Hi friends,

What is your advice to treat blackspot on Roses ?

Thank you !

I keep asking that same question. Each year I start out with great expectations, and each year my roses fall victim to black spot. I know you have to be persistent and follow a regime on schedule or it is a hopeless battle.

Thank you Larry,
I noticed that it started on few of my roses, I have the spray but wonder if anybody have better idea that do not involve chemical...
This is part of an article at Gardenguides.com, anyone tried these ?

"Alternative Fungicides
Alternative treatments to traditional chemical based fungicides to help stem the advancement of black spot include lime sulfur, neem oil, hydrogen dioxide, potassium bicarbonate and copper products. These can be applied as a liquid spray."

Thanks,

I hardly ever get blackspot, and I don't spray or use any of the alternatives listed. While I do live in a somewhat dry climate, I do deal with rain at night, which is not good for roses, especially here, where nights can stay warm.
I mostly buy resistant roses to begin with, and I space them at least 3 feet apart. I use either bark mulch or plants on the ground between the roses instead of bare dirt. If I irrigate, it's early in the day, and I use a drip hose. The roses are planted in full sun, in a windy area, which I think helps.
Climate has a lot to do with it, I know, but friends near me do fight blackspot, so I think the way I'm growing them is helping.

Cindi...

I have used Serenade for years with great success.
Bayer now owns the rights to Serenade and they also sell Sonata which is similar but a different strain of fungicide.
I use both as a professional site said the diseases are like those in humans and can adapt so by switch strains of fungicide they will not get used to the same old, same old .

They are totally non-toxic, you can drink it but that is not recommended.

I drench the plants and soil in spring and fall, I have to cover my roses, and have found burying works best so to kill the disease in the soil is very important.
If you watch the plants and pick off the infected leaves, that will do more to eliminate the problem than even the best fungicide.

If you buy new roses treat them before you put them in the garden, I have had more problems with them spreading it than anything else.
I grow mostly hybrid Tea roses.
I also found that by putting a layer two to three inches deep of Coco mulch in the garden help in two ways; even in a heavy rain there is no splaching up onto the leaves from the ground and Coco mulch , I looked this up, has fertilizer effect of 2.5-1-3.

I used to have over three dozen roses but due to my mom passing on, they were her roses, and other concerns, I stopped replacing ones that died, either from winter kill or because I was moronically careless.
I lost two old roses that were not recommended for my area I put in due to stupidity on my part after they were eight years old.
That kind of took the spark out of me after mom was gone and I no longer had the main reason I cared for them.
I am down to a little over a dozen now but next year I may add a dozen, although winter prepping and uncovering in spring two beds verses three, was a LOT less work.

I did lose a few due to other "experts" saying do this, or this, or this rather than simply following my gut instinct I gained from watching mom.

Serenade and Sonata also work VERY well on vegetable vines, tomatoes and anything that gets leaf problems.
One year I used it to stop corn rust.
I buy the two and one half gallon jugs as it is FAR, FAR cheaper.
Peaceful Valley is the only place I know selling Sonata but just put Serenade, or Sonata, -- 2.5 gallon jugs for sale -- in your search engine and you should find some sources although for what ever reasons it is not as easy to find as it used to be.

Rpr, wow, that is super helpful! There is a nursery in Canada that ships roses to the U.S. and they have many beautiful roses that would not need to be covered in your area. They are all disease resistant, and would not need spray at all. Palatine is a favorite of many of the people on the rose forum because the roses they send out are huge.
https://palatineroses.com/
This has been a bad year for blackspot in my garden. It is easy to tell which roses are truly resistant, after getting 10.5" rain in one week. The Palatine roses, mostly Kordes and Fryer, are 90% clean!

I make up my own spray - got it from an old organic rose growing book I found somewhere -- it changes the pH on the leaf to make it harder for black-spot to grow. 1/3 part milk, 2/3 parts water. A few drops of dish soap, A few drops of vegetable oil. A couple drops of vinegar (optional). The milk to water ratio does not need to be exact. Keep the remainder of the spray in your fridge - it's ok for the milk to turn sour - good even. Spray often, especially in humid weather and after a rain. Been using it for years, and it seems to work pretty well. If the weather gets too humid, then I do sometimes supplement with other commercial sprays.

CindiKS said:Rpr, wow, that is super helpful! There is a nursery in Canada that ships roses to the U.S. and they have many beautiful roses that would not need to be covered in your area. They are all disease resistant, and would not need spray at all. Palatine is a favorite of many of the people on the rose forum because the roses they send out are huge.
https://palatineroses.com/
This has been a bad year for blackspot in my garden. It is easy to tell which roses are truly resistant, after getting 10.5" rain in one week. The Palatine roses, mostly Kordes and Fryer, are 90% clean!

For five years or so I ordered from Hortico.
They honored they warranty but some of roses they sent were pathetic from the get go, although I nursed a couple to health but then some that looked real good were belly-up the next spring plus after my one large order it seemed two-thirds were on back order for year after year.
Where I am at, I have two gardens now fifty miles apart it can hit thirty below at the south garden and forty below up north so not covering is not an option.
When I just covered them I would have to cut them down to no more then twelve inches so they started from near scratch every year.

