Hi everyone, thank you for letting me join the forum.

I love irises but for some reasons I can't seem to grow any colors but white. I was given pure purple and purple with yellow in two separate years. The buds always came out just a little purple then everything turned white once it's fully bloomed. I have done a fair share of Googling on this topic. Most people suggested irises turned white because the colored irises died and the growing spot got taken over by white irises nearby. This might be true to some but the theory doesn't quite fit my scenario.

My first attempt was with Siberian irises, given to me two years ago. They were dark purple in their original garden. They came out in my garden last spring, so pale that they looked almost white. I reckoned I must have gotten the wrong batch.

Last fall, I received some bearded irises from another source. The colors were dark purple with bright yellow. I planted them far away from the Siberian irises, a location where no irises had ever touched. This spring, they came out pale purple then turned white once fully bloomed. The thought of my extremely alkaline soil being the culprit did cross my mind. But again, I had one of them in a pot of store bought potting soil, same thing happened to it... pale purple emerged then turned ghostly white.

I am at lost. Any ideas or suggestions?

to the forum! May I ask where you are located and if you could please provide some photos of the plants?

Also, do you use any chemicals on your garden? Alternatively, do your neighbours spray their garden and might this have drifted into your garden?

welcome to the iris forum canuckgardener.

Welcome. This sounds strange. If I'm understanding you they bloom the right color and then fade to near white? I know a few varieties of tall bearded that do fade a bit, but most often even in hot sun that doesn't happen. Water Waltz is one that fades a lot. You can see the different colors in the photo below.


Do you happen to know the names of the irises you have?
I don't have a lot of Siberians, but never had one that faded. Siberians do like acid soil.

Quite often irises bought from box stores turn out to be the wrong cultivar. Were these irises you bought or got from friends?

I'd recommend that you get your soil tested, and then amend it as needed. Then order a few irises from a reputable dealer, some really dark colored ones and see what happens.

Thank you everyone! Sorry about the delay. Once I logged off I couldn't find my way back in until now.

To answer the questions,

-I don't use chemicals, just compost and aged manure, mulched them over the winter.
-The irises are grown on the fence side, next to a public lane, very far away from other yards or gardens.
-The irises I have were gifted by other gardeners, I was told they were Siberian and bearded irises. The first batch I received were Siberian Irises and the second were bearded irises. I didn't get to see the Siberian irises bloom in their original garden but was told they were dark purple. The bearded irises were dark purple and bright yellow. My friend took a picture of their blooms to see if I liked them. I am pretty sure they're yellow and purple.

I am in Calgary, Alberta, Canada. It's zone 3 here and I have clay and alkaline soil, very typical in Calgary.

Recently, a mutual friend gave me some yellow irises, came from her garden. I will plant half of them and give half to a neighbor down the street. Then we will compare results next year. If mine turns out white while my neighbor's comes out yellow, it must be the soil.

https://www.historiciris.org/a...

https://www.historiciris.org/a...

That was the first article I found online but none of the suggested scenarios explained my case.

Question to Canuck Gardener: are you remembering to deadhead the blooms after they finish, so that your garden doesn't get taken over by no-name seedlings which may have unexpectedly different colors than their parents?

Hi Canuckgardener, - I live out in Ontario and have much the same soil as you do. Over the past few years I have noticed that all of my purple Irises have transformed into yellow ones. Given that I am not particularly fond of yellow irises, I am sure that I have not planted any yellow ones, so this is not a result of any of the commonly proposed issues. Digging deeper into the biology, chemistry and genetics of flowering plants - I believe I can explain what has happened, but as to why - I am still searching. Flower colours are the result of different levels of 2 different "chemicals" - anthocyanins - which produce blue, purple, burgundy/red pigments and Carotinoids which produce yellows/oranges. If for some reason, the plant is not able to produce adequate amounts of anthocyanins, then flowers which were originally purple or burgundy will loose these pigments and become yellow if carotinoids are still being produce or white if they are not. If this is the case, then it is unlikely that yellow Irises will change colour. Most of the reports I have found are of Purple Irises becoming yellow or white. I would be interested to hear if anyone knows of Yellow or white Irises changing to purple or other colour transformations.

