I don't think a "hill" is going to provide the sort of drainage you're looking for, esp. in clay soil. Anything 8-10' wide is going to hold water across the top unless you build it as a cone shape, and that would be difficult to maintain without rains causing erosion. You'd be better off simply planting your irises on top of raised windrows, maybe 2' wide X 6-9" tall. It won't matter how much snowfall you get; the raised windrows will drain very quickly as the snow melts.

I garden on solid clay here, and I add as much sand and organic amendments as I can get my hands on when I rework a bed: well aged manure, compost, leaf mold, alfalfa meal, topsoil, perlite, etc. The more organic material, the better. If I were you, and I could afford it, I'd buy good quality topsoil and use it exclusively for the raised windrows, leaving the clay as a base for the roots to grow down into. Clay won't bother the roots, but if you work it up and mix it into the soil around the rzs, it can cause compaction, suffocation, and rot.

I've never had to deal with moles, so can't help you there.

Good luck with your move!

Laurie

Heidi,
I think Laurie gave you very good advice. Much of my yard is heavy clay where the top soil was removed when the house was built. I planted many of my irises on a steep bank that was cut for the driveway, but even with sharp slope the clay soil on the bank retains a lot of water once it gets wet. During periods of drought the clay hardens so much that the water runs right off except where it erodes.

I've used products such as "Sofn' Soil". I think they are mostly gypsum. It does help to break up the clay, but I prefer to till in the more natural, organic materials that Laurie mentioned. I also tried adding sand, but it didn't seem to make that much difference in our clay. Last year I did have some top soil delivered, and that has seemed to help quite a bit. The ground in the beds where I worked in the new soil is still a lot more workable than in those that didn't get the new stuff. I'll be adding top soil to those beds this year.

We have a terrible mole problem here. I haven't found a good solution since I have 2 dogs and refuse to use baits. Years ago at a previous house wtih a much smaller yard my husband sat in a lawn chair and watched the mole tunnels for any sign of movement and was able to spear the moles with a pitchfork. That seemed awfully cruel to me, but it did work. He also flushed them out with a garden hose, but often that just caused a very soggy yard. At our last house we had a fantastic mouser. The moles just never got a few feet past the property line with her around. She proudly lined up and displayed her catches at our back door. I've thought about getting another outdoor cat here, but the foxes, raccoons and occasional coyotes I don't feel this is a safe property for an outdoor cat.
Shae

Thank You both so very much!

Laurie, I nearly emailed you with these questions as I know you also have good snow pack and have succeded with growing iris rather well. The ones I've bought from you have all done great and I'm hoping will do good when we move too.
I like your idea about the raised rows better than my hills. They sound MUCH simpler. I would have really been bummed to go through all that labor for the hills and not have it work.
We're hoping to be there by June 1st so I'll get started right away amending the soil so that when I come back in July to dig, their new beds will be ready.
I'm sad to think of us leaving here right at peak bloom. I wait all year to see it... But, that's the way it is.
I'm going to print out your post so that I wont forget anything. I know you're very experienced with all of this.
Thank You!

Shae, Thanks for the great advice on moles! I'm not above sitting outside with a gun if it comes down to choosing the moles or my iris. I'm not a wicked type of person but moles and other little rodents don't hold a very big place in my heart. I had no idea you could actually see where they were when they're digging. Also, I didn't know that cats could get to them. We have two really great mousers so we may not have much of a problem to worry about. I do NOT like poison as it gets so many non-target critters too. So we'll be avoiding that...
I'll try to get some top soil if I find that our soil is really hard clay. I'm not used to clay at all, so this will be a new endeavor for me. We have horses, goats and rabbits so getting good compost is easy, except for having to wait atleast a year before it's ready to use.
Anyway, Thanks a Ton!
Heidi

Hi Heidi,

It's good to hear from you. I've been wondering about you. The last time I talked to you, you mentioned a "life-changing event" and figured you must just be busy.

I've been reading up over the Winter and my books say to ammend clay with compost, coarse sand, peat moss, etc.

One book suggests "double digging". It's difficult to explain, but it's a simple process.

You dig a 1' deep trench the width of your bed setting the soil aside (in a wheel barrow/on a tarp or similar). You then turn the soil another 1' down in the trench and ammend it in place. Then dig a trench beside your first and place the soil from the second trench on top of the first trench. Ammend this soil on top of the first area then the 1' below in the new trench. You keep doing this until you reach the end of the bed. Ammend the soil you first removed and use it to fill the last trench.

It's much easier to describe with images. By doing this you can ammend your entire bed to a depth of 2'. It would require some hard labor, but the book says it's worth it and it might be easier than a man-made hill. It's really not so bad once you get into the swing of things. I hand turned every last part of my garden and it stretches across my entire yard now(then again I don't have alot of clay).

Hopefully that rambling will help.
Brock

Hi Brock
Sorry so late answering... We've been pretty busy and I thought everyone was done with this topic. :o)
We've been planning on moving for a few years now and have actually thought it was going to happen a couple of times but something always seemed to come up that held us here. Well, we're dern right serious this year and, God willing, we'll get er done! :o)
That's interresting about the double trenching. I may try it out and see how it works. I'll admit right now, though, that I have a TON of iris to move so the easier the better this year. Also, we'll be building our house so time is pretty restricted also. I'll be amending the soil all I can once I can find the time.
Truthfully, I'm extremely scared that my iris won't do very well up there. A lot of snow cover just scares me... Plus, not seeing many gardens in that area and being told that you can't grow anything but cold weather crops there. However, just about 4 miles down the road a guy has a peach orchard. So I just don't know what to expect. I keep thinking where there's a will there's a way... I guess we'll just have to wait and see.
I do know that I'm going to be fostering out some of my seedlings that I really like just incase iris don't do well up there.
Thanks for the info and it's nice to chat with you again!
heidi

Don't worry about the snowpack, other than to provide drainage for when it melts, by planting the iris on raised rