Identify any new plant that pops up in the garden

Sometimes I discover a new plant which I never planted and I let it grow, until I figure out whether it is a good plant or a weed. In most of the cases, the plant is a weed and it has to be eradicated from my garden. I always do thorough research before taking this ultimate measure on a plant. I'm always concerned that if I discover later that my plant was useful that I would regret my actions. Meaning, after I eradicated it, I learned it would have been welcome in my garden? Cinquefoil was one of those plants that had to go from my garden, although it was a good plant in some parts of the world and in history.

Never let a weed reproduce

I noticed the palmate leaves growing in my garden one summer and I remarked on their resemblance to the strawberry plants. Yet they weren't strawberries, so I had a new problem to resolve, whether it was a good or a bad plant. I decided to let it grow to wait and see. I had lots to do in the garden, as I always have in the spring, such as trimming back the trees and bushes, sowing the vegetables and the flower seeds, mowing and scarifying the lawn, not to mention weeding. My new plant was good at first, not so invasive with just a few plants here and there. But the following spring it started to grow and it spread rapidly, so in April it completely covered a small part of my garden where I usually had all colors of Sweet William (Dianthus barbatus). Instead of having dozens of colorful blooms, I just had lots of leaves from the bad weed, which invaded my garden and struck down its first victim. It was high time I researched about that weed (why didn't I do it the first time I saw it?) - because I was sure even then that it was a weed!

The history and uses of Cinquefoil

I discovered that it was a creeping weed named Cinquefoil, after the five-leaflets on each palmate leaf. The Romanian common name is Cinci degete meaning 'five fingers' in my language. Its Latin name is Potentilla reptans and it is classified in the Rosaceae family, genus Potentilla. The flowers are yellow, yet I didn't get to see it blooming. Some Cinquefoil species make some small, inedible brown-red strawberry-like fruits, which led to another common name, the 'barren strawberries'. The trailing stem roots at the nodes or joints in the stems, just the same as the strawberry plants. That makes it hard to eradicate, because the roots are deeper than the strawberries' and it's hard to dig them out unless using a spade.
They say the plant is medicinal, good for healing wounds and diarrhea, yet I had to get rid of it because it wasn't something I could use or enjoy, such as plants of a Potentilla fruticosa. And my garden isn't that large to bear such a Potentilla spread, no way!

Extracting a Cinquefoil plant from a coreopsis bush root

The battle with Cinquefoil is going to take years

That's why I started to dig it out before it spread more. It took me about two hours to dig the whole area and pull out the cinquefoil plants. I imagined that somewhere it was growing inside the root balls of other plants, such as the coreopsis or more dangerous, inside a rose bush because that would make it much more difficult to extract. Maybe that's why I couldn't eradicate it properly and some plants popped out this spring again. I might need to repeat the digging, although not on such a large area. I'm sure I won't get rid of it very soon, yet I'm trying. What I don't know is where did it come from and why was it in my garden? That is, of course a rhetorical question! Maybe I don't know where it came from, but what I know for sure is that like all other weeds, the cinquefoil is going to give me some headaches for a long time. But what kind of gardener would I be if I didn't have some hard work pulling out weeds in the spring? And cinquefoil is one of those, trust me!