"Systemic granules worked into the soil" for blackspot control. Is there such a product?

There is no such product. There is a soil-drench product that doesn't work very well. I spray with Bayer Rose, Flower, Shrub Disease Control every two weeks.

My bad!! I'd been told that there was such a systemic for BS. Thanks for setting me straight. Pembroke

The systemic granules are insecticide or insecticide/fertilizer combo. This insecticide (Di-syston) is extremely toxic and dangerous.

Michaelg---"Never say Never..." I have used Bayer All in One Granular worked into the soil for systemic control of fungus. Somehow it popped up here in MI.-hadn't seen it before. I couldn't find my usual product. American Rose Society endorses this item and others-I know some folks have reasons to boycott various products or chemicals but there is a market for them. I still have worms, birds,butterflies,toads in my garden--I use only on my roses so far with success. Mike Rivers will have to acquaint himself with the various products available, and yep there is a granular version.

Pembroke-I must clarify. There is a granular product which is intended for insect and fert. This product does not offer fungus,black spot control-Michaelg is correct that this product is not desirable. The drench product is the one I use and it does help control fungus, blackspot.
Please read the labels and memorize which one you are using.There are a lot of similar products! Don't get the products mixed up. As you see I am a good example of not remembering my labels correctly. Goodluck with that blackspot!

Since BS is a soil borne disease that is initially on the leaf surface, spray is the only way to go. Systemics work inside not the other way around.

Soooo If the BS disease is soil born , why shouldn't we be attacking it in the soil where the feeder roots are. Does the BS disease travel up the stems and then to leaves where we then can see the spots? just trying to learn more about BS. Pembroke

The BS disease is a fungus. Fungi reproduce via spores. The spores land on uninfected foliage and canes, and infect them. The fungi grows and produces spores, and the cycle continues.

The spores may be on the soil and kicked up onto the foliage by rain or wind, or it may by spread by breezes or winds.

Systemic controls enter the plants through the roots. The chemical travels throughout the plant, leaves, canes, etc. and theoretically protect the leaves and canes from infection by spores.

Hope that helps.

Once BS get on the plant it stays there forever. Lesions on the green bark carry over to spring and release spores which are carried by splashing water to the leaves. Then spots on the leaves release more spores which are carried by splashing water to other, nearby leaves. The gardener's hands and gloves probably play a big role in spreading the various strains around the garden. Spores are relatively sticky and heavy, so it is not as mobile as other fungus diseases.

It is not primarily a soil-borne disease, but infected fallen leaves on the mulch can be a source of reinfection.

Soo If I prune real heavy in the Spring, the BS is still there? No way to STOP BS? what about the sprays that are on the market? Learning as I go. Thanks. Pembroke

Hard pruning in spring can delay the onset of disease by some weeks. It also delays and reduces the first flush of bloom somewhat. In zone 6 you prune hybrid teas (etc) according to winter damage-- often this means pruning to short stubs.

Spraying with Bayer Disease Control every 7-14 days can virtually eliminate symptoms, but I doubt it eradicates the disease from the garden permanently. Here we have some of the heaviest blackspot pressure anywhere, but with 14-day spraying I've lost very few leaves this season. 7-day spraying may be needed for the most susceptible varieties.

Blackspot is always around. You can grow varieties that are resistant to the disease. But, in areas of the US with high humidity, hybrid teas are not resistant (there are some that don't totally lose their leaves, but not many) and have to be on a regular treatment program. Leaves are fundamental to rose health.

Take michaelg's recommendation, use the Bayer Advanced Disease Control product regularly (starting a week after pruning in the spring and continuing through October), and you'll be able to keep blackspot at bay.

Michaelg-something has always been a problem for me to understand; We are told to rinse our rose plants with a nice spray of water to keep aphids and mites washed off the leaves. I do this as a regular practice in the early a.m. during summers. Am I doing more harm than good? When we do this are we really just helping the BS spores to spread?? Thank you any discussion.

Daisy,

Good question. I've wondered about this too. As you know, the spores will not germinate immediately if the plants dry within 6-8 hours.

Yes, it seems that a hard spray of water would spread some spores around, but there aren't many (or any) spores on the new growth where aphids live. If you commonly have mite problems, it is necessary to spray under the lower leaves where there may be spores to spread, but on balance you would be doing more good than harm. I rarely have mite problems (high humidity, no insecticide to encourage them). In such a case, it might make sense to avoid unnecessary spritzing.

Rinsing the top surface of leaves downward can wash off blackspot spores.

If we rinse the top surface of leaves downward and wash off BS spores is this going to infect the ground or mulch and then splash back onto the plant? Thanks for all the great info on this subject.Pembroke

Spores on the ground are less hazardous than spores on the leaves. Almost all BS lesions originate on the top leaf surface.

I don't want to exaggerate the benefit, but overhead watering (in the morning) has been shown to reduce BS somewhat. I was just thinking that if you are concerned about spattering spores with your mite treatment, you could finish off with a rinse that would remove some of the spores. Especially if you would be watering anyway.

These look like good formulas plus one for use in hose-end sprayer.

Sherry

Here is a link that might be useful: Good link for formulas.

Sherry, in my experience baking soda works for PM, but not for BS. Vinegar doesn't work for BS here, don't know about PM. Baking soda probably can work where the BS is not a big issue, but where it is really bad, these formulas are useless.
Olga