Question: I live in Olympia WA, on black lake I have a doozey for you! I have been battling morning glory vine for nearly a decade. How do I get rid of this beastly vine. The root system is so broad and vigerous, it seems impervious to round up, vinegar, spectricide ect. I have tried to control it by plucking it as far down the vine I can dig, but seems like that just empowers it? Have even tried to eliminate light, still the beast lives. Any suggestions? Lisa Menge
Answer: Your are right Wild morningglory (Convolvulus arvensis) is a beast of a weed. The roots can penetrate down to 10 feet in some soils according to WSU extension. So once established it will develop an extensive root system that is a formidable oponent. It will spread by seed as well as from its root system that will persist year to year (perennial). Because of the extensiveness of the root system round up will only kill back so far and the remaining root system will re-sprout (it reportedly can do so from five feet below the soil surface!). Your plucking effort probably did not get nearly all of the root system. The vast root system not only can regenerate new shoots but is also a vast energy reserve which you must deplete over time. Most herbicides will only kill it back so far and then it will resprout from the remaining root system. So the plant must be continually starved and given no quarter. Continual diligence to prevent it from creating new above ground shoots is imperative. This will take time (I know you have been battling it for many years but the morning glory has been more persistent than you have). You said you have tried to eliminate light – but if it survives you were not successful. It must receive no light (like heavy black plastic mulch that overlaps and no holes for plants where they can peak through). So a combination of spraying or weeding any above ground growth regularly (no more than a few inches of growth should be allowed to form before they are removed). Just think if it doesn’t photosynthesize it will eventually deplete it’s energy reserves but it could take a few years of due diligence. Sorry no magic wand for this beastie.