Tar-like markings on stems

Ottawa, ON(Zone 4a)

Got some sick plants here. So far has infected mainly impatiens, both walleriana and balsamina but I fear it may be spreading to my oleander.

Black marks on the leaves (which subsequently wither and fall off) are followed by tarry marks on the stems. The plant doesn't die outright but becomes an "invalid".

Any clues? Can't find it in my books.

Deep South Coastal, TX(Zone 10a)

Sounds like some kind of bacterial blight. Pull out the infected plants and throw them away.
Cala

Ottawa, ON(Zone 4a)

The impatiens, both varieties have been pulled. The oleander is in a pot, so I've pruned it back hard and will quarantine it inside and see what happens. Have been spraying with a baking soda solution in case it's a fungal infection.

Deep South Coastal, TX(Zone 10a)

JanetR
Try one drop of tea-tree oil in 4 oz of water and spray it with this.
Cala

Lyndeborough, NH

Ortho Daconil has some effect on late blight aka phytophthora.

Ottawa, ON(Zone 4a)

Thanks for the input. Will this disease over-winter in the soil? I was thinking of avoiding impatiens altogether next year to avoid recurrence.

Deep South Coastal, TX(Zone 10a)

Janet
I would plant something else in there next year, just in case.
Cala

New Paris, OH

Do not compost your infected plants and don't landfill them either




BURN THEM


This is the best insurance that you will not spread the disease. Do not plant the same plant (or relatives of it) in the same area for the next few years either to allow the disease to die out. And finally get a postive ID on what ever it is killing your flowers. Take samples to your Master Gardener volunteer or your County Extension Agent. Once you know what it is than you can deal with it.

Ottawa, ON(Zone 4a)

Ohio, I'm not American and I don't know what you mean by a County Extension Agent. Extension of what? Department of Agriculture? How would I go about finding a Master Gardener?

I'll keep all varieties of impatiens out of the back yard for a good while and avoid the nursery where I bought the plants that I believe to be the source.

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