I think, wait until next year. They are building roots.

Iris often take a year to settle down. Be careful with iris psuedacorus, yellow flag. It's very invasive and will outcompete many native plants including our native iris versicolor.
It is currently on the state of NH's banned plant list. So bad there is no growing, trading, transporting privately or commercially.

We have native blue flag iris in Alaska. They take two years to start getting blooms and a few years till they have a lot of blooms.

I know you posted this awhile back but here goes, Your flags should bloom next year, at least mine did the second year. And as a note when they do bloom do be sure to dead head to prevent them from going to seed and spreading to other areas downstream.

Well this may be a better late than never post, but I wanted to chime in on the invasiveness of this flag. I got a single rhizome of an unknown iris 2 years ago and planted it in a regular perennial bed. We've had so much rain the past 2 years it was a great spot. This year it bloomed for the first time - which lasted a short while, but the plant grew to mammoth proportions - it was fully 4.5 ft tall and the leaves spread out maybe 5-6 feet across. I dug out most of it at the end of summer and tried to give it away - nobody would even take it. Its got a pretty bad rep. Would you consider one of the camassia or Japanese iris instead? Also, pulmonaria, virginia bluebells, bleeding heart, ligularias, and I'm having a mental blank out on the little many colored flowers that start with "p", bloom in spring and intermittently after - love moisture. Also, a solid planting of ostrich fern, cinnamon fern, or lady fern is spectacular at the waters edge.

With flag iris i would consider digging it up every couple of years and just put a bit back in the ground, this has a reasonable controlling effect over them.

Thanks for all the info. I will be careful to deadhead and dig up, if necessary, to control. Mine looked awfully straggly by the end of fall, not like something poised to wreak havoc. But I will keep an eye on them.

Depending on where you are in NY your iris may or may not end up invasive. Normally they aren't too bad around here, but we have some awful winter cold which may control them some.

Hi-In defense of yellow flag, I have some growing that are at least 40 years old and they arent a bit troublsome. I live in New York state. I think that the reason they arent a problem here is the incredible amount of rich lush growth-there is an awful lot to compete with and few are going to get very far with the golden rod and asters surrounding them. So perhaps these are factors to take into consideration in choosing to grow them or not.

Also, mine only flower if they are directly touching water in the spring. I dug trenches that both drain the overly wet meadow and bring enough water for the flag to flower.

I also have blue flag. They do not bother each other at all. They spread, but in 40 years they have spread to a 7-10 foot radius (hard to estimate without looking). That is hardly a problem where I live, though I guess if space is very limited it could be.

LVX
Laurette

I do see that Yellow Flag Iris is listed on the Massachusetts Invasive Plant Evaluation List. I think I am learning that what happens on my property may not be the same as what happens elsewhere (look of chagrin). Reasons may be the many small microenvironments and number of competing species.

I just am stubborn and hate to think of plants I cherish in a negative light. I will refrain from sharing rhizoms or seeds.

PAX
Laurette

Planting ,or propagating yellow flag is always a big mistake.If you think otherwise maybe you should check out a web site devoted to educating people about the destructive potential of invasive weeds.Yellow flag IS a prime example of a plant you should be eraticatng.And putting in your garden will not impress anybody that knows better.

Aned yes it is very invasive in New York.I suggest anybody posting information on this site do some reserch first.