Encouragaing Reblooming Iris

I bought a Rosalie Figge last year and although it was doing well, it did not bloom in the spring.  I was out weeding the beds and lo and behold, it was getting ready to bloom this fall.  My question is, what do I do to get the rebloomers that I have to bloom?  I'm fine with general iris culture, but not great on rebloomers.

Hi Suzsmile...I have found that a helping of bonemeal about the 1st of September has helped mine to bloom. Have some now in garden.

Always use a high nitrogen fertilizer in the fall (bone/blood meal, Disper-Sul).

This message was edited Oct 6, 2008 10:10 AM

I always thought that irises did not like high nitrogen. Perhaps this is just for high humidity areas.

It may have to do with different soil types. Mine is nitrogen poor.

Nitrogen heats up quickly, so in areas with high heat and humidity, a high nitrogen soil will virtually cook your rhizomes. We have to avoid both high-nitrogen fertilizers and definitely avoid manure for our climate.

I'm a dork - I meant LOW nitrogen fertilizer.

Nothing seems to work here except an early spring and late fall freeze....

So I am not alone having a problem with a rebloomer. I thought the plant maybe hated me! I told my son, that thing not only doesn't rebloom, it hasn't bloomed at all. I suppose it wouldn't help to just stomp on it.

Action the same as jumping on the computer--my temptation.

Rebloomers increase much faster than their spring-only blooming cousins so extra water and food may help. I think that water is the really important factor. I feed all of my irises a month before they bloomed this year with a daylily concoction that I use called Hooker's Formula. It contains liquid iron, fish emulsion, epsom salts, and an all-purpose, high middle number water soluble fertilizer such as Peters mixed with water. Since I feed my daylilies with it every spring, my irises got it too. Then, during the summer when we have high heat and little rain, ususally in late July and all of August, I try to give my siberians, japanese, and rebloomers extra water. The time when we get more rain again, usually starting in September, my rebloomers start sending up scapes. This year was odd though, since September was dry as well until late in the month. I wasn't sure that my rebloomers were going to bloom, but sure enough, after we started getting some nice rains, all rebloomed except Clarence and Plum Wine. PW may still send up a scape or two, even though it's getting really late.

All of these also bloomed in the spring as well as right now - Fast Forward, Immortality, Rosalie Figge, Baby Blessed, Lo Ho Silver, NOID peach, Sugar Blues, Baby Boom, and an SDB that I think might be Smell the Roses.

Suzsmile, don't give up on Rosalie. She was several years getting established for me without regular bloom. I remember that she didn't bloom the next spring after the fall that I got her. She sent up a scape really late, probably in late October, and a hard frost killed the flowers. I don't think she bloomed the next spring, but did bloom the following fall. She bloomed the next spring and we moved her to our new house in late July/early August. She rebloomed in spite of the move and has bloomed spring and fall ever since, and she's full of flowers right now.

I have read that you should never count on rebloom every year, but I've been pretty lucky with my rebloomers. I have no idea why Clarence took time off this year, but I'll no doubt see him again in the spring.

Linda

Thanks Igrowinpa,
I have always wondered what it was like for people who live in places where rebloom happens regularly. I have learned a lot from your post. For instance, I didn't realize that rebloomers increase more rapidly than others. That certainly fits with my experience with Sugar Blues, Immortality and Double Your Fun. It wasn't my experience with Romantic Evening though which rebloomed two years but has not since. Nor does it increase rapidly, but it does increase slowly and has been there for many years now.
I had almost given up on rebloom until this year. Now I have had a fair amount of it. I can't wait for next year. I understand that Florentine Silk reblooms! I bought it because it was stunning and now I hear it reblooms! It did increase rapidly and didn't bloom at all its first year.

After all, irises bloom off the next yrs increase. therefore to rebloom, they would have to have a rapid rate of increase.

Good point. Never realized that on rhizome can't bloom twice, but that seems to be the case.

I'm glad that my comments were helpful to you pajaritomt. While I love all of my irises, my rebloomers are special to me. I love getting a chance to see most of them twice a growing season, especially when many of my other plants are winding down.

The difference in growth rates was especially evident when I planted two SDB's next to each other. Both are in the front of the house landscaping and both started out about the same size in the summer of '07. My Kayla and Baby Boom - the rebloomer - both started out the year looking about equal in size and both bloomed this spring. By the beginning of October, it was very easy to pick out the rebloomer without looking at the tags. BB was SO much larger than MK. It even surprised me to see the difference. I forget that my TB rebloomers have been cut up and shared several times, and still the clumps are nice sized. irisMA is exactly right. To get rebloom, you have to have good increase.

Linda

You have both taught me something. I will be watching carefully for fast increase in the future.
Betty