Allowed iris in kitchen

Do you have a rule, "Keep the garden outdoors, please?" Then maybe you already know it can be a big mistake to allow exceptions.

Better to install a sink and counter in the garage, or put plumbing into a back room. It's worth the cost to keep the gardener out of the kitchen.

What to do with an iris in Winter

As a prime example, Steven had planned to cook a chili the other night but came home to find the kitchen overtaken by iris projects:

• The no-freeze iris slices

• Firm, fat divisions

Pests in the refrigerator?!

• (...and extra info because we know you'll ask: Iris planting instruction.)

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No freeze iris

"People asked about the super cold we had," Janet said. "I'd emailed back about how the snow that came first was a great insulator, that most perennial crowns had not even experienced freezing temperatures. Then suddenly I remembered that I forgot about all the iris clumps we had sitting in the garage. They were above ground, bare root or nearly so. Little or no soil insulation there. I had to see if they were still viable."

"And are they?"

"Looks like. See, here's a slice of one of the rhizomes. Firm and white, it didn't freeze." 

Below: No matter how hardy the plant, to freeze is to die. Super hardy species, including zone 3 (-40°F) bearded iris (Iris germanica) have ways to keep ice from forming within their cells. Internal anti-freeze is usually involved yet soil's insulating qualities play a big part in keeping roots alive.

Soil often remains right around freezing (32F) even when the air just above is much colder. So when these bare root iris clumps spent some -17°F time in our unheated garage, we sliced a few of the rhizomes to determine their fate. We were pleasantly surprised to find firm, white, tissue (inset photo). They didn't freeze so they're still alive.

 

 

To make that nice division, we start by breaking up the iris clump and identifying some husky possibilities. Every piece of the iris rhizome will grow but we almost always have 'way more than we need when dividing so we usually discard the tiniest as well as and the oldest rhizomes. (Old pieces usually don't even have a leafy shoot.)

To make that nice division, we start by breaking up the iris clump and identifying some husky possibilities. Every piece of the iris rhizome will grow but we almost always have 'way more than we need when dividing so we usually discard the tiniest as well as and the oldest rhizomes. (Old pieces usually don't even have a leafy shoot.)

In search of the best iris division

"Okay," Steven said, "so you wanted to see if they froze, I get that. But what's all this mess?"

"Well, there was no sense handling them without cleaning them up and dividing them so they're ready to go. I'll send a bunch of them to Diane, now. Get them off our hands. It's nearly spring there in California, Diane can even put them in the ground now..."

Below:   The ideal iris division is a husky "Y":
Husky, so the plant that grows from that rhizome will bloom right away -- the growing point on each arm of the Y has enough substance to produce a flowering stalk.
We look for a "Y" because that plant will be more stable, less likely to fall over in bloom. Each arm of the Y develops its own wide root system and like opposing guy wires on a tall antenna or the outrigger on a Polynesian canoe, each will counterbalance the other.

 

 

Above:  These divisions made in winter will bloom shortly after being returned to the ground. That may not allow the plant enough time to anchor itself with new roots, so they may require staking.

Above: These divisions made in winter will bloom shortly after being returned to the ground. That may not allow the plant enough time to anchor itself with new roots, so they may require staking.

Here, we're using a bent section of clothes hanger across the "Y."

Here, we're using a bent section of clothes hanger across the "Y."

To avoid the need to stake, follow custom: Divide iris in summer and put them back into the ground by fall so they have plenty of time to grow roots before producing that next flowering stem.

How to plant this iris? Choose a sunny spot with sandy soil that's never soggy. Scrape out a depression just deep enough that the rhizome will be barely covered or even have its "back" exposed. Set the rhizome* in that depression with the root-y surface down. Firm the soil around or over it. That's it.

If this rhizome had been freshly dug and still had live white roots, we'd have you dig trenches alongside the depression you make for the rhizome. Spread the roots into those trenches so they extend outward and angle down.

 

Rhizome: What you see here are often called roots or bulbs but technically they are stems that grow along the ground and develop roots from the lower side, leaves and flowering stalks from the upper surface. That kind of stem is called a rhizome.

