Rosemary disease?

EvilMonkey · Posted: Tue May 10, 2011 11:39 am Post subject: Rosemary disease?

Anyone know what's wrong with these Rosemary plants? The leaves are turning redish brown and eventually drop off or die

The first two is a new plant i got recently the third is a cutting(the only one that survived the winter!) from an established plant that died last year with smiler problems.
Anything i can do to treat this? Should i pick off the damaged leaves?

Sive · Posted: Tue May 10, 2011 3:23 pm Post subject:

Horrors ! I have a 20ft run of rosemary bushes that I hope to establish as a low hedge, and I have had some casualties....I just presumed the damage was weather-related. I don't think I could cope with yet another disease.......not when I am already facing pulling up a large amount of escallonia plants in another hedge.
Has anyone out there heard of a rosemary disease ????

Garlicbreath · Posted: Tue May 10, 2011 10:42 pm Post subject:

I've lost 2 of 3 rosemary bushes in the last 2 years. They just turned brown and died. The last one is looking healthy now though. Fingers crossed :-

I think I posted here before about it but ... it's late Smile

EvilMonkey · Posted: Wed May 11, 2011 6:09 pm Post subject:

I always thought Rosemary was fool prof. I read online it might be from over watering.
Does the damage in the pics look like its from too much water?
I might try moving them to a sheltered spot and not water them for a while, even though it has been relatively dry recently with only a couple of showers.

michael brenock · Posted: Wed May 11, 2011 10:08 pm Post subject:

in exposed situations it is subject to wind blow. This can be even worse where ground gets wet over Winter due to poor drainage. Plant replacements in a sheltered situation and check that drainage is satisfactory.
michael brenock horticultural advisor (retired)

Sive · Posted: Thu May 12, 2011 6:57 am Post subject:

Not what I wanted to hear, Michael ! My short rosemary hedge is in a very windy spot. Is there any small shrub that would do better there ? Something that wouldn't be taller than about 3 or 4 feet ?

michael brenock · Posted: Thu May 12, 2011 10:35 am Post subject:

Spirea Japonica Anthony Waterer, Hypericum moserianum tricolor, Philadelphus coronaria aurea, Potentillla varieties, Mahonia aquifolium, Ligustrum ovalifolium. These are a few that might fit the bill.
michael brenock horticultural advisor (retired)

Sive · Posted: Thu May 12, 2011 1:57 pm Post subject:

Thank you for your suggestions, Michael, I suspect I'll be putting in a little potentilla hedge and moving the surviving rosemary bushes.....if they transplant at all, that is.

gardenman · Rank attained: Hazel Tree Joined: 04 Aug 2011 Posts: 33

Looking at the pictures and the liverwort infestation on top of the pot, I think they could be hungry and suffering from Phosphorous deficiency which would cause purpling on the lower leaves first.
The fertilizer in pots will only last for 12 months and may have been close to expired when you bought them.
The cold winter may have added to the problem causing some root death of the plant which would have reduced the plant scapacity to absorb any P.