newly planted roses turning black at stem
planted new rose bushes 21 doing well 1 ok other 2 steam is turning black seen grubworms while planting help
If the canes are turning black, they could have grub worms attacking the root systems. By the time the stems turn black, it is usually too late to save them. I would recommend planting new roses in those areas and add some Bayer Tree and Shrub granules to the planting soils. This product is a systemic product that will kill the grub worms and protect the roses from other diseases and insect attacks. You could try adding the granules around the rosebushes effected and water in well. Spray the canes and any foliage down well with a good fungicide listed to treat Canker. You may be able to get them to come back but I must tell you that it can be a frustrating battle that ends in having to dig the rosebushes out and replace them anyway.