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

Generally, it is not a common practice to divide anything that is still flowering. Some plants can be divided soon after flowering. Waiting six weeks for your irises seems to be good advice to me.

If your pot has a smaller opening at the top than its largest circumference and your agapanthus have filled the pot, your choices are limited. Since you want to preserve the pot, some of the agapanthus are going to have to be sacrificed to get the rest out. You certainly can cut them up while they are still in the pot--to divide them, you would be doing that anyway. To make it easier to see what you're doing, you might want to consider hosing or soaking out as much dirt as you can--definitely a task to be undertaken out of doors. Again, if you were planning on dividing them, removing the dirt would probably be something you would be doing. Don't soak them long enough for the roots to swell-that will make it worse, perhaps much worse. Once you can get a clearer view of the situation, I'd take a look at the clump and wiggle things around a bit. Then I'd see which ones are smallest and wiggliest and start there. Once you've gotten a few of them out, you might get lucky and be able to take out the rest of the clump as a whole. Otherwise, just keep rinsing out more dirt and wiggling or cutting pieces free. Kay PS: When you replant, I'd definitely suggest using a different pot. Agapanthus can multiply rapidly when they're happy, and jacking them out of a beloved pot is probably not a task you'll want to repeat.

Around here the iris society digs in July for their annual sale. I looked up on line to see the proper time & there is completely different information, maybe it depends on the area of the country. I've read 2 weeks after blooming, late summer, early fall. The site I tend to go with said any time after blooming, it works for me. I know I have divided even during bloom up til November here. There are some iris that just don't like to be moved, & I know which ones they are now, but generally they all have bloomed the following spring. The ones I got the least amount of bloom on were the November ones.