I'm sorry for the delay in responding to your question.

Regarding the heavy clay soil. Generally, we do not recommend filling the planting hole with anything other than the existing soil (as poor as it is). But it is important to make a wide hole (wide at the top sloping to narrower at the bottom) to allow roots looser soil material to grow into. You can amend the soil a little with some organic matter but no more than 20%, unless you are planting a large bed of roses and choose to till up the entire area before planting. Then you could add an inch or two of organic matter and till it into the entire planting site.

Regarding full sun or part shade. You will likely see an increase in leaf diseases the more shade you have. They should be okay with morning sun and some afternoon shade but will not do well if its less than 6 to 8 hours of direct sunlight. Morning sun is key to getting leaves to dry out before disease can spread.

Regarding rose selection. My experience has been that shrub roses are much easier to maintain than hybrid tea. Knock Out roses have dominated the landscape for the last 10+ years but in our area Rose Rosette Disease has been tough on these. There is no cure so I would be cautious with Knock Outs. Other shrub roses are available and I don't hear about this disease being as common on those.

Finally, you might be interested in a webinar on "Getting the Most from your Roses" scheduled for July 10 this year. Details will be on this site: https://kentuckyhortnews.com/horticulture-webinar-wednesdays/season-five/ soon.

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