Then we look closer, and use our fingers to test the rhizome's firmness. If there are soft spots we may yet discard the piece or at least have more to do. Rotted portions like the peeled bit you can see below are dead, probably destroyed by iris soft rot. That's a bacterial disease that lurks in the soil. (It could as well have been called "stink rot" for its strong odor.)

Then we look closer, and use our fingers to test the rhizome's firmness. If there are soft spots we may yet discard the piece or at least have more to do. Rotted portions like the peeled bit you can see below are dead, probably destroyed by iris soft rot. That's a bacterial disease that lurks in the soil. (It could as well have been called "stink rot" for its strong odor.)

Soft rot isn't really virulent but the dead material is infectious. Even the best grown iris is likely to suffer wounds that are the bacteria's doorway. Wounds come from cutting tools, weeders, shovels and above all else, from iris borers. So we'll cut out all bad portions to reduce the sources of new infection.

 

 

Now we're cutting. We're not done, just stopped to show you that it's just like cutting the bad spots out of a potato or an apple. You'll be able to tell what's good and not.

Now we're cutting. We're not done, just stopped to show you that it's just like cutting the bad spots out of a potato or an apple. You'll be able to tell what's good and not.

Here's what's left of that piece after the cutting's done.

Here's what's left of that piece after the cutting's done.

We've also rinsed and then soaked it for two minutes in water with a bit of bleach added, because where disease is likely, disinfecting is a good idea.

We've also rinsed and then soaked it for two minutes in water with a bit of bleach added, because where disease is likely, disinfecting is a good idea.

"See, Steven? It's not really so different than cleaning vegetables for dinner!"

"Except eating iris can kill you!"

"Well, yeah, there is that."

"And all that crud over there on the table where you broke the clumps apart!"

"Okay, okay, I'll start cleaning up. As soon as I look into these insects..."

 

Pesty insect issues

What insects are those? We   don't know, yet. They were   revealed when we peeled the   skin of the moist, rotted   section of one of the rhizomes.   Are they eggs? We don't think   so; probably early-instar*   larvae. Maybe they're   springtails, which are akin to   but are not insects. Or maybe   they are something more   sinister, an iris problem biding   its time until spring.

What insects are those? We don't know, yet. They were revealed when we peeled the skin of the moist, rotted section of one of the rhizomes. Are they eggs? We don't think so; probably early-instar* larvae. Maybe they're springtails, which are akin to but are not insects. Or maybe they are something more sinister, an iris problem biding its time until spring.

*Instar: A stage of
  development in an insect's life.
  This and other nifty words are
  explored in our
  Scrabbling department.

They are probably not iris borers, which spend the winter as eggs on foliage and other exposed surfaces. It will be March or April before iris borer eggs eclose (the insect version of hatching from an egg).

These critters we found, already 1/8 inch long, look more like they've been growing for a bit. Perhaps they've even finished early growth, are pupating and will emerge as an adult as different in appearance as moth from cocoon.

 

These critters we found, already 1/8 inch long, look more like they've been growing for a bit. Perhaps they've even finished early growth, are pupating and will emerge as an adult as different in appearance as moth from cocoon.

These critters we found, already 1/8 inch long, look more like they've been growing for a bit. Perhaps they've even finished early growth, are pupating and will emerge as an adult as different in appearance as moth from cocoon.

What next?

"I put them in the 'fridge to keep them cold
and let them have the winter to develop into something we might identify."

"They're in the refrigerator?! There's like a
whole drawer full of plant problems already in
there. You said you'd quit."

"But look at them, Steven. We haven't seen
this before..."

 

 

Your Iris borer connection

So now that you've seen what soft rot does to iris roots you want to know more about the iris borer? Good, because keeping that insect in check is the best way to reduce or even eliminate soft rot from your irises.

What's Coming Up 42 (Yet to be posted  -- you can Sponsor that!)
            • Divide in July to control. Never had this trouble? You will!

What's Coming Up 151. Click to open its page and download the pdf.
            • What you'll see and do in July.

What's Coming Up 157. Click to open its page and download the pdf
            • The iris borer moth

Growing Concerns 59: Click to read
            • The borer's life cycle and weak points

Growing Concerns 530: Click to read
            • Why pesticide is not the best control