A gent down the block buried his every year (he came over one year to see how mom got away without burying hers).
After a couple of hard winters and losing some roses, I decided to try burying them, especially as I had done that for the land-scaper I worked for.
Since then loss rate has dropped to near zero, and now, although it takes a LOT of space, I tip up roses with canes over three feet long.
Now I found that in the spring after you remove the leaves over the buried roses, and sometimes I put a cloth covering on the ground also, it looks like a black mat, or a worm highway.
I thought well, I will just tie some bailing twine on the stems and I will know where they are.
Well, so far every year the bailing twine has disappeared under ground.
I have lost one rose because I forgot it was there and did not find it till the fall while digging a trench to bury another one and a few times a few week after uncovering I will see sprouts coming out of the ground where I missed one.
If you bury a rose and it does not sprout through the ground it probably is on its death bed.

One of the reasons I have not planted more is I realize that then I would lose the area to bury the long canes but I am still going to put more in next year.
For a long time up here we had a discount nursery where I could buy high quality roses at a fraction of the listed price, so losing a rose then was no great bother as I could simply get another nice one.
Sadly it closed a few years ago.

The year I got my biggest order I fall planted.
We had a hard, hard, hard freeze. Now obviously the garden was not covered, you are supposed to wait for a truly hard freeze if you just cover them, but I had over a dozen roses in boxes that needed planting.
I went out with an ice chisel broke the ground up, it was frozen solid an inch and one-half down, threw the chunks into the vegetable garden and roto-tilled the area to be used.
My rose garden has very hard black-gumbo, has always been that way and no matter what I do it does not change but it grows nice flowers.
Well the day I planted them there was a freezing drizzle all day but I had no choice so I just kep going. After you get cold and wet to a certain point you actually stop noticing it as no part of your body is any better that the rest.
Well I thanked God I got them all in and got the entire bed covered with leaves.

A week later it was in the seventies and I ended up mowing lawn again that fall.
They looked great the next summer.

Rains everyday, it's hard to get rid of blackspot, I guess I just have to wait till the Sunny days come back ...

My Hortico roses look awful. Of the four I ordered, the 2 Austins are slowly leafing out, after a whole month. One other one (Nahema) is green and black and might still leaf out. The one I most wanted is slowly turning brown all over. I guess I'm spoiled by the high quality, huge plants I got from Palatine. Hortico's plants look like they came out of a dumpster. They came with diseases I don't even recognize.
Our rain has finally stopped and the new growth on about everything appears to be spot free!

I just planted my Tuscan Sun bare root, a few days ago, got it from Jackson & Perkins, also have Summer Night, Sugar Plum in bare roots from them, like these better than their 2 quarts size...

RpR, do you dig the roses up or just pilling the soil on top of the rose?

Cinta said:RpR, do you dig the roses up or just pilling the soil on top of the rose?

I dig a trench next to the rose.
First I make sure the roots on the side of the rose to be tipped are in looser soil then I a shovel and pry up, just bit, trying repeatedly till the rose tips comparatively easily.
I bury most of the tipped branches with dirt; I have heavy dirt so often I just take the largest chunks and just make sure they hold the rose down.
By spring time the entire stem will be covered.
Then I put a mound of dirt over the raised part of the root ball.

In my soil by spring when I uncover them all you will see is flat black dirt, with a few dips and mounds.
I also put leaves over the roses.
Picking up the leaves in spring is easier if you put fabric over the rose bed and the leaves over that. Then in spring after removing x amount of leaves with a fork, you can grab the corners of the fabric and make a bundle to pull off of the rose bed.
I found a car cover to work best.

Without the fabric, depending on how cold it gets where you are, you should add at least an extra six inches of leaf cover.
Depending on leaves used, in spring, two to three feet of leaves will often compressed down to eight to sixteen inches.

Unless you have a very good memory, use something to at least mark where the end of the tipped rose bush is located.
For some roses I will dig one trench and tip them towards each other.
As I said I have hard soil and it somehow fills in the hole even if I leave the hole half empty.
When I uncover them, even when I marked where the ends were, they just seem to be a lot deeper than I remember planting but then when I am done burying in the fall the bed is full of pits and bumps but by spring it is darn near level.
When I uncover them in spring using fabric, I will find many worm trails with large night-crawlers some times in transit.
It looks like a a 3d highway map.

When you dig them up in spring, be gentle if you have long canes.
Some times I will snap them off because I tipped them up too quickly.
Also dig a hole and loosen the part of the root ball, so that dirt is not stopping it from going back into place, that is being tipped back into place.

Thank you RPr. I am going to give that a try.

Hi rose growers I am new! I like how friendly and easy going you all seem to be. I look forward to chatting with you.

Hi, Sly1. Welcome to NGA. We look forward to chatting with you too!

Sly !