Hi Raymond,

Sorry to hear about your roses. Roses as I am sure you know can be tricky, requiring lots of son, good drainage and organically rich soil. They are also susceptible to a variety of diseases - black spot, powdery mildew and rust (a fungus - most common in summer) being the most common. 

It is hard to tell what is ailing your current roses, but it does look as if you have some quite healthy new growth already appearing. The image of what looks like a Texas Knockout  seems to be a rose that is very much in need of pruning - particularly to remove some of the dense central growth and spindly branches.

Since roses are semi-dormant in the winter, they can start to look pretty sick by this time of the year, before putting on their new spring growth. I would recommend heavy pruning to remove any dead branches, diseased foliage, and to just reshape the bushes. This is the time to prune, perhaps right after this cold snap, but do not leave it any later as you already have new growth appearing. You may find that the new growth comes in fresh and healthy. (If you have not pruned roses in the past, there are many U-Tube videos that show the right and wrong ways to prune.)

Common Rose Diseases in Central Texas 

Unfortunately, our hot humid climate is ideal for the development of several diseases that affect roses. These include blackspot and powdery mildew.

Blackspot–the most troublesome disease of roses in our area

Blackspot (Diplocarpon rosae) is the most devastating and widespread of the rose diseases. This fungus attacks practically all of our modern rose cultivars, but there are numerous wild roses which are left untouched! Regular spraying can control blackspot as can care when watering not to get water on the leaves.

Powdery Mildew–another widespread disease of rose

Powdery mildew (Sphaerotheca pannosa) is another widely distributed and serious disease of roses. Young tissues are the most susceptible and the disease is typically diagnosed when white, powdery patches of fungal growth appear on young leaves. These leaves will often fold inward or become twisted and distorted. New stem growth and flowers can also be attacked.

You can also find more information on rose diseases at the link below:

https://plantdiseasehandbook.tamu.edu/landscaping/shrubs/rose-2/

Liz Stansfeld
Travis County Master Gardener