Hardiness Zone: 7a
Leah from Shelbyville, TN
Mowing them is fine after they are done blooming, but it is always best to wait until late in the season so the foliage has ample time to store nutrients for next year's bloom. Tell your hubby to hold off or even skip it this year and see if they come back strong next year. If not, then you need to look at other possible causes.
When irises fail to bloom it is usually due to nutrient deficiencies, inappropriate watering, incorrect planting depth, or overcrowding. In your case, you mentioned that your irises bloomed well for the first 2-3 years, but have failed to come back strong since. Have you divided them in the past few years? In not, I suspect they are in need of some breathing room by now. After a period of 2-3 years, irises start to grow into clumps and become overcrowded. They won't bloom well again until you give them a bit of breathing room.
Another cause to consider is whether a few years of mowing over them have buried the rhizomes under a bit of lawn mower mulch. If these are bearded irises, they should be sitting in the soil so the tops of the rhizomes are at or only very slightly below the soil's surface. If planted too deeply, you will see foliage, but no flowers.
Ellen
Mowing them should not damage them at all. Iris's are hardy. You may need to uncover the tubers however and pull some of them apart.
I am not a gardener but, I have Iris as they almost grow wild. The tubers seem to work there way out of the soil, so just brush the soil away. Look at the top bunch of tubers and see if they look eaten or mushy. Bugs will often times feed on the top bunch. Pull those off lightly. Then just cover the others up.
If you are mowing down the tops, you are not allowing the tubers to "feed" and build up energy for the following year. The leaves are there to process the water and sun and feed the tuber, and if you cut them off, there is no food going in and eventually the tuber will just die back.
We had iris that didn't bloom (maybe one or two would) but this was because the iris bulbs or tubers were VERY over crowded & needed to be thinned out... Are yours over crowded?
I have tons of iris and I actually use the weedeater to take them down in the summer. Allow the leaves to stay a while after they bloom so they will get good "energy" to the tubers. The most improtant part of good blooming iris is that the tubers are exposed, I also live in TN so our weather is not so harsh. I always make sure that they are not too tight ( I actually just pull some out like carrots) then make sure that the tubers are not covered.
I love iris !!
You may have them planted too deep.
Just barely put the risome in the soil......if there are those little "leg-like" pieces sticking out, put soil over those too. Leave the largest part of the risome just sitting on top of the soil.
They need those "green" tops ( leaves) to provide food for the risome after the bloom.This provides the food for next years blooms. By cutting those off, you won't get blooms next year.
Most folks cut the tall green leaves into a ^ shape, a Fan shape, or inverted V , in late July or August. Just use plain ole scissors to trim the leaves.This tidies up your flower bed. Yet there is enough green tops to provide the food necessary for next years blooms.
After enjoying the blooms, cut off the tall stems that the blooms were on...try not to scalp it...leave it as long as the leaves are tall.
Try not to allow the iris to send up a large round "pod" looking thing on the stem following the blooming. This is called "going to seed." And it will take a lot of the nutrients from the mother plant.
When it happened to us, it was Iris Borers - a white grub that eats and destroys everything. We had to dig them up, destroy the borers we could find, sprinkle campfire ashes into the dirt before replanting them.
I loosely braid my iris leaves and allow them to remain until they've done their job of storing energy for next season's blooms. I tie the ends off with strips made from leaf material. I do a few each day so it's not like I'm out there braiding leaves all day.
Irisis are like tulips and daffodils and most bulb or tubular plants. They need the leaves to feed off of for next year's blooms. After they are done blooming just leave them alone for a month or 2 till they start looking dry,then cut them down with scissors to about 3 inches above the ground and they will do fine the next year. Also about every 3-4 years they should be seperated and thinned out. Good luck
Just a note: Iris is toxic, so be careful what animals you feed those grass clippings to.
My Dad ALWAYS mowed down the Irises. We would have to separate them every now and then. Then they wouldn't bloom too much the first year, but the second year they'd be fine. 45 years later I have some of those Irises from my parents house planted in my yard. Can't kill them!
Hardiness Zone: 4a
Judi from Elgin, Oregon
Your assessment of the situation is probably right on the money. Irises grow in clumps. As they grow, they start to get crowded and their productivity declines. Dividing them every 2-3 years will easily solve this problem.
To divide your irises in the fall, cut the fans (leaves) back to 3 to 4 inches in length and use a sharp spade or shovel to separate them from each other so you can lift them out of the ground. When replanting, make sure you pick a sunny spot and that you plant the rhizomes so that the tops are exposed at the surface of the soil, or only slightly covered with soil. Water them in well.
Other factors that can affect how well your irises flower include the following:
Ellen
Hi,
Iris do not like to be crowded, so dividing them is probably a good idea (not sure of timing for this myself). I do know that while the roots need to be deep, the rhizome needs to be near the surface. Below is a link that you might find useful for growing/planting iris.
Good luck!
Joyce
What do I feed Irises? I've had these irises since we bought the house in 2002. I've divided them and replanted them in many locations. I was told to feed them Bone Meal in the fall (something I haven't done yet). Is this good for them and if so where do I get the bone meal? The color has faded over the years in the leaves. I think that's due to improper feeding, am I correct? I also want to re-do the flower bed where they are now. Can I dig them up now, fix the bed and replant them now?
Hardiness Zone: 8b
By Marlene from Tonopah, NV
I have bearded iris in a raised bed. The last two years, I find as the iris bud comes up nice and tall, something is clipping the stem, snapping it off with a nice clean cut. I find the blossom on the ground. Are birds doing this? How can I prevent this from happening. Last year, I lost about half my blossoms this way.
Hardiness Zone: 5a
By Gary from Syracuse, NY
Should the ever-blooming iris be cut back at the same time as regular iris? If not, when should they be cut back?
Hardiness Zone: 7a
By Cathy from Williamsburg, VA
As you may know I'm starting a new iris bed in "The Path Garden". I saved this picture a few years ago and can't remember where I got it. Does anyone have this iris or know the name? I would love to have it added to the garden for next year. Thanks for any help ThriftyFun's family can provide.
By Vi Johnson from Moorpark, CA
While the others are still not ready on that plant can I cut back just the top bloom and give it away?
By Jeff
My iris last bloomed 6 mo. ago. I have been watering it and 2 weeks ago it started to grow tubers. 4 at the sides of the leaf base and one going straight up. Which of these if any might produce a bloom?
Please help, this was a trash can rescue last fall.
By Bob from Toledo, OH
This iris has done nothing for 6 months. It has started to grow 5 shoots a couple of weeks ago. 3 out to the sides and one is growing up. They are about 1/4 inch around and have a pointed tip.
By Bob g. from Toledo, OH
Any suggestions on best way to grow irises and when, or if, you should cut them?