Hello everyone, I am a new to gardening. I planted a few cosmos and one of them looks like it might canker disease or it could be something else. I've read up to terminate the plant ASAP. But the damage is only on the flower not on the stems nor at the root. Any suggestions as to what I can do?I have 3 Cosmo plant planted on the same pot. Should I also remove all of them if the flower is infected?
