Question for the Bearded Iris lovers

Can you grow Bearded Iris on top of wood mulch and/or around it?

Thanks!

Marilyn

IMHO - No. The wood mulch will absorb and retain water, which in turn promotes rot.

Grannymarsh,

Thanks for answering.

If I were to plant some in a mixed bed, I'd have to remove some wood mulch for the B. Irises?

Marilyn

Yup. You need to keep it away from the rhizomes. Not only will it attract long lasting dampnesss, it provides an inviting environment for bugs.

Wouldn't it get muddy (after it rained) around the Irises? How do you deal with that Grannymarsh? What about if you put pea gravel next to and around the plant (but, not on top)?

It does get muddy around unmulched iris after a rain. That really doesn't hurt anything. I use a shredded wood mulch on my tomatoes, eggplants, daylilies and many other things, but the rhizome part of the iris likes to be exposed enough ( maybe 1/2 way) to get a little sun. I have some under gravel, but that is due to previous owners. I am removing it as fast as I can. The iris seem to tolerate gravel better than organic mulch, but they still don't like it.

Pajaritomt,

Heck, I'm gardening on a sand dune (think Lake Superior) so mud is the least of my problems. No measurable rain in two months is my current whine.
Are you working with clay or what?
I have grown TB's in rocky soil.

I have horrible KY clay that I have to amend and lately, we too haven't had much rainfall this season and it's been a very unusually hot Summer.

One of my most successful Iris beds was out by the road. In Michigan, the road shoulders are often topped with crushed limestone and of course, this rock tended to find it's way into that flower bed. When tested, this soil was flat nuetral and the Iris loved it. Well drained, full sun and a bit on the dry side.

How can I tell?

I have irises that have rotted from too much moisture which is what happens when they are mulched or buried to deeply and there is a lot of water present. I have a lot of gravel in my yard thanks to the previous owners. I am little by little removing it. I dig a hole, plant something, perhaps an iris, then fill it in. Frequently the gravel washes in from the rest of the still graveled flower bed. The irises with gravel on top don't grow as well as the ones that don't have gravel on top. None have rotted yet, because gravel holds very little water, but they just don't get the sun on the rhizome which they seem to really like.

You can improve drainage for your bearded irises in a mixed bed by pushing the mulch away, then creating a mound of dirt onto which you plant the iris rhizome. The dirt mound acts as a mini-raised bed, allowing moisture to quickly drain away from the rhizome itself so that it doesn't sit in muddy clay and rot.

Laurie

Sorry But I disagree that mulch leads to rot.
The one bearded irises that DEMANDS little moisture are Arils
this is my aril bed.
pH can affect the breakout and control of rot. This bed and most of my bearded beds have tons of lime in it. reason my pH naturally is 6.1 great for Japanese and beardless horrible for bearded and I had a horrible rot problem especially when I saw all that nice shredded oak leaves and used them for mulch.
Dr. Spoon gave a talk on pH and the health of the iris and I went home and loaded my beds with lime rot was decreased to less that 3% compared to nearly 30% the year before. Unfortunately I failed to put the same amount in a new bed and fought rot all spring. No other beds except certain irises which are known rotters developed this problem.
I have since corrected this problem.
As the extra lime does not seem to affect the daylilies I am very liberal with it.
HOWEVER! I still do not cover rhizomes.
I hope this helps
best thing is get a pH sample of your soil and lime it if less than 7
:)
Anita

I gropw all my iris in mixed beds on raised mounds. I mulch around all the other plants, but the german bearded iris stay high and dry. Mostly clay here too--iris LOVE it once they are rooted properly.

Anita,
Thanks for the info about ph. I don't have much rot, but in the past I have always blamed it on the water. It could however be the ph since my soil is basically neutral, but I add quite a bit of organic matter to it before I plant. I may have to seek out some lime to see if that helps in the places where I have found rot.
I am thinking the water has to have something to do with the rot because I never had any until I put in my drip irrigation system.

Check pH of your water
Erwinia which is the bacterial soft rot may not be your problem then and may be due to other problems.
I am very wet at times here such as this week we have been in the 60oF range VERY unusual for August which is usually dry and in the High 90s
well those temp will return tomarrow and a large jump and/or fall in temperture can cause severe damage to the rhizomes which is an entry for Erwinia which is a normal soil bacteria.

I wish you good luck
PS try listerine 50:50 with water for spot treatments. I used it this spring on the rotters and it saved about 80%
:)
A

I will check the ph of my water and love the idea of listerine for rot. The places where I found the rot were a little low and very rich in organic matter. They stayed damp longer than other places in my garden. I dug out one clump, cleaned it, soaked it in clorox and moved it to a dryer place where it is growing very well. The second place, I haven't tackled yet. When I did test my soil ph is was neutral, but I add a lot of compost which probably makes it slightly acidic at least for a while. My hydrangea blooms blue which is a sure sign of acidity -- at least that's what I hear.

I'm going to chime in here. I mulch around my irises but only enough to smatter the mulch over the dirt. I do not have much problem with rot unless a clump is over grown and needs divided. I happen to not use hardwood mulch. I use "pine fines". I compare that with a section of the bed where no mulch has been used for 3 years (just never got around to mulching it -- so I decided to watch the progress). The only difference I've seen between the two section of the bed is the weed content! Less mulch = more weeds which help to ruin the fun of irising in that area. More mulch = less weeds and it's more enjoyable (evening weeding).

