Hideous blackspot on all my roses, can I cut them back?...
 

Hi
We moved to a house with a lovely rose garden, however, that lovely rose garden is seriously ill! All the roses (David Austins) are covered in black spot. I began to remove the offending leaves before spraying but it is too prolific!
I am completely new to gardening and caring for roses and I as such, I have two questions that I hope someone can help me with...

I was wondering if I could just cut all the rose bushes right back (the steams look ill too).

Can black spot spread to other plants, as my clematis and some weeds, are now covered in spots that look very similar!

Thanks guys.
Krissy

Hideous blackspot on all my roses, can I cut them back?...
 

On Thursday, August 9, 2012 11:55:29 AM UTC-4, Krissy wrote:
Hi

We moved to a house with a lovely rose garden, however, that lovely rose

garden is seriously ill! All the roses (David Austins) are covered in

black spot. I began to remove the offending leaves before spraying but

it is too prolific!

I am completely new to gardening and caring for roses and I as such, I

have two questions that I hope someone can help me with...



I was wondering if I could just cut all the rose bushes right back (the

steams look ill too).



Can black spot spread to other plants, as my clematis and some weeds,

are now covered in spots that look very similar!



Thanks guys.

Krissy









--

Krissy

How hot is it where your are and or when will it be cooling off? You don't want to cut them back if it is hot, take off as many leaves as you can and wait for cooler weather. Black spot does spread.
MJ

How hot is it where your are and or when will it be cooling off? You don't want to cut them back if it is hot, take off as many leaves as you can and wait for cooler weather. Black spot does spread.
MJ[/quote]

Thanks for replying...
I'm in Gloucestershire and it has been very wet, although glorious the last few days!
I have noticed, now that I'm aware of the disease, that our pear and apple trees are riddled with it and they are impossible for me to attack! In fact, it is bloomin' everywhere!
Shall I just live with it until Autumn, then get rid of all leaves and prune the roses?
Thanks
Krissy

Hideous blackspot on all my roses, can I cut them back?...
 

On Friday, August 10, 2012 12:42:00 PM UTC-4, Krissy wrote:
How hot is it where your are and or when will it be cooling off? You

don't want to cut them back if it is hot, take off as many leaves as you

can and wait for cooler weather. Black spot does spread.

MJ



Thanks for replying...

I'm in Gloucestershire and it has been very wet, although glorious the

last few days!

I have noticed, now that I'm aware of the disease, that our pear and apple

trees are riddled with it and they are impossible for me to attack! In

fact, it is bloomin' everywhere!

Shall I just live with it until Autumn, then get rid of all leaves and

prune the roses?

Thanks

Krissy









--

Krissy

Yes, that is what I would do. Are you spraying?
MJ

Blackspot, "Diplocarpon rosae", is a nasty fungus that manifests itself on rose bushes as black spots on leaves progressing to black spots fringed with yellow rings on both sides of the leaves. As they develop the spots enlarge. Eventually, as the disease spreads, the entire leaves will go from green to yellow and then drop to the ground. With time the entire rose bush may become defoliated. Leaves less than two weeks old are the most susceptible to this disease.

Once you have discovered that your rose bushes are infected it is best to prune off the damaged parts of the plant and gather the diseased foliage. Dispose of this diseased material in bags or burn it. Do not add to the composter, as the fungus shall only return to haunt you when you recycle the soil back into the garden. It is vital to do an end of season cleanup so the spores will have no where to hide over winter.

After having removed the diseased parts from your rose bushes it is necessary to apply a preventative formula to minimize further attack. Using fungicidal soap or sulphur several times over the course of summer is one solution (especially after rain as these products tend to wash off). There are a few home remedies that have met with some success and are worth trying, especially for those that really do prefer organic garden methods. One is a solution made with baking soda: dissolve 1 teaspoon baking soda in a quart of water, add a few drops of liquid soap to the mix to help it cling better to the foliage, spray infected plants thoroughly. Another unusual remedy for fighting fungal diseases is manure tea. This formulation fights blackspot, as well as mildew and rust, while providing foliar nutrition. Place one gallon of well-composted manure in a 5-gallon bucket and fill with water. Stir the mixture well and let sit in a warm place for three days. Strain the mixture through a cheesecloth or mesh and use the resulting tea to spray disease affected plants (the solids left behind can be applied around the base of the plants as added fertilizer).