I live in zone 6b and struggle each fall with exactly how to winterize my iris beds, and when. For those of you in zone 6b or colder, what tasks do you perform in your iris beds each fall, and when? Thanks in advance for your replies.

I am south of you, but hopefully someone will chime in soon to help you!

Hippie, I just try to have all of the dead foliage removed and taken away before winter sets in. I also "like" to have them weeded and new pre emergent put down before winter to prevent some the weeds that seem to grow under the snow if we happen to have snow. I'm in zone 5, but we haven't had much snow yet this winter.

to the iris forum, hippie.

i'm on the west coast, and we don't have snow. once in a blue moon we do have a freeze. sorry, i can't help but, i'm sure others who are in your zone will chime in.😀

I am in Toronto and do nothing for irises, except as Tom mentioned try to remove all dead foliage. There are probably some that are more warm-loving than others, so check plant growing zones before you get anything subtropical. And the roots are partly above the ground even the temperature in Toronto is way below freezing in winter.

in late fall/early winter in zone 6b:
does anyone trim back the foliage?
does anyone place straw, leaves, or another material over the exposed rhizomes?
should soil be placed over the rhizomes?

even though I have grown irises successfully for many years, it is good to hear what other folks do. there is normally always a better way.

Lately, if leaves blow into the beds I leave them there over winter, but remove them as soon as the warmer weather returns in the spring. I've done this because for the last few years, we have not had snow cover here that lasts all winter, and this year we keep having weather that is in the 40's one day and the teens the next. I'm hoping that the leaves will help hold the temp of the soil at a constant. I've heard of some people who use pine needles to cover them over winter. Many people cut the foliage back in the fall, other's don't. I've heard that the leaves return nutrients to the rhizome when they die back, yet I don't think it really matters much. Cutting the foliage MAY get rid of some of the iris borers eggs if disposed of properly. Some people burn off their iris patches in the fall, but not everyone can do that, and if you have mixed beds, it's a bit hard to do. I tend to think that irises do well in spite of our interferences.

I trim foliage and spent leaves and remove any leaves from trees in the beds. I find that for me the cleaner the bed is the less chance for rot when everything thaws out. Rhizomes are hardy to very low temps so they can handle a cold winter, especially with consistent snow cover. If you feel the urge to put straw down, make sure to pick it up right away when things start to melt or you will have a soggy mess that invites soft rot.

tveguy3 said:Lately, if leaves blow into the beds I leave them there over winter, but remove them as soon as the warmer weather returns in the spring. I've done this because for the last few years, we have not had snow cover here that lasts all winter, and this year we keep having weather that is in the 40's one day and the teens the next. I'm hoping that the leaves will help hold the temp of the soil at a constant. I've heard of some people who use pine needles to cover them over winter. Many people cut the foliage back in the fall, other's don't. I've heard that the leaves return nutrients to the rhizome when they die back, yet I don't think it really matters much. Cutting the foliage MAY get rid of some of the iris borers eggs if disposed of properly. Some people burn off their iris patches in the fall, but not everyone can do that, and if you have mixed beds, it's a bit hard to do. I tend to think that irises do well in spite of our interferences.

thanks, I'm concerned about heaving and losing rhizomes over the winter. I lost a few last year, and am trying to prevent that from happening again, if possible.

Dachsylady86 said:I trim foliage and spent leaves and remove any leaves from trees in the beds. I find that for me the cleaner the bed is the less chance for rot when everything thaws out. Rhizomes are hardy to very low temps so they can handle a cold winter, especially with consistent snow cover. If you feel the urge to put straw down, make sure to pick it up right away when things start to melt or you will have a soggy mess that invites soft rot.

We rarely have snow cover anymore, and last winter we had zero snow. I have always trimmed the foliage back, picked off the dead stuff, and then covered the rhizomes with straw and/or shredded leaves. I then remove it in very early spring. It's just been what I do, but always wanting to do better.

A good brick on top of the rhizome is good against heaving and so is a landscape fabric staple if you have it.

I am in Zone 6b and I do most all of the things that have already been mentioned. I put bricks or landscape pins on all new plantings and some old ones if they look like they might heave again. I use pine straw wherever I can and leave the leaves on the plants even though I am tempted to cut them back. I do that in the spring to remove the leaf spot that has remained from all of this rain we are having. When warmer temps return in the spring and it does not look like we will have more frost (always wrong on that count) I remove all of the leaves that have accumulated and dead iris leaves too.
I have tried to keep the late winter weeds pulled although that is a real chore and the bitter cress is relentless!!! I put my potted irises either in a cold garage or under the deck near the brick house.
I am constantly learning new tricks on here and at iris society meetings.

