Ageratum

In the mid 1980's I brought some Liriope up to the lake house from my home in Decatur Georgia.  I did not realize it at the time but I also brought the beginning of a whole new generation of blue flowers which have spread over several acres taking hold where they pleased, and the mower did not get them. 

I have no idea how this blue plant, Ageratum, happened to make it's way up here in the clumps of Liriope which I planted as a border, in the front of my home.  The first time I noticed them was when they popped up in the Liriope the next spring. I did not even know about this plant.  I had seen smaller versions of it in Nurseries, but had never seen it growing in other places. 

At first I tried to get rid of it, not by spraying herbicides on it, but by digging it up.  I learned pretty soon  that the web of interlaced roots had no intention of leaving their chosen spot.  Therefore, I just let them do what they pleased.  What they pleased to do was find new places where they would send their seeds and start new colonies of Ageratum.  Every spring I found new places where they had chosen to take root.  This was brought home to me the other day as I was driving down our road toward my entrance when something blue caught my eye on the edge of the woods.  Yes, it was the same blue flower which has popped up on my hillside, the long driveway, down near my raised beds, and just this summer at the corner of my house near the drain pipe, as shown in the photo.

By the persistence of this plant I would guess it is classified as a weed, but not necessarily.  It is identified as Ageratum houstonianum.  It can be purchased in colors ranging from white to lavender-blue.  Seeds are sold for annuals and perennials as well.  It ranges in height from 6-8" and up to 18 inches.  I think you could call it the lazy gardener's plant.  It certainly does not require any help in propagation, or in thriving.  In fact it is hard to stop.   One type is called Hawaii White, common name "White weed", yet the seeds are sold along with the blue and other seeds.  So whether you call it a weed or a flower, is up to your attitude.  I am ambivalent on this point.  I like it as a flower but I would like it better if it would grow only in the woods or along the edge of the woods.  My attitude is that it is pretty and requires no help from me so I just let it be.