What is expected in an iris trade?

Maybe this sounds dumb, but I just dug some Iris this morning for a trade, and this question came to mind. When you dig, you will usually have the old "mother" rhizome, and then two smaller ones attached to each side where the fans grow out of. When trading, are you expected to discard the "mother" and send one new one as the trade, or do you send all three pieces intact and let the trader do as they wish with them??

I've been replanting my iris for years, but just never gave a thought to what might be accepted as an "iris trade". I hope I haven't insulted anyone by sending the "mother" along. ( The mothers have nice fat roots also, so they must have some value to the plant.) Thanks, Legit

Well, the answer is neither of the options you have mentioned. Here's how bearded irises work. You generally buy and plant a single, mature, blooming size rhizome. That rhizome will bloom once and only once in its lifetime. However, it will also, in most cases, grow additional rhizomes (increases) along its sides. These increases grow to maturity, bloom, and grow additional increases along their sides, and so on and so on. That's how one rhizome eventually grows into a large clump. A mature clump of bearded iris will contain rzs at all stages of maturity: old, barren mothers; mature, non-bloomed rzs; immature rzs; and little nubbins just starting to grow along the sides of larger rzs.

When trading bearded irises, you should trade the largest unbloomed rz in the clump. That way you are trading a rz that is as mature as possible and offers the greatest bloom potential for the following bloom season. Mothers that have already bloomed offer no bloom potential, and mothers with immature increases may not bloom for 2-3 yrs. If you trade mothers with immature increases or just the immature increases themselves, you should always inform your trader ahead of time so (s)he understands that bloom may be several years away.

It's fine to toss in old mother rzs as "bonus" plants with a trade, but they should never be considered part of the primary trade. Small increases should also be considered bonus plants. Send the largest unbloomed rz you have for the trade, and your trader should be well satisfied.

Laurie

Thanks, Laurie,
Here is the question...of what value is a "mother" if it has no bloom potential?
Also, I have dug and transplanted quite a few iris this fall, and I only have two options, "mothers" and the ones attached to the side, one on each side, forming a "V", they are about half to 3/4 the size of the "mother", so they must be next year's blooming rz, right? Legit

Wow, lots of information here that this newbie did not know! I had no clue the same rhizome would not bloom repeatedly.

How do you tell which rhizomes are the barren mothers?

Edited to add... Do the barren mothers still continue to produce offshoot rhizomes? If so, then they could produce a blooming clump in a couple of years, right?

This message was edited Sep 19, 2005 5:34 PM

This is so informative, I had no idea that once a mother blooms it never blooms again. Great explanation of this. Even my Iris book doesn't state this.

There are no hard and fast rules where iris growth is concerned. Some mothers will produce just a couple of increases before they start to decompose and die, while others may produce a half dozen or more increases. In some cases, you can remove mature increases from a mother, replant the mother, and she will continue to grow even more increases. In some cases, a rz will bloom and never produce any increases at all (a condition known as bloom-out) and will result in loss of the plant. Although bloomed mothers have no future bloom potential themselves, they are worth replanting (if you have the extra garden space) in hopes that they will continue to grow increases. You just never know what a mother may or may not do.

Generally speaking, mothers with no viable roots and no foliage are probably at the end of their reproductive life cycles, although I'm sure there are exceptions.

One of the problems we northern gardeners face in growing irises is that our growing season is so short that increases often can't mature in a single growing season. That's why less vigorous clumps or immature clumps often don't bloom every year in my garden. If the increases on your mother are only 1/2-3/4 the size of the mother, they may not have enough time to grow to maturity before next bloom season, esp. if you are talking about TBs. Dwarfs and medians tend to mature much more quickly than TBs.

When I dig rzs for sale or trade, I dig the ones with the largest fans with the most leaves. They are the ones with the most mature rzs.

Laurie

Thank you Laurie for all of that information, I definately will pay closer attention to what my iris are doing next spring. I am also going to replant some of my mothers to observe what they will do. (just can't resist yet another experiment!) And yes, I have seen mothers with no roots at all, and some with roots as vigorous as the new rz.

Does the huge fat mother with the nice fat roots continue to feed the new rz into the next season if not separated? Or is it better to remove the new ones and plant each separately?

Then as long as we are this far, and know we have a shorter season than some, what can we do to fertilize, or promote the growth??

Thanks for the help! My iris will thank you too!! Legit

I assume that a mother rz will continue to supply nutrients to her increases as long as she's alive and kicking. In our short season climates, I would think the increases need all the extra nutrients they can get, so I wouldn't recommend removing immature rzs from the mothers.

I recommend fertilizing in spring about 6 weeks before bloom and again immediately after bloom. Do not fertilize later than July in cold winter areas. You don't want to promote lots of tender new growth that may get damaged by the first fall frosts.

Fertilization should be done according to recommendations on a soil analysis done of your garden soil. Overfertilization can poison both your plants and your soil. It's always best to err on the side of underfertilization. It's also safer to use natural fertilizers such as compost, well-aged manure, and alfalfa meal or pellets, all in moderation, rather than chemical fertilizers.

Hope that helps,

Laurie

Good info Laurie, as usual.

I just found this thread. Better late than never, right? You all put such good information on here. Thank you.