I'm not an expert yet. It just works for me. :)

It will be interesting to see what 20 or so inches of rain in 2 or 3 weeks will do to my irises. They are planted in mounded rows and I have been keeping them well weeded so far. They are doing beautifully this summer - perfect foliage tall and sturdy. These are the survivors from last years Borer War, and I planted them in new ground that happened to have had a load of lime dumped on it. I was afraid that the lime might be bad for them, but I planted there anyways...Glad to hear they like it.

Surprising how strong iris can be. I need to clean out some of my clumps. Lots of root loss from the April freeze & spring rains. I lost some historic clumps--wierd.

Wandasflowers,
As a recipient of a number of historic iris from you my first year on this forum, I would be happy to send you a piece of each one you sent me if you no longer have them. I bet a lot of the others who have received your iris would do the same. Let us know what you are missing. If you ever sent it out, I bet you could get it back.
Betty

I Also have some historics that you are more than welcome to

Thank you for your generous offers, but I have already been able to replace most of them. I need to get into the beds these next two nights and dig out dried iris roots. Been distracted too much of the summer.

OMG! To mulch or not to mulch. Call me having the luck of a fool!
I planted bearded irises 4 years ago, the bed's clayey, but amended and through the years, had applied mulch over them. So far, each year they produced beautiful blooms and multiply like crazy.
Pulled out some hedychiums, and about to transplant more irises in that bed. Was going to plant over those old mulch, of course after adding good soil. Looks like I'll be removing those mulch, and leave these irises unmulched.

I've never mulched anything:LOL: When I got into planting TB's I just sort of went by the beds of them that I had seen around. Most were bare earth with explosions of iris. When I finally got a PC and looked at the iris growers fields online I noticed that most are planted in vast fields of bare earth so I figured out that I accidently did something right:LOL:

My front bed was mostly clay when I first began digging in it 12-14 yrs ago. I pulled out huge hunks of red clay and have added at least 20-30 cu. ft. of potting/garden soil, peat, compost and soil conditioner to that 6 ft x 3 ft bed over the years:LOL: It's like a black hole sucking down soil enhancements! I removed all of my noid iris and planted all new in Dec. (I slacked off and did a flurry of late late planting during one freak weather week in Dec with 80 degree temp!) and I have a few flower stalks appearing anyway:)

Well, after I posted above, we went to our favorite small nursery and lo and behold...she had a huge bed of big, beautiful, NOID, purple irises and guess what?? She mulched them with pine straws. Perhaps they benefit from the extra acid from the pine.
Me--I like the idea of not mulching! ^_^

Does she keep them mulched all summer or just for the winter?

I find that when I accidentally cover an iris rhizome with anything it doesn't grow very well, slowly loses leaves and possibly even dies if I don't catch the problem in time. That said, I understand that in colder climates people do cover their iris rhizomes. I am not very clear on the details, though.

It's all year round, she has them mulched, Wanda.
I've been observing irises grown around here. This is pine country, and I notice majority of them were mulched, with pine straws and have no ill effects.
Mine were mulched with commercial pine barks, and the blooms are miniscule compared to theirs. Perhaps the pine straws are not as dense as the barks?Gonna find out next what they've been feeding theirs with!

We put a pine needle mulch on the iris during the winter to help prevent heaving caused by the freeze & thaw problem in the winter. It is off in April. Iris rhizomes are food storing stems and if there is mulch on bearded irises will lead to rot. If you are trying to keep weeds down with a mulch be sure that is a space away from the rhizomes, which gives a smaller area to keep weeded. Welcome back home pajaritomt I think youwere home earlier from convention than we were.

Thanks for the welcome home, IrisMa, and the same to you. It was great to meet you and your DH. I got home on Sunday afternoon. In fact, I live a whole lot closer to Austin than you do. No wonder I got home sooner!
I sometimes get a pine needle mulch unintentionally because I have a lot of pine trees in my yard. I do try to pull them off in the spring, but more fall constantly. It doesn't seem to bother the irises. II wonder if they aren't a more "airy" mulch than bark, etc. By that I mean that I wonder if pine needles don't permit more air circulation than other kinds of mulch -- explaining their failure to kill everything.
Heaving is rarely a problem here -- perhaps because our soil is so dry.
Hope you are recovered from the stress of the trip! I am almost recovered.

Aiis true & good. If the ground stays frozen in the winter haeaving is not a problem. Alternating freeze & thaw is. No pumilas in bloom as yet. DH is pleased--he was afraid that we would miss them. I'm also pleased as I have plans for the pollen. The LA are not usually seen at conventions so they were a treat.

How about some pictures from the conference, and of those DGers that attended? A whole thread for that would be nice.

Will do. I already posted a couple of clump shots from the convention in the clump shot thread and have added photos to plant files. But will begin a 2008 Convention thread here and hopefully, the other attendees will add to it.

I'm new need a answer.

What is your question, ge1836?

I started a new thread that includes pics of my chewed off new iris.
Hope you can find it. Gives more info.

All of you are so helpful to us that are just getting started with iris. I would have killed them all (with mulch) had it not been for the pros here at DG. Thanks for all the info!
Becky