Why wait six weeks with transplanting iris?

21 years ago

I planted some bearded irises 1 or 2 years ago that I had purchased without knowing what their colours would be (they were mislabeled and not any fancy varieties). Some of them are blooming now so I learned the colour and also that I need to move them because the colour does not look right where they are planted. E.g. dark reds and violets in the far away half-shaded beds are not visible at all so I want to move them closer to the entrance of the garden so that I do not have to go out and look for them to admire their flowers.

I usually have little time to garden in August, so I would like to move them now - right after they are finished blooming. There is a lot of rain this spring and I am also willing to water them throughout July.

I am not sure what the six-week waiting period after flowering is meant to accomplish? Will I weaken my plants if just dig them out now?

And, should I cut off the flower stalk while transplanting? I thought the flower stalk should be left on the plant because the growing rhizomes feed on it but maybe I am completely wrong?

Thank you for your advice.

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Comments (5)

jain
21 years ago
i move and divide iris right after they bloom because i have so darn many i need to start early. NO adverse affects here! when i divide i discard the flower stalks, they can make babies, but i have too many fresh new plants to need to nurse a spent stalk. i also have a longer growing season then you do, so don't think you should keep them...
laurief_gw
21 years ago
Go ahead and dig now. You won't hurt the irises a bit. Remove the spent stalks and cut back the foliage just enough so the plants can remain upright after being replanted. If you replant them with their full foliage, the weight of the leaves will tend to keep tipping the unrooted rhizome over.

You can check the FAQs (link at top of forum page) for detailed instructions on digging, dividing, and replanting.

Laurie
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garden_of_mu
21 years ago
The 'six week' guideline applies to established clumps that you want to divide into individual fans. The reasoning behind it is that six weeks gives the new increases time to mature, so when divided they are large, healthy and ready to go. If just moving a small clump or single rhizome I do it anytime of year if I can get a whole rootball.

Folks in cold climes may want to divide sooner as established root systems before winter are more important than mature rhizomes. Similarly, folks in southern areas may want to delay until fall and cooler temps to divide and replant. How you handle your irises will depend on your conditions - there are few hard and fast rules that will apply equally with everyone.

Mike
anna_beth
Original Author
21 years ago
Thank you - just what I needed to know. I understand if move the small clumps now, they will first establish the roots back in the soil, and then proceed to grow new rhizomes. Anyway I just will not wait until August :-)

Jain you have fields of iris - our botanical gardens do not have as many as you do. And the roses.. Such a beautiful garden and never any dark, short winter days - that's life! :-) By the way I also have a blue and yellow bed with fiery red accents (iris + clematis + vinca + lamiastrum + poppies) and the colour combination does look great. Your garden and the countryside - which reminds me of the Canary Islands - are just breathtaking. I very much enjoyed a visit!
jain
21 years ago
thank you anna beth, i am so glad you enjoyed a garden visit! i don't have fields of iris, although if i had level land i would think about it! i have thought often of visiting the canary islands, what a fun comparison! thanks for your compliments.