Violets are pretty, and one kind smells really nice. I liked them for a long time, and tolerated them for way too long.
Trouble is, they are takeover artists, spreading by seed that pops a long ways, and growing slowly while growing roots that hold onto soil really well. We have three kinds in my gardens: the purple or pink flowered one that grows knee-high and has the lovely smell when they bloom; a white one with no scent and grows half as high; and a small purple-leafed one with no scent that gets bushy and wide when seeding out.
The excessive seeding is a real pain in bark paths, where one has to pull each plant separately once they get their true leaves. Stirring the bark up might work when they are newly sprouted. On 4 x 8 paths, they can be killed as seedlings or when still small with a hula hoe, but they have to be hand-pulled along edges up against the rock borders.
Scented violet blooming on a wall in the fall, showing its runners and leaf-curl fungus
The scented one and the white one often have a fungus in recent years that curls the leaves as they start growing throughout the summer. It makes the plant ugly and never allows them to grow to full size, while restricting the number of flowers in the spring.
Fungus-infected white violet in fall
It appeared during the years that our city was neglecting the pear orchard that we bought from Naumes, when a lot of fungal infections appeared around town that are still plaguing us long after the city leased the land to a nearby farmer in return for removing the diseased orchard. Beet/spinach family plants are still growing a nasty leaf fungus that also infects dock and probably came from it in that weedy, diseased orchard, and some varieties of photinia and, of course, pears, caught the black spot that was killing the pear trees.
Purple-leaf violets, crowding out creeping Jenny in the shade
The small purple one spreads seedlings all over my bark and sand paths; the grown plants are occasionally stripped of leaves by slugs and snails; and they actually crowd out my creeping jenny in the shade. The white one spreads by thick rhizomes as well as seed, gets big enough to stick out like a sore thumb in my creeping jenny, and can likewise crowd it out.
Being a perennial, violets have to have their roots loosened to pull them. It’s not as easy as plants with a tap root; these roots are bushy. Crazy snake worms make the soil really loose with their large castings and make pulling them easy where these worms overpopulate from lots of food and water. But get a tool under the center and pry, and they will come out most of the time. Their crown is relatively long and thick, especially where it grows through bark mulch, and you have to get the whole of it to kill the plant. The finer roots probably don’t grow a new plant, but it is hard to be sure. But I don’t chase fine roots. I just keep weeding.
Your small yellow woodland violets don’t seem to take over; they are hard to keep alive in a garden at all. Some plants are hard to tame.
Rycke Brown, Natural Gardener 541-955-9040 firstname.lastname@example.org