I'm in zone 5 too - and have the Limelight Artemsia in one of my flower beds. I love it - it's a slow spreader for me, and as Connie says, I like it well enough that I don't mind yanking a clump if it gets unruly. It's actually growing well with other plants. Here is mine growing behind this peony ~

If you decide you don't want those Star of Bethlehem, I'd gladly take them off your hands! LOL!

I don't have any of the Lysimachia - loosestrife and agree with Connie again.

DizzyD %-}                   

  Seeds for SASBE

I have all of these, except Loosestrife, and I am in zone 5.

Some have claimed Star of Bethlehem to be invasive, for me it isn't. It has remained in a single clump for 5 years. Two of my friends have it and they find it friendly also. The key may be to avoid disturbing the clump so the bulblets don't spread, or plant it in a pot.

Purple loosestrife or gooseneck loosestrife, I would burn it with no regrets. It is an invasive species that is harmful to native areas if it escapes and it's very hard to control. This type of Loosestrife is Lysimachia clethroides.  Other types of Lysimachia are not as invasive. I have L. punctata and find it slow to spread, but there are several other species, too.  

Limelight Artemisia is an aggressive spreader. I like it, so I don't mind yanking a bunch of it out every year to keep it in check. But, if you prefer clumpers, this is not something you want in your garden. Several gardeners I know have removed it because of it's aggressive habit.

It would be great to hear other gardeners experience with these plants, too.  

~ Connie    ~ Zone 5    ~ MN 

will you be able to control them by planting them in pots and keeping them deadheaded? I am sure someone else will know that had some experience with them but just an idea.