canna can not take frost or freeze ... pot them and keep them in the garage until about mid may .... depending on forecasts .... 60s during the day and low 40s at night is perfect for dividing and moving in z5/6 ... just do it .... thru about the same mid may ... warm days warms the soil for roots to pump water... and cool nights give the plant a few hours to rest and regain water... for the next day ... cold days and cold nights basically suspends animation .... hardy perennials should not care about frost.. and though they might be damaged by a hard frost.. will most likely survive ... just do what you need to do.. and dont worry about it.. the only way to turn your thumb green is to just do it... and you arent a gardener..until you have killed every plant three times. ... we have all done it... so just DONT WORRY ABOUT IT ... good luck have fun ken

You can move and divide them at any time. I had a very overgrown flower bed that I needed to renovate. I dug up everything and replanted. Some of the daylilies bloomed in the temporary pots (with just a little soil thrown over them) before I even got them into their new location. I have even heard the recommendation to move and divide them while blooming to be sure you know what colors are going where you want them. I didn't wait for mine to bloom before moving them but as I said, some bloomed anyway, so I was able to place the colors exactly where they look best. Were they set back? Yes, the stems were shorter than usual on some.

I agree with iris_gal. In addition I would say that you should only move them if you have to. A local woman sells them while in bloom. While it's great knowing it's what you want it does take it's toll on the plant. Years ago she instructed me to cut the flowers once I had labeled them, because they will just die. Since back then I was even shocked to hear of trimming back the leaves(to height of 6 or 8 inches in an inverted V shape ^ ) I didn't follow her advice. The flowers wilted and the leaves weighed down the plants (toppling several). Luckily I was able to save the remaining buds and enjoy them in a vase. I still buy from her each year, but I always expect them to be even more unsettled than the rhizomes sent at the proper time. I don't know siberians well enough to suggest a good yellow, but I do grow i. pseudacorus. It's considered invasive by many and is banned in some states. I grow mine along-side my TB's and it's never even started to crowd anything. Since I'm too inexperienced to execute a proper soil test(as anyone should) I use a generally accepted fertilizer. I buy mine at Walmart with the numbers 6-10-10. I can't say it's the best for everyone, but at least it hasn't harmed my plants. I realize that I ramble, but I hope I've helped somehow. Brock

My experience - which may not be what other iris growers have learned - is that the very mildest of frosts does not stop the settling-in process. When I planted a large quantity of iris very late one year, I had one unnamed variety that I used as a sort of control. I planted eight of them and dug one up every week to inspect it. This is what I observed. At one week, the dried out roots had started to swell up a bit, a nearly negligible amount. At two weeks, there were the tiniest new roots beginning to bud on the bottom of the rhizome. Average temps during this time were still in the high 50's to low 60's at night. I kept the soil lightly moist during this time. By the fourth week I had some substantial new root growth and the rhizomes felt 'anchored' when I tugged on the leaves gently. It was not until the sixth week, by which point the temps were occasionaly in the light frost range at night, that I saw any new leaf growth. The iris that bloomed the following year were generally those that had some new leaf growth in the fall - the others were fine, but just didn't bloom the first year. When I plant earlier in the season, the root growth seems to happen a little bit faster, and then there's more time for the foliage to grow after the roots become somewhat established. Understand that this wasn't a highly scientific experiment, just some observation over a few weeks in one particular year of late planting. Hope this helps though. katie