I think this is referring to living with a sick human/pet.
If you live with someone who is sick , having a sickness , or just being depressed and having bad energies , then that guy will affect the environment is living in.
Those are flowers they are not as impactful as the other things.
I think you should try to save the flower brother, keep it living for longer , and don't worry , even is dying it doesn't mean it's bad luck or anything like that. As an SS we should help things to live and prosper not to get rid of when it has served it purpose.
Man, I remember when I was a kid , I was so different back then, I was taking care of my flowers every day, cutting the bits which were dying and giving it water and honestly giving it love and affection and they were simply living longer and were so healthy as well. Try saving them as much as you can, I think this will be rewarded greater from the karmic universe as a reward instead of "Bad luck".