Question
20 foot long 4 foot wide flower bed filled with salvia, vinca, marigolds and petunias everything is growing great except petunias have replanted 4 times i give up there healtly plants and look great in bed and with in 1-2 weeks they wilt turn yellow and they dead i have never had this problem before all in same bed the other plants are fine just petunias i dont get it can you help  after about 20 plants i have one left you would think other plants in same flower bed would be having problems but they are not PLEASE CAN YOU HELP

Answer
Darlene, there are certain fungus diseases that are unique to petunias. The one common disease that is prevalent in many home gardens is a soil borne disease called phytophthora root disease. This is a fungus disease that attacks the roots of petunias, but is harmless to many other annuals.

Unfortunately, this disease can live in the soil for many years. My advice would be to avoid planting the petunias directly in this particular bed. If you still want to grow petunias, consider placing containers in the garden. Just be sure to fill them with a ferile potting soil.

If you wish to eradicate the disease, the only proven method is solarization. This is accomplished by covering the soil with black plastic for three months. The heat will kill the disease, but the downside is that the bed cannot be used for planting the summer the soil is being solarized.

I hope this answered your question. Good luck, and please write again if you have any more questions.

Regards,

Mike