Advie Needed

I purchased 5 bulbs of Sternbergia Lutea which happen to be Zone 6 (-10 F), however I am in Zone 4 (-30 F). How can I make these bulbs work. They are fall bluming bulbs. When I got them they said for fall shipping so I suspect they are intended to be planted in the fall. I though I could plant them as soon as I could dig a hole in late winter/early spring but I am not sure. I then thought I could try planting them now and covering them with lots of grass/leaves/mulch... Or lastly I thought I could plant them in a pot now and keep them in my back room that only reaches temps as low as 30 F, finally to transplant them where I want them in the spring or to keep them in the pot. I really want to have them in a small rok garden for the fall.

Please advise on safest approach, including ones I have not thought of!!


http://www.waysidegardens.com/webapp/wcs/stores/servlet/StoreCatalogDisplay?storeId=10151&catalogId=10067&langId=-1&SearchText=8092&mainPage=textsearchresults&RequestType=NewRequest

I found this site, hope it helps. Scroll down to 'Specific Instructions' and click on it. Then scroll to the bottom right of the third page, to 'Sternbergia, Lily of the Field.' The article continues on the next page, top left, like a book. A bit confusing at first. I was going to copy and paste but it wouldn't cooperate for me. :) http://www.whiteflowerfarm.com/gardening-in-autumn.html