black spot on rose petals

commuterised

What is the disease that my roses have?

It's got black spots on the leaves.
How do I get rid of it and what time of year is best to do it?

thanks in advance...

Victor

Originally posted by commuterised
It's got black spots on the leaves.

I think it is literally called "Black Spot". I think it is common and there are sprays for it.

http://www.myhome.ie/improvements/gardening/rosegarden.asp

PhilipMarlowe

If you want to read lots more... http://www.herts.ac.uk/natsci/Env/Fungi/Blackspot/title.htm

Usually for a domestic garden, you would spray with Nimrod-T (a fungicide) or ‘Rose Clear’ (a combined Insecticide against greenfly, aphids etc. and Fungicide against rust, black spot etc.) about every 2 weeks in the summer, especially in warm, damp conditions (ie. Ireland :rolleyes: ).

If they are pretty bad, you could give them a winter wash with ‘tar oil’ while dormant (December) which may help them next year. Also, you would then begin to spray with the fungicide as a preventative as soon as leaves emerge and continue throughout the season.

Some varieties are more resistant than others…

Mark.

commuterised

excellent thanks people!