Question
Tom,
 I live in northern Wisconsin (Hudson). I bought a house last June and there is a Southern facing bed off the deck.  It was full of overgrown weeds when we moved in.  Since then I've hacked the weeds, tilled soil, planted bulbs last fall.  Had some luck with the bulbs but this is where it gets interesting.  I kept up with weeding and eventually the weeds took over (so I thought).  One morning I walk out to beautiful Pink Morning Glories?!  What a great suprise.  Anyhow, I was wondering what could have caused this.  Since I have removed all other weeds and given poles for the vine to grow up onto the handrail of my deck.  The flowers are pink, I matched the leaves to confirm this is a morning glory specie.  My questions are first, How after I weeded, tilled, and sprayed gallons of week killer do these wonderful plants begin to grow in late July?  Also, is there a chance these could be perennials? If not I'm going to harvest seeds and start early next spring.  I can't seem to pinpoint exactly what specie I have but I'm certain they are morning glories.  What answers can you give me?

Answer
Hi Joe,
Thanx for your question.  Morning glory seeds are very hard and can lie dormant for years before being disturbed and then germinate.  They may have been buried underneath all the weed growth and then when you cleared it, they were stimulated to germinate.  Morning glory seeds can also be deposited by animals like birds.  Morning glories are natives of Mexico that have naturalized through much of North America.  In Mexico, they are perennial but grown as an annual in most of the U.S.  In some areas, they are considered a noxious weed because they can be invasive and take over and choke native life out.  A lot of times, weedkiller does not necessarily penetrate the hard coating of a morning glor seed and so it survives the treatment unscathed to germinate at a time more favorable.  If you really like this morning glory and it doesn't get out of hand, saving seed is easy.  You will see the brownish seedpods that look like large peas.  There are usually 6 or 8 seeds inside.  They are usually black and hard coated.  I hope this helps.
Tom