In my experience, the leaves on blind growth age quickly, and sometimes are "ground zero" for spider mite infections.

But even on "real" canes, leaves DO age. Eventually, they yellow, and fall away. I don't see any disease here. Just foliage that needs to go bye-bye. :-)

Jeri

There's only one sort of rose that does not age and change in this manner: R. plastica.

For the rest, they are living things. There's nothing wrong there.

Jeri

Also not sure why the Ironite was needed.

Don't add iron unless the new growth comes in pale with green veins.

Areas of crowded undersized leaves that are not producing strong shoots and bloom indicate that the cane should be cut back to healthy wood.

I agree that the yellow leaves are just senile leaves with no signs of disease.

I've alway felt that they probably need to be properly pruned, but have heard that knockouts don't really need that. That said, I do believe that there is a lot of center growth that should be cut out, but I just don't know how to do it for sure.

99.9% of the time, the plant is going to rebound from what you do with your pruning shears. Try not to cut more than a third of the total plant off and you really can't severely hurt it. But, every green leaf you remove is one less in the total required to produce the color display you're expecting. Those out on the streets probably perform differently from yours because they receive more heat...reflected from the asphalt and concrete they grow near and radiated long past the time the sun moves off those surfaces. I would expect them to probably flower more heavily than yours in a garden setting because to the street plants, it is a much hotter "climate" than your cooler beds. The hotter roses may also not experience as much potential disease and insect attacks as yours might, for the same reason. Where they are, it is significantly hotter and probably drier because that reflected/radiated heat dries the surrounding air, making the conditions less favorable for bugs and fungi.

Comparing your Knock Out in your garden bed to the ones growing as street or parking lot plants is quite difficult because all that solar collecting hardscape probably makes a full zone difference in heat. Kim

IMO, your observation concerning the shallow root systems may very well explain the yellowing leaves. It's difficult to give advice on watering without knowing the soil conditions. Considering that you garden in the sunny (often sultry) South, however, I think there's a VERY good possibility that your ongoing problems with yellowing leaves is indication that the roses are not receiving enough water. Any plant having shallow roots is going to require more water, especially where heat and intense sun are facts of life. If you increase your watering regimen now, you might avoid the extreme loss of leaves that you experienced last season.

Based on the foliage in your photos, I agree that the use Ironite is not warranted -- at least not on a routine basis.

Just do that once after the spring bloom--and you will be surprised how much better the landscaping looks.

It is possible that after the next bloom cycle, you may have to repeat that process.

Just think of it as routine housecleaning in the garden.

Kate