They only spread by the seeds blowing around. They will bloom in semi-shade but do best in full sun.

Karen, It's proper name is Lunaria Annua, common name Honesty, Money plant. I have a better picture of a large one on my pictures. If you can recall the plants that used to be in dried flower arrangements.. They look like silver dollars you could see through. I don't know where you can buy them. I don't have any seeds or I'd send you some. I'll have plenty in about two months. You must plant them one year and they'll bloom the next. You could plant them in the fall.

Karen, the purple plant is called Honesty, Money plant and several other things.. thanks for the nice comments.

YOUR FLOWER BEDS ARE SO BEAUTIFUL... THANK YOU FOR SHARING.

I'm probably tiring you but here is one last one, another favorite white cultivar called Madame Emile Mouilliere (spelling is right on the picture) http://www.garden-share.com/photo/hydrangea-macrophylla-madame

If you put it's name in the search area you'll see 3 different pictures of it at 3 different stages...this is mid stage. The first stage the bloom head is totally white, here in the middle stage you see hints of blue in the center and the last stage much darker blue with the white. Nice contrast I think. If you want more recommendations like this just let me know.

...and how can you not love this one?  A lacecap with long tubes to the double sepals. Fuji Waterfall http://www.garden-share.com/photo/hydrangea-macrophylla-3

You may not know this but the big sepals look like flowers, but they aren't - they are there to attract pollinators to the actual much smaller flowers in the middle. Likewise for Dogwood trees - a lot of folks think they are looking at the flowers (big white sepals) when in fact the actual flower is in the middle and are not the with sepals.

Here's another one, more common, but variegated and this time a lacecap - H.m. 'Mariessii' http://www.garden-share.com/photo/peak-hydrangea-macrophylla-1

For example here's one of my favorites - hard to find - hard to propagate (not sure why): http://www.garden-share.com/photo/hydrangea-macrophylla-brunette

Here is the other: http://www.garden-share.com/photo/hydrangea-macrophylla-endless

By the way, if you go to the photos page and put endless summer in the area that has a magnifying glass by it and hit enter you will get pages of pictures of this particular variety in various garden settings of members here. You'll see it's quite common. Whereas if you put many of the cultivar names I have you won't get very many hits besides the ones I've posted. Big box stores have pushed Endless Summer, Blushing Bride and a few others - mainly a big marketing strategy for remontant hydrangeas - for the Yankees - but like I said before there are many others that I think are much more beautiful and interesting.