I don't know. Mine is blooming now so I will watch it to see if that happens with it. It is in a place that I don't see it very often so probably why I never noticed it doing this before. It sure does take over tho. Guess I gotta start cutting it back.
My lamium (I have a lot of this stuff in different places all over the yard, in big broad clumps) blooms in spring and immediately turns ugly brown all over the leaves. There is even black. I cut it back every season with hedge shears, and over the middle of the summer it recovers and looks better. This happens every year. I think the browning is from too much water in the spring.
RIght now, in September, it's blooming again (WOW! It did this last year, too) and it's created a beautiful carpet of color everywhere, sun or shade. We've had almost no rain for months, and I have been negligent and haven't watered. So I'm concluding that the drought has been beneficial. I'm thinking the spring browning is from too much water and some type of rot or something resulting. If anyone really knows, I'd appreciate hearing. This is all supposition on my part. It sure looks nice now.
That's interesting. I never thought about it, but I have a creeping phlox I put in a little piece several years ago and it is probably about 8 ft x maybe 12 or more feet. Then I have a Thyme I did the same thing. Just a little piece a few years back and they have spread too. Not quite as big as the phlox, but they are in my perennial bed, and sure make a nice ground cover and beautiful when they bloom. I did have some Sweet Woodruff too, but it went crazy and I tried to get it all out, but didn't quite make it. It has tamed down some tho. It would crawl up the roses. ugh. I might put some of the Lamium over in that bed too. Have to think about that. They grow right around the other plants, roses, peonies, rhododendrons, etc. Wonder if the Lamium will do that. And keep the weeds down.
I had quite a lot of medical problems this year and haven't been able to do anything since early May. So, you can imagine the weeds. But none in these places.
Ground cover plants or creeping plants are great at suppressing weeds as you have found, I have to admit, you have to be selective where you want them to grow as things like Peonies, Roses and some other Perennial plants need plenty water to grow well and they don't really like Permanent ground covering plants growing up or around the root area due to the competing water demands.
While most annual plants will not be as demanding of water, perennials will at the hottest time of year and that's mostly when Roses, & Peonies ect are growing /flowering, so they might not like the shallower rooted creepers taking the moisture first before it reaches further down the soil for the Roses.
Just keep a close eye out for signs of drought around the larger plants. I had to remove a lot of the ground covering plants after flowering, lovely as the effect was, it made for poor flowering in my garden, they were moved to another area and I just thin them out every 3 years.
Hope this helps a little. Good luck and best regards.
I don't know about your brown spots, but one thing I can tell you about Lamium is you can cut it way back during the summer if it begins to get too long or starts to look ratty. It will quickly fill out again and even rebloom here and there.
I usually do it once or twice during the season. Mine is still blooming some right now in my Zone 5 garden (though not heavily). I have 'Purple Dragon'.