be a disease from poor bulb stock?...I did buy them at Lowes. Any input will be appreciated! Thanks!

~Rose