I fought wild morning glory for 18 years in my veggie garden at my old house. I used everything I could. I even left the garden bare one year and sprayed it with roundup every week. The morning glory reappeared the next
spring - worse than before. I still had great production, it just took constant digging and pulling to keep the morning glory vines from choking everything out.
If I went on vacation for a week, I would come back to a garden that looked like all I planted was morning glory. Then I would have to spend 2 days digging, pulling and unwinding the vines from the tomatos, green beans, brussel sprouts, etc.
Last week I found 2 morning glory sprouts in my mum bed here at my new house - I've hit them with roundup every day since then. They are almost completely dead and I'm still painting the them with roundup every day - just in case. Morning glory is the Japanese Beetle of the
plant world.