Stephen in Brantford, Ont., asks:
What is the quickest way to eliminate periwinkle?
One option would be to solarize the area where the periwinkle (Vinca minor) is growing. This is a viable option if no other plants you want to save are in the area, and the area isn’t too large. Solarization involves cutting back all growth to ground level and then covering the vinca with thick layers of cardboard or black plastic and weighting down the edges to prevent the material from blowing away. This starves the plants of sunlight and water (in the case of plastic), and eventually they die. The key word is “eventually” — it may take several months. Another option is to cut back all above-ground growth, dig out what you can and do this repeatedly until the plants eventually give up and you’ve eliminated all of the roots. Admittedly, this is a manually intensive solution, but not too onerous. Periwinkle, although persistent, isn’t as difficult to eradicate as goutweed (Aegopodium podagraria) and its variegated version. Good luck.