Lasagna Bed for Irises

I would like to re-do a couple of small iris beds and was wondering if creating a lasagna bed would help. I would layer it first in newspaper, then compost, then .....what?..... to make it stop compacting down so easily. Woud a layer of sand help? It's got a good bit of clay in it, about 50% or so. I'm just so tired of my irises rotting from all the water the soil holds.

I have been slowly digging up my iris in the low portion of my sloping lot and building raised spots for them. I'm just adding dirt & mixing it with my wonderful native clay (yuuch!). I'm replanting my iris 2 inches or so above all the rest of my perennials. It's easier to keep the mulch at a distance from the ryhsomes and the raised areas don't hold the water like the depressions do.

I lke the lasagna idea but layers are going to compress eventually. Instead,
raise the beds so they are taller than the area surrounding them. You can do this by taking treated boards and making a rectangular bed. The soil should be about 4"taller than the area ouside the boards. This way even if it rains constantly, water will drain away from the rhizomes. Keep those rhizomes nice and high. You want the roots in the ground and the rhizomes 1/2 way out of the ground. Adding sand sounds like a good idea but I don't think I would make a layer...dig it in.. A lot of hardware stores carry good-looking concrete retaining wall bricks. I have salvaged wood from old fence posts...anything to be able to make a raised bed. There is a solution for any budget. Just get those rhizomes up high. Good luck!

What a great idea. I'm thinking of those interlocking "stones" at HD. A double row of those with some great sand and soil should be great. Thanks so much!

Those interlocking stones at HD are really attractive. I said 4" higher....but of course the higher you go, the better. I lost a lot of rhizomes many years ago with our rainy winters until I moved the irises to a hill behind my house. Some I lost were very rare, a tragic lesson in standing water and rhizomes.
Have fun "building" your garden!
M

Oye - I spent Sunday digging and dividing all my irises - I must have 200 or more rhizomes now to replant. I'm going to do the raised bed thing - easier and turns out nice lookin' too! Post pics Pins when you get done and I'll do the same! (Oh - my back still hurts!)

M :-)

Nothing that I have added to my clay soil has lasted all that long and made a permanent improvement. I think your best bet for improving drainage would be the raised beds, and rather than sand, I think pea gravel (stuff about the size of aquarium stones) would be better. I use that for my lavender and cactus.

I've never heard of using pea gravel. It sounds like it might work. It doesn't get compacted with the clay?

Kelli...
Do you dig the pea gravel in or put down a layer before heaping the clay on top?

I dig it in with the dirt. I don't know for sure if it doesn't get compacted, as I've never dug up an area where I had previously put gravel, but I don't think it would.

Kelli,
That sounds like a great idea, thank you so much!

My clay soil is sooo much fun. NOT> Hard like cement when it is dry and like taffy with this rain. Oh well wanda, stop complaining and keep digging before DH comes home & finds more grass gone....

I have planted my iris in pots - in nature's helper. After reading this, maybe that wasn't such a good idea! We are blessed here to have good forest soils, so maybe I should replant? Raised beds I can do (or a good slope). And I'm hearing that mulch isn't good next to them - right?

Thanks, y'all.

I mulch all my beds, but keep it a few inches away from the iris clumps. It holds moisture & can rot your ryizomes. You need iris uncovered & dry.

Hmmmm I'm thinking I might have messed up making my iris bed way too rich. AND I think I also "planted" them too deep, instead of just covering the roots.

Do you think maybe that's why they didn't bloom for me? They all look very healthy, and since they were very dry rhizomes when I got them, I was very proud of that.

Ok so to get ready for fall, am I right that I need to go out there and either MOVE them to a drier, less rich soil, and/or lift them out of that soil a bit, then mulching around them for winter?

Or would it be ok to just move them to another bed entirely, using that rich soil for something else, like maybe herbs (?)? Not grown enough herbs successfully to know if they need rich soil or not.

I'm SO glad I found this thread. Such great posts here! GREAT info!
~ Carole

I can see the top of all my iris roots. And the soil is nasty clay in most places.
Abuse the iris--plant them more shallow with lots of drainage & sun. Save the good dirt for something more delicate.

Oh I'm so glad I asked! See when I had irises at my old house, I didn't even know what they were until they'd bloomed! I never did a THING to care for them because I wasn't even gardening yet. My MIL told me they seem to thrive on neglect.

Guess I've been "pampering" mine too much.

Thanks!
~ Carole

I've seen the darn things bloom after spending an Iowa winter in a wheelbarrow outside! Just keep the weeds down & other plants away so they get lots of sun & air flow.

Like Wanda, I garden in heavy, concrete clay that consumes every bit of organic matter I till into it with disheartening speed. Over the years, I have lost hundreds of iris cultivars to rot in this stuff in spite of the fact that it actually does drain quite well. I finally determined that it wasn't the moisture-retentive qualities of clay that was rotting my irises as much as it was the concrete consistency that was suffocating them to death. Courtesy of a dense local deer population, our large 4-legged family, and my own enormous feet, the clay in the iris beds was being constantly compacted around the rhizomes.

Last summer when I renovated 4 of the 6 iris beds, I did something different. After amending heavily with anything and everything I could get my hands on (LOTS of very well aged horse manure, alfalfa meal, perlite, sphagnum peat, gypsum, potash, superphosphate, and lime), I tilled and raked my beds into a series of windrows and gutters. The windrows were raised 4-6", and I planted the irises on top of them. With all the amendments, the soil in the windrows was light and friable. My irises could finally BREATHE! After having lost about 150 cvs over each of the preceding two winters, I lost less than a dozen this last winter with the new windrow/gutter arrangement.

The windrows serve several important functions in my iris beds that I believe account for the vast improvement in my iris survival rate:

1) Improves drainage
2) Provides fertile, uncompacted soil that allows rzs to breathe and increase
3) Directs foot/hoof/paw traffic down the gutters rather than on top of the windrows

Since this is a new planting arrangement for me, I am already seeing the need to tweak my technique a bit. Because I couldn't decide where to build a new bed, I had to cram as many windrows into the existing beds as possible, and that made both the windrows and gutters too narrow. When I do build a new bed, I'll space things out to widen both elements. I'll also try to make the windrows taller since they have lost at least half their height over this first year. All in all, though, I'm extremely pleased with the results so far.

Give them excellent drainage and a light soil, and you can't go wrong!

Laurie