Natural methods of keeping Roses healthy

Just wondering how people keep their roses healthy?

I spray mine once a month with Rose Clear, but I don't like using it because it has nasties in it which could kill beneficial insects.

If I spot an aphid infestation, I either squish them or else spray the plant with soapy water, which seems to do the trick.

I am thinking more of the numerous other diseases which can affect roses, such as powdery mildew, black spot, etc. What can I use as a natural spray to prevent/combat those?

I have read about using baking soda - has anybody used that and does it work?

Are there any other 'natural' things I could use?

Thanks in advance