Houzz Logo Print
mindstorm_gw

Efficacy of Copper fungicides

12 years ago

Hello,

It seems that I lurk here all year and right around this time of year, post here in a panic trying to keep my hair on straight.

Background:

I am in zone 6a-5b; have 4 roses : 2 Abe Darby's, 1 Wise Portia and 1 Glamis Castle. Have had two other roses that sadly never made it. My roses get about 6-8 hours of sun but sadly, only starting about 10:30 or 11:00am. They are planted in the front of my Southerly facing house, so they are shaded by the house in the early morning and get sun only after it comes around. Little I could do about that when I planted because that was the side of the house that got closest to the recommended minimum 6 hours of sun. They seem to have taken to the locale; the Abe Darby's are closing in on 8 feet tall, throwing new canes and new growth galore, have heaps of roses and loads of leaves every year; WP and GC are small bushes but have loads of flowers, leaves and grow new canes regularly (this is GC's second year in the ground with me).

My problem:

Partly because of the location, i think, the roses tend to get blackspot and get it early. I have tried to stick to a regimen of organic or light treatment and have only given them the Bon-Neem treatment - but am not sure how good that is for BS prevention. I have cleared winter's mulch, given them new compost, organic fertiliser (rose-tone), new peat-moss-ish mulch but I am seeing some early onset BS already.

Yesterday, I decided to see if I could get some respite with something a bit different and applied the copper fungicide. So copper-salt powder mixed in water and sprayed on the plants. Well, once the water dried, I am left with these yellow-blue splotches on the roses.

My questions:

Basically, are these my options? Either black spots or yellow-blue ones?

Thanks in advance to recommendations to shovel prune and get different plants but I'm looking to see what I can do to protect the plants I do have in as sustainable a way I can do so. What are my options for a relatively non-toxic, non-poisonous way of life that can benefit my roses by developing their natural resistance; or at least not slaying the little bit of eco-sphere around here?

Oh secondly, if I do have to live with the yellow spots, do the copper fungicides work; are they harmful to the plant or will i have devastated my beautiful roses?

Thank you in advance for any suggestions. I have read and read about BS and while I read that the Bayer Advanced Disease Control is recommended, I also read about the organic options and can't help but want to try the organic solutions before committing to the chemical. I'd love to know if I should be able to expect any real help from the organics or if they are just a pipe dream.

Roses are a fetish that I never thought I'd develop but develop I have. We've got rid of some trees towards the back (well, weeds more than trees really - Norway Maples which are rampant here and want to grow in every chink in the landscaping armour you might reveal, regardless how irresponsible the location) and am looking greedily to see how much I can stake out for more roses here and there (disease resistant ones this time).

Comments (9)