Is Rosa arvensis susceptible to fungal diseases?

I have a Rosa arvensis, wild English field rose, that I grew from seed, which has lovely flowers and hips but this summer, its second year of flowering, it was covered in mildew, rust and blackspot, in that order of problem.

Is Rosa arvensis especially susceptible to fungal diseases? Or is it due to growing in unsuitable conditions, and would more organic fertiliser help the problem? Our soil and water are chalky, and this plant and others grown in this spot have a tendency to form some white leaves, interveinal chlorosis. We have had so much rain this autumn that I think any tapwater I have used would have drained away, or maybe dissolved calcium and magnesium doesn't drain away? We recently got a water butt which supplied about half of the water needed in summer. I recently picked up a recycled bag of used coffee grounds given away free by a coffee shop and mixed this into its soil, to provide organic nitrogen and acidify the soil.

I do like this rose but mildew especially drives me crazy. What should I do to try to save it? Is Rosa arvensis particularly susceptible to fungal diseases especially mildew?

 

@groundbeetle are you growing it in the ground or in a pot? Also where abouts are you in the UK.
It would be better in the ground than in a pot.
Roses don't need acidic soil.
Any form of stress, more likely in a pot, will increase the liklihood of disease especially mildew.
The RHS say about Rosa arvensis and disease:
May be susceptible to rose black spot, rose rust, replant disease, rose dieback, and rose powdery mildew and sometimes honey fungus. May also be susceptible to disorders rose blindness and flower balling.

 

This rose is in the ground, which is chalky. Especially in that spot, but also in some pots, I have noticed leaves turning white, and we only got the water butt this summer so that could be the alkaline tap water. I read that roses prefer slightly acidic soil, can tolerate a range of pH, but don't like the extremes. I have added a lot of organic compost, and I have even used chelated iron, which doesn't seem to help. Some plants are fine and plants next to them get white leaves.

I don't know, but maybe the RHS just writes that about all roses generically. All roses may be susceptible to those things, but some especially very modern roses have amazing resistance to them. Some of my roses are completely clean of fungal diseases, and those also have lush deep green leaves with no chlorosis. It seems strange for a wild native English rose to be especially susceptible when modern hybrids are not.

 

Modern hybrids are selected for disease resistance, Rosa arvensis basically lives with all the fungal diseases.
Chelated iron will work for some forms of chlorosis, but not make a difference to fungal problems.
I don't know what the RHS says about other roses as I haven't checked them all.
I have never needed to water a rose after giving it good water when planted, even 1976 in the East of England we didn't need to water the roses.
As said earlier stress will make a rose more liable to fungal disease, stress can be caused by hot weather, dry weather or wet weather.

 

I just checked the RHS website for a rose that I know has superb resistance against fungal diseases, and has none of those problems, and it says exactly what you quoted for Rosa arvensis. So it is very likely those two sentences are used by them on the pages for all roses. So it doesn't help me understand the particular issues of Rosa arvensis.

It could be something as simple as not feeding the rose enough. Roses like plenty of fertiliser (except in winter).

 

To a large extent it will depend on the weather over the past couple of years, you haven't mentioned whether you had drought, a lot of rain, a wet winter, a cold spring/summer.
I've had all of these and I can see that some of the roses are struggling in my garden; not the two species roses though. Black spot, mildew and flower balling have all been present and relate to the poor weather.