Cutting Back

This question was put to me by my mom and I told her I would ask you all, the Iris Experts. When and where can you deadhead after a bloom is spent? How far down the stem would you cut? Now here is her real question. She has some rebloomers but has no idea which ones are rebloomers, she doesn't want to cut them all down to fans if she has some rebloomers in there. So she wants to know is there any way to tell a regular TBI from a Reblooming TBI? She has been going crazy in her yard sense my dad went to heaven nine weeks ago. She is ripping all sorts of stuff out and wanting to plant new. I am glad for it though being outside is really good for her, gardening is so theraputic. Thanks in advance.
~Dayna

I'm very sorry for your and your mother's recent loss. I'm very glad that she has her garden to keep her busy during this time and that you are there to help get answers to her questions.

Generally, the spent bloomstalk is snapped or cut off right down at the rhizome.

All rhizomatous irises, including bearded rebloomers, have the same life cycle. Each rhizome will only bloom once in its lifetime (yes, even the rebloomers). In most cases, the rhizome will also grow new rhizomes (increases) along its sides. The increases grow to maturity, then bloom and repeat the cycle of of increase. Eventually the bloomed "mother" rzs will exhaust their energy and dissolve away into the soil. That's how a single rz turns into a larger clump over time.

While most bearded irises are genetically programmed to bloom only once per growing season, rebloomers are capable of blooming at different times during the season if conditions are favorable (if the clump contains mature, blooming size rzs; if there is adequate nutrition and moisture in the soil; if the plant is healthy; if the growing season is long enough; etc.). No iris is ever guaranteed to rebloom; there are just too many cultural and climatic factors that influence rebloom for it to be a sure bet. And most rebloomers only do so in the areas with the longest growing seasons.

In any event, your mom doesn't have to worry about the effects of removing spent bloomstalks on potential rebloomers. They won't rebloom on the same rzs that they already bloomed on, anyway.

If you know the names of the TB cultivars your mom is growing, we can probably tell you which ones are known to rebloom.

Laurie

I theoritically have 23 'rebloomers". On my best year, I have seen 6 rebloom in the fall. My summer is just not long enough for most of them.

On the other hand, lillyfan is in southern Iowa and has heavy iris rebloomers starting in August. Her growing season is just a bit longer than mine.