Fungus on Guelder Rose- how to salvage?

[GneissPlace]

I was told this Guelder Rose shrub has Septoria spot on its leaves. My question is, should I prune out the affected leaves immediately or wait till winter? I am in Virginia. I am uncertain how to prune it all out as well because its covering the majority of the whole shrub! I just moved onto this property and would like to salvage it. It is in full sun and from my knowledge it has not been given any care for the last several years.

 

[YumYum]

You could try using 1 pint of 3% hydrogen peroxide per gallon of water and spray the leaves. I haven't tried it on septoria leaf spot but have other things. If that strength does kill the fungus the leaves will still look like crap but the disease shouldn't spread so that may salvage the plant for the rest of the year. Next year or cycle the disease will probably be back so I'd be looking for it at some point.

Be sure to clean up all the litter around the shrub. I would also wait until the plant is in shade to give the peroxide more time to work without evaporating.

 

[GneissPlace]

Thank you! I hope it can be a little more healthy next year.