3

It seems that only two systemic fungicide are still on the UK market sold for rose black spots being Triticonazole (UK brand name: Fungus Clear Ultra - Scotts Company) and Tebuconazole (UK brand name: Bayer Garden Concentrated Fungus Fighter)

Can anyone point me in the direction of any research that shows how there effectiveness compares with each other?

(At present I try to use both in year and need to spray my rose hedge every few weeks to keep it clear of black spot.)

Improve this question

1 Answer 1

Reset to default
2

Neither product is massively effective, simply providing some control of the problem, and neither one is any better than the other, as far as I can tell in use. The one I usually recommend for roses is Roseclear Ultra, which is a combined preparation of an insecticide and a fungal treatment (triticonazole), so it deals with aphid infestation too. Can only be applied 4 times in a year, and should not be used while the bees are still working, if the flowers are open.

https://www.lovethegarden.com/products/pests-disease/roseclear-ultra

However, given you've got a hedge, where black spot is much more likely to occur anyway, and it's difficult to get a spray to reach all parts because of the 'thicket' like nature of the growth, then I'd suggest a natural, non harmful treatment for fungal infection, particularly black spot - cow's milk. Mix one part milk to two parts water in a sprayer, and spray till run off. And you can use that mix as often as you like or as necessary, without harming anything in the environment.... link below

http://www.agardenforthehouse.com/2012/05/got-black-spot-get-milk/

Improve this answer
5
  • I only use Roseclear when I have an aphid problem, as I don't wish to use more "chemicals" then I need on my 110 foot rose hedge.
    – Ian Ringrose
    Apr 25, 2016 at 13:00
  • Well, the milk solution is ideal then... with the occasional insecticide separately for insect pests, if you feel you must treat for those.
    – Bamboo
    Apr 25, 2016 at 13:00
  • 10% solution didn't work for my mildew problem. Maybe next year I'll try 30-100% as per the comments in your link.
    – Graham Chiu
    Apr 25, 2016 at 20:01
  • @GrahamChiu - supposed to be 1 to 9 for powdery mildew, and 1 to 2 for black spot - different conditions. And the milk treatment only works on powdery mildew - downy and other forms of mildew do not respond to this treatment.
    – Bamboo
    Apr 26, 2016 at 9:33
  • Bamboo told me about this ratio for milk and water and believe me it works for powdery mildew. Powdery mildew is the only fungus I know that can be controlled or 'cured' AFTER the fact the plant gets this fungus. One fungal spore can innoculate the entire plant and the best fungicide is sort of a 'raincoat'. Not allowing water to splash off the ground and onto the plant. Please send pictures of your black spot on your hedge. Sometimes it is beneficial just to relax about a few insects a few spots. Completely normal and healthy plants can usually take care of this stuff all by themselves.
    – stormy
    Apr 26, 2016 at 22:06

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.