This is a Potentilla fruticosa Bush Cinquefoil Rosaceae
Photo from the UofCN Ext Hort page.
I had a question the other day about why the Potentella bush was turning brown and looked like it was dieing. Since the best answer is probably weather related, I thought I'd share this information with everyone.
Potentillas are "xeric" plants that need very little water to survive and thrive. With the massive amount of rainfall this year, it has almost been a death song for Potentillas. Henry County IL is currently 9.5 inches above average rainfall for the year.
If your bush is dead looking, scrape the bark tissue on a couple of stems. If the tissue beneath is green, the plant is still alive. If none of the stems have green tissue, you may as well dig it up and throw it away.
Potentillas are a long suffering plant that may take many years to die. They may loose their shape and have dead branches. They will suffer in silence when they are treated "too good."
Potentillas should be neglected in some ways: Don't water unless there is a severe drought with no rain over three months and never fertilize.
To give an old plant a chance at new life: Cut the bush back hard (back to ground level) in the fall (or before any leaves emerge in the spring.) If there is any life left in the bush, you will see a mass of fresh green growth next Spring. It may take a year or two to begin blooming again. If it does not come back, it means your bush was beyond help and it's time to dig up and plant another.
This bush has been used extensively by commercial landscapers around businesses because they require no watering and have a long bloom time. Then, they begin to look ragged and those awful plants you see are the result of no one continuing the heavy pruning plan. They are often planted among rock mulch which they can take but it also makes it difficult to keep groomed. Many are planted in mass but they aren't dense enough to keep all the weeds/grass out and again, they are expected to do something when they haven't the ability.
These are beautiful plants and add yellow buttercup looking flowers from June until frost. They survive in places where more water needy plants could not (rock gardens as an example.) They just may not be a forever bush during a series of heavy moisture years and they do need to have heavy trimming at times. These factors do not detract from the value of this beautiful little (1-4 ft) bush .
They have few pest problems. Plant in full sun. They adapt well to Bonsai use.