The question is - why do the flowers stop producing anthocyanins? This is the question that I am still searching for answers to. Given that we are both struggling with clay/alkaline soil, perhaps it is due to pH but other options include temperatures, water, trace minerals etc. If I find out anything else, I will let you know.

Welcome Mayodog2

I know an iris of another color could "take over" a planting, but it seems to me you would see two different-colored irises for at least a year or 2 until the more vigorous one took over. So I have wondered what the cause would be in the cases where a complete color change occurs in a year. And now that you mention it, it does seem that these cases are always purple to white or purple to yellow, not the reverse.

I read somewhere that the anthocyanin production in grapes was inhibited when grown in a medium high in ammonia, so there might be something to the fact that these irises are losing the purple color in alkaline soil.

I'd be interested to hear what you find.

I'm wondering if the person(s) you got the iris's from, originally, bought a pack of the sib. iris that were a mixture of yellow, purple, and white (as they often are packaged). It could be possible that you had all 3 colors at one time and the white ones were stronger and the only ones that made it through over the years.

Many years ago I purchased a packs of all 3 colors. In my case it's the purple ones that won out.

Canuckgardener,
Over the years I have read this same scenario several times from people about their iris were purple and now all they have are white iris.No one has been able to definitely solve the mystery it seems.There was one that went from yellow to white I remember seeing.
All the ideas have pretty much been the same,did you deadhead ,etc.It seems one year they are purple and the next all are white.These are older common iris varieties I am referring to.

It has, in fact, been solved. People just don't like the answer so reject it. I recently saw it happen to someone who lives a few blocks from me. They had a nice big clump of what appeared to be Pink Satin (it's hard to say for sure since the Sass brothers introduced several similar irises) growing in the strip between their sidewalk and the street. There's always a number of bee pods in the clump when it's done blooming that don't get removed. In 2018, a single stalk appeared in the middle of the clump with white flowers and a second one had yellow flowers. These were obvious seedlings growing within the existing clump. The homeowners apparently didn't notice because they didn't make any effort to remove the seedlings. Last year, there were a lot more white or yellow flowered stalks. By this spring the clump had about 75% white flowers and 25% yellow flowers. The seedlings were able to completely overrun the existing clump within two years of first bloom. For anyone not paying close attention, that would seem like an instantaneous transformation.



There's a couple of reasons why the supposed transformation always seems to be from purple to white or yellow. The first is that white or yellow flowered seedlings will pop up from all sorts of different colored parents. For example, if you cross a pink iris to a blue iris, you'll get a boatload of yellow seedlings, fair number of white seedlings, and a very small number of other colors. Put simply, it's easy to get white or yellow flowered seedlings from purple parents. It's more difficult to go the other way. White or yellow parents don't produce purple seedlings (unless the pollen parent provides the genes for purple of course). The second reason is that when a purple seedling overruns an existing purple clump, people don't notice. When a white or yellow seedling overruns a purple clump, it's hard to miss.

The reason why this seems to mostly happen to older irises is also pretty straightforward. In modern TBs, the gap between the fall petal and style arm is usually so large that it's difficult for bees, even big bumblebees, to deposit pollen on the stigmatic lip. Bee pods are much more common on older varieties.

A clear and well-written explanation, Kent.

Australis said:A clear and well-written explanation, Kent.

Kent and

Thank you! I didn't know that about the newer varieties (fewer bee pods). Very interesting!

Kent, for your explanation

I figured it was bee pods and seedlings as others thought, but when I read the question from a puzzled gardener over the years ,they made it sound like it was 1 year it was purple or yellow,then the very next season it was white.
I couldn't figure out how seedlings grew to standard size in a year's time and overtook the clump.

I divided and transplanted all these from one clump that was always violet purple. The first year, I had a new white variant. This second year, half are white. The violet veining in the white ones exactly matches the tint of the solid violet ones. Meanwhile, an older clump of all-violets have remained the same. The biggest difference I see in location is the white variant appears where grown in day-long full, hot sun.

FYI, thread originated 2019