A light cover of pine needles can be helpful with a new planting. Remove in spring.

Welcome to the iris forums, Hippie!

This thread is helpful to me too....I need to clean up those iris leaves!...and also staple them securely to the ground as our ravaging chickens have uprooted quite a lot of mine. Good luck with your ventures!

The only time I've had issues with heaving is when I plant too late in the season, and they don't have enough time to send down enough roots to anchor themselves.

Welcome to the forum, Hippie!

I didn't have much time this fall to clean off my beds, and we had snow after Thanksgiving. I often take advantage of warm winter days to catch-up. For example, two weekends ago, the temp reached 50 degrees F here in zone 5b, so I spend time removing wet iris leaves and wet tree leaves from the beds.

Like Tom, I don't have many rhizomes that heave unless I plant too late. I have more issues with rhizomes sinking. I think Arlyn once described the soil here as "fluffy". The anchor roots certainly hold, and when the soil heaves, the rhizomes sink.

Thanks for starting the discussion! It's interesting to hear other's strategies and rituals.

…...As to "fall care",...I think it kinda' depends on "when you want to do the work" . Most chores can be done, in the fall, OR the early spring......clean-up is the main one. I have found I have the best luck (and the most time!) in the fall. I cut back the foliage on all the irises, to about 4 inches (it's going to die, and become a slimey mess, before spring, anyway) in mid , to late, November, and rake all of it out of the beds, going over everything with the leaf-blower, after that. All the iris foliage (and the tree leaves that have already blown into the beds) gets hauled off to the dump.....I don't compost that, because of the chance of spreading disease. After every thing is "clean", I go over the beds with a "weed burner", burning / singeing anything that's left (I give all the iris clumps a good 'dose" of flame, but move along, pretty quickly, so the rhizomes don't really get very warm)…..IMHO, the flames get rid of a lot of the fungal spores, and insect eggs....making for less leaf spot and borer trouble, during the next season. After the "great burn-off', I add any lime, that I might need, spray any persistant clumps of grass, or perennial weeds that may be in the beds.....and head south , for the winter ! ! The only thing I wouldn't do in the fall, is add fertilizer....it will just 'leach away' before the plants get "active enough" to utilize it, in the spring, when growth starts.
When I get home, In March I clean up any tree leaves that have blown into the beds (with the fans all "cut back", most tree leaves just blow right through the beds, without "sticking", and a quick "once-over" with the leaf blower takes care of those that DID stick in there !), add any fertilizer that's needed, apply my first "dose" of pre-emerge weed control, and the first dose of borer control., and correct any that aren't at the correct planting depth....either scratching away soil from those that look "too deep", or adding some to those that aren't "deep enough". As was stated, unless they are planted "too late" to set a good root system, heaving isn't usually a problem, for me.....if I am worried about it, a brick on top, or some "landscape staples" will help hold them down, and, as was stated, a mulch of pine straw (or anything that won't "pack down" can be applied over the rhizomes (best done late in the winter after the frost is in the ground, and removed in the early spring, before new growth starts).
That said.....you can ALWAYS find things to do in the garden, and you NEVER have enough time to do all that you would like too, so, don't knock yourself out worrying about it....irises are pretty 'forgiving" when it comes to winter care, and if you're taking a "winter stroll" through the beds , on the 'nice days", any heaving', or large accumulations of tree leaves can be dealt with, then !

UndyingLight said:Welcome to the iris forums, Hippie!

This thread is helpful to me too....I need to clean up those iris leaves!...and also staple them securely to the ground as our ravaging chickens have uprooted quite a lot of mine. Good luck with your ventures!

You obviously haven't heard of my world famous weeding chickens, guess it's been a while since the topic came up. It is simple to create weeding chickens, one only needs to incubate your own eggs, and do a pre-natal training process with them while incubating the eggs. When they hatch, they are all set, once grown up they will do your weeding for you. To train the eggs, one needs a tape player that will teach them what they should eat, where to scratch, which insects to eat, which to leave alone etc. You must also teach them that chicken soup is made of chickens who uproot irises!

Something to keep in mind when we are ready to get our chickens!

Welcome Hippie!

Tom forgot to include a photo of one of his chickens.