I have heavy soil that holds water but even at that during a heat wave the ground will crack so I usually water, not new roses, over head for one hour as I do not always get to my largest bed.
I also more often than not, treat with bio-fungicide for Black Spot after that if the bed starts to show an infection.
I also use Cocoa Bean mulch putting it down at least two inches deep and will go feel under the mulch to see how moist it is at times.
For new roses I do the bowl around the plant and even with heavy soil, because I work it well when planting, I can put a gallon on a rose and 17 out of 19 times the water will not be standing within ten seconds, SO , I do stand and watch and depending on how fast the water goes away, will determine whether it gets a gallon or more.
