soilistheanswer
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Joined: Mon Jun 10, 2013 7:45 am
Location: Densole Kent uk

Black spot

I have decided to grow roses this year reason being to cutdown on maintenance any good tips.
The roses that I now have are prone to black spot.
John Ralph :)

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applestar
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Location: Zone 6, NJ (3/M)4/E ~ 10/M

Re: Black spot

How badly susceptible are they? Any plans to replace them with resistant cultivars?
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imafan26
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Location: hawaii, zone 12a 587 ft elev.

Re: Black spot

Get roses with glossy leaves, they do better with blackspot. If it rains a lot there isn't much you can do without a regular fungicide program. If you know rain is coming you can start a preventive program using either sulfur or an oil but you have to choose one since they cannot be used within a month of each other. Space the roses so they have very good air circulation and prune them into a vase shape. They should be pruned and fed after each bloom cycle. If you do have blackspot you will need to pick up all of the damaged leaves and destroy them to keep the spores down.
Happy gardening in Hawaii. Gardens are where people grow.

soilistheanswer
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Posts: 9
Joined: Mon Jun 10, 2013 7:45 am
Location: Densole Kent uk

Re: Black spot

Thank you for your interest. I have treated myself to nine new roses and they were planted early March and now doing well I have looked back on this forum and noticed that one post surgested using milk and water that I have been trying on old roses some of them had been planted before I moved into the house. I been given to understand that this virus stays in the soil and when it rains it splashes the leaves.
John Ralph :)

imafan26
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Posts: 11677
Joined: Tue Jan 01, 2013 8:32 am
Location: hawaii, zone 12a 587 ft elev.

Re: Black spot

Black spot is not a virus, it is a fungal disease and it spreads by spores. That is why good sanitation is important and keeping the leaves as dry as you can.
Happy gardening in Hawaii. Gardens are where people grow.

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rainbowgardener
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Location: TN/GA 7b

Re: Black spot

But the diluted milk is a treatment for plant fungal diseases. Other treatments include hydrogen peroxide and baking soda solution.
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