I don't know where you are located.... but moisture/humidity is a big contributor to mildew and black spot. Anything you can do to keep your roses in full sun, open to air flow and mulched will help. Gardengal is right, the best control is to spray in front of the problem.

Location has a lot to do with disease susceptibility. The over-all best way to keep your roses healthy is to grow them as well as you can: good soil, lots of organic matter, adequate watering.I gave up spraying because it was just too much work, and didn't seem to do much good either. I don't miss doing it, that's for sure, and my garden doesn't seem to miss it either!

It's true that it is best to grow "only disease resistant varieties",but I totally agree that there are some roses one just loves too much to be without. Mine would be Climbing Old Blush.It tends to go through a phase of being "ghastly" every year after it's spring flush; I think it's just because it never takes a rest in my climate (I have 5, of various ages; the oldest one has flowers on it even now). By the end of spring it is just tired, gets leaf fungus,drops all its leaves (it did this even back in the days when I used to spray) Then they all grow back, so by mid-summer it's leafed out again. I'm approaching this problem in two ways: one, I'm going to try feeding it a LOT more before the spring flush. Two, I've just planted a clematis montana with the oldest one. The clematis can "cover" for the rose when/if it needs to go through it's ghastly phase.

Bart, your Old Blush just sheds its old leaves in late spring as part of the natural process of foliage rejuvenation, it being genetically extremely evergreen in a mild climate. Leaves in the process of being shedded do get attacked by fungi, that's true with most plants, which help in the shedding process. It's all pretty natural. Lots of roses with a good amount of oriental dna do just that.

There really isnt a cut and dried answer, Tangles.

I had a big long answer that devolved into a rant about disease resistance and lack of it it certain types of roses, The main gist of it was-

Yes , Spraying can work, but as some climates are just better suited to growing certain classes of roses, you either find what varieties are best suited to your particular climate, live with constant BS and mildew, or fight the natural conditions and as Gardengirl detailed, be prepared to put in what may be a lot of work with regular and systematic spraying right from the start of the growing season.

If your disease pressures are high, that can involve a lot of sustained effort.

I've only been growing roses seriously for about three years, but already I know I can't commit to spraying on a regular basis- its expensive, don't like wearing the gear, and as I also grow vegies and herbs around the garden the idea of spraying stuff near what I'm planning to eat is more than a bit of a worry.

You say you like older varieties, but apart from SDLM, you only mention David Austin roses; have you considered Tea Roses, or the Romanticas, Tantau or Delbard roses? Even Kordes are doing old fashioned looking roses if that is the style you like.

NB I grow PAOK too- blackspot is better than some Austins I have, but mildew this year has been awful...

Tangles, I'm in the no spray/ non toxic garden camp. There are so many OGRs and others that I leave to gardeners in climates that suit the cultivars/classes. Chinas, Bourbons and Teas are usually healthier, happier Roses outside the PNW (although a few other PNW forum members are much more successful with them than I am). I grow only the ones that trial and word of mouth have proven and then sit back and enjoy other forum members' photos of the ones I adore but can't grow without toxins and hair pulling.

If I could grow scrumptious vintage pink Hybrid Teas and Tea roses or Souvenir de Malmaison as no spray plants and match Ingrid's or Catspa's success, I would do so in a heartbeat! If my Chinas and found Teas looked like Jeri's, I'd grow them all! But alas....

Like Bart, I suggest growing roses that are good in your climate, I suggest giving troublesome roses the best culture and I suggest waiting a few years to give your roses the time they need to perform. With careful selection, I grow all my roses without chemical controls in the disease prone PNW. Good luck with your garden adventures! I completely empathize with the fungal frustration.

Carol

Tangles, I should add that since there are so many romantic OGRs and "new OGRs" out there, I've managed to find ones that satisfy both my desire for historical beauty and my climate. I am confident that there must be a list of OGRs, Austins and others that will grow wonderfully (healthily and vigorously without chemicals) for you and simultaneously meet your aesthetic needs. Carol

I have had good results using Hydrogen Peroxide (H2O2). Its organic, non-toxic and leave no residue. I buy a 4-6 bottles right off the shelf at Wal-Mart in the spring, they are usually in brown plastic bottles in the pharmacy area. I mix 2 cups in a gal. of water (H2O) and spray the leaves, canes and the soil area around each rose. Be sure to spray underneath the leave too. It is not residual, it works just like when you pour it on a cut on your finger, so you would have to spray more often or at least at the first sign of disease. It completely wiped out the mildew on my tall garden Phlox after spraying it twice in 3 days. It keeps blackspot, mildew and rust at bay with my roses but it is not the "holy grail" ..... it works best to spray in anticipation before the disease gets a lock on your plant. I have used it on tomatoes and cucumbers too. Do Not Use full strength - it will burn at that concentration.

That's cool, Gardenshine! Carol