The cut part of the rhizome will grow no longer in that direction. I place the cut edge facing the edge of the bed. The new growth will then grow back into the bed, as opposed to growing and advancing 'out of' the bed. The new fans will grow back from and out from the rhizome you are now planting. It will in time be the 'mother' to new fans.

Sue

thnak you so much for the explanation. i can't believe how ignorant i am sometimes! now to find room for all my new beauties (some gorgeous dwarf ones, too). can't wait til next year to see how they look! =)

I learned rhizome placement the hard way...not giving it any thought, or asking anyone...but that was long before I had a computer and Garden web.

Also, in hot parts of the country, it is suggested that the toe of the rhizome be planted toward the north northeast, so that the fan will shade the rhizome during the hottest part of the day.

Wow! Thanks for posting this question, Roxanna! I had no idea! I only just started getting into iris last year and I have been planting them all wrong! The exact opposite in fact! Glad I saw this today before my iris order gets here. Thanks!

Aunt Lou

I'm with Aunt Lou on this, Roxanna. You weren't ignorantÂyou were smart to ask this question. I should have asked it myself before I planted so many iris.

I have been growing irises for over 20 years and didn't know that either! No wonder my beds were so crowded. I was planting the opposite direction. Thanks!

Interesting topic. I always just automatically planted them with the fan at the back of the bed and the "toe" toward the front because I wanted the flower scapes to "look at me". My experience is that the scapes come up on the side of the fan that is closest to the rhizome.

Not to throw a wrinkle in this, but I had some iris that were growing in the shade covered by an agressive vine for many years. Had not bloomed in at least 5 years.

I finally dug them out last fall and found 2-3 ft long rhizomes per fan. They were so long that I just cut them into 8-12 inch sections, most w/o a fan, and put them in the ground. This spring they grew new fans all along each side of the rhizome pieces. Some have 8-10 new fans like little rows on each side. So, I think they sometimes don't grow just toward the back.

I finally dug them out last fall and found 2-3 ft long rhizomes per fan.

Mercy. My experience has always been that anything past the mother rhizome (the one with the existing foliage) just had the dried up roots. I guess if they don't bloom, then that rhizome does not qualify as a 'mother'....maybe?...so her roots don't dry up?

That's very interesting how your 8-12" sections grew so many new fans.

So, I think they sometimes don't grow just toward the back.
I agree...they grow from the back (heel) and from the sides...so one needs to take that into consideration when spacing them apart.

Sue