Black spot cure for the roses...

GrowsLotsaPeppers

Chillin' In The Garden
Joined
Oct 21, 2008
Messages
55
Reaction score
0
Points
29
Location
San Francisco East Bay
Hello! I'm new to the flowers & roses part here, but somewhat more familiar on the vegetable garden side.

Here's our problem, and maybe you have a suggestion:

There's a bad black spot problem this year on our roses. At least on 50 or 60 of the plants. Usually, I'd use something nasty toxic like a $35 bottle of Bayer from the nursery, but the budget is pretty tight this spring. Is there something else that you'd recommend?

I'm trying to keep things cleaned up, thinned out, pruned back, and the clippings sent off to the municipal greens collection. Any other ideas?

Thanks!
 

Northernrose

Attractive To Bees
Joined
Dec 31, 2009
Messages
124
Reaction score
16
Points
64
Location
Northern California
I have a book called Great Garden Formulas. It's a mix-it-yourself guide to formulas for plant diseases, pests and fertilizers. Here's two simple formulas for sprays. It also helps to remove as many infected leaves from the rose as you can and use a deep layer of fresh mulch around the base.

Baking Soda Blitz: fungal diseases like black spot and powdery mildew.

1 tablespoon baking soda (potassium bicarbonate works better and it's found in garden centers)
1 tablespoon horticutural oil
1 gallon of water
1 gallon pump sprayer

Mix and spray each plant completely including under the under-sides of leaves.


Deluxe Baking soda spray: Insects and fungal diseases.

1-1/2 tablespoons of baking soda
1 tablespoon insecticidal soap ( I think dish soap or Murphy's oil soap could be a substitute)
1 tablespoop canola oil
1 tablespoon vinegar
1 cup plus 1 gallon of water
sprayer

Mix and add vinegar LAST or mixture may bubble over
Spray entire plant!
 

Hattie the Hen

Deeply Rooted
Joined
Dec 9, 2008
Messages
1,616
Reaction score
7
Points
124
Location
UK.-- Near Oxford
GrowsLotsaPeppers said:
Hello! I'm new to the flowers & roses part here, but somewhat more familiar on the vegetable garden side.

Here's our problem, and maybe you have a suggestion:

There's a bad black spot problem this year on our roses. At least on 50 or 60 of the plants. Usually, I'd use something nasty toxic like a $35 bottle of Bayer from the nursery, but the budget is pretty tight this spring. Is there something else that you'd recommend?

I'm trying to keep things cleaned up, thinned out, pruned back, and the clippings sent off to the municipal greens collection. Any other ideas?

Thanks!
:frow :frow


Hi GrowsLotsaPeppers,

I'm sorry about your black spot problem but as a collector of old roses I beg you not to send your clippings off to the municipal greens collection as they will be made into compost & there is a good chance of the problem being passed on to other gardeners. That is why we are supposed to clear the ground around the bushes of fallen leaves & to burn all that waste.

Sorry to be alarmist & fierce but it helps to spread the disease . :tools


:rose Hattie :rose
 

vfem

Garden Addicted
Joined
Aug 10, 2008
Messages
7,516
Reaction score
43
Points
242
Location
Fuquay, NC
GrowsLotsaPeppers said:
Hello! I'm new to the flowers & roses part here, but somewhat more familiar on the vegetable garden side.

Here's our problem, and maybe you have a suggestion:

There's a bad black spot problem this year on our roses. At least on 50 or 60 of the plants. Usually, I'd use something nasty toxic like a $35 bottle of Bayer from the nursery, but the budget is pretty tight this spring. Is there something else that you'd recommend?

I'm trying to keep things cleaned up, thinned out, pruned back, and the clippings sent off to the municipal greens collection. Any other ideas?

Thanks!
I suggest sending the cuttings off with the regular trash, maybe even burning them. Like Hattie said, they will compost them and that will spread the disease on to your neighbors and even maybe back to you.

I use organic neem oil on my rose and my grape vines to help prevent black spot.... my neighbor is treating his that have black spot with my neem oil mix. So far he's been having great results!
 

GrowsLotsaPeppers

Chillin' In The Garden
Joined
Oct 21, 2008
Messages
55
Reaction score
0
Points
29
Location
San Francisco East Bay
OK. No more greens bin collection for the dead rose clippings with black spot. Can't burn them here, for air pollution and fire control reasons. We're in a serious fire control state...

The baking soda things seem the best cheap solution.

I'll have to google neem. I haven't heard enough about it to have an informed opinion.:/

Thanks, all!
 

Latest posts

Top