Climate area?

My rosemary plant looks like that, too, and it has been struggling since it rained for a week back in June. It's some kind of blight, downy mildew or something else. I'm taking my plant out when I get around to it.

Could be several issues. 1. Wet feet. Rosemary is a Mediterranean native and wants mostly dry soil in the summer. 2. Planted too deep in the soil - dig it up and raise it about 1 inch above the soil level. 3. Might be getting old. Rosemary is not terribly long lived. I would cut off a bunch of branches about 6-8 inches long. Strip off the bottom 5 inches of leaves and put into a jar of water filled to 4 inches. Leave in sunny window - watch to make sure water level is steady and changed often, and when they get good strong roots - 4 - 6 weeks, replant in soil. Now you have lots of plants! lol

My rosemary plants were having issues the past two seasons here in Zone 7/NJ). They were getting very yellow foliage and previously, they were FINE and developing into hedges. Then, I noticed that I had an absolute infestation of thrips on all my rosemary plants. I attribute it to the tendency recently to have very stagnant, HUMID, sultry. fairly overcast summers that set them into decline (or maybe the bugs came first). I ended up ripping out the older plants and replacing them. We'll see, this is yet another monotonous HUMID, stagnant summer with lots of rain and without any decent DRYING. Recent summers have not been kind to the Mediterranean herbs being grown here in the East (Ga, Va, NJ, etc.) One thing to help the situation is not to crowd your plants in the garden, give them space and allow for ventilation. See any evidence of insects activity? i didn't notice the thrips until I shock the leaves and they started fluttering about.

Try weeding around it, looks like the roots of the weeds are choking out the roots of the plant. The root on the weeds, will also hold water in, next to the roots of the Rosemary, and you already know Rosemary doesn't like being waterlogged. Then you can dust it with some sulfur, like Lilly Miller, after trimming out the pieces that look like they have mold spores, if there are any. Lilly Miller sulfur will prevent Downy mildew. (Google: downy mildew on Rosemary. And then compare the two. - you can also Google: common problems with Rosemary in GA) - I live in South Carolina right past the Georgia Line in Augusta, and we have had many issues growing Rosemary here. The weather is so unpredictable and sometimes we get rain for weeks, and then we don't get rain for weeks after that.. this summer I have been adding diatomaceous earth to the soil for my basil and lavender and rosemary. It seems to help dry it out a little when we have too much rain. I may have to water it a little more but, that's perfectly fine with me as long as there is no mildew and mold! (Good Earth- from Amazon, about 15$ for 10 lbs! It last forever if you don't just sprinkle it around wastefully. Pour it into a sock -using a funnel- then tap the sock over and around your plant. Or, if you have trouble getting it on the underneath of the leaves, look online for the recipe to add it to water, then spray it onto the leaves of your Rosemary. You will have to reapply every few times and it rains)

The OP has never returned with further information. Rosemary grows very well in the British Isles so rain per se is not a problem for it. The discoloured foliage looks more like a pest issue to me. But without more pictures and information we'll never know.

Floral, am I OP? ophonex? If so, the rain by itself is not a problem for Mediterraneans. It is also the humidity, type of soil and the difference between the daytime and night time temperatures, also called the diurnal.

Definition of diurnal

1 a
: recurring every day

• diurnal tasks

b
: having a daily cycle

• diurnal tides

It was a new word for me and is one more instance where the Hardy Growing Zones do not tell the whole story.

Here are links to two interactive maps by Grolier online atlas.

Climate Zones Europe

North America, Climatic Zones

OP = Original Poster (or original post :-))

Mediterranean climates tend to have low summer humidity. And the rain is also very seasonal with little to none in summer but adequate in winter. Growing rosemary or other distinctly Mediterranean plants in climates with highly humid summers and copious summer rainfall can give rise to all sorts of disease issues as well as the potential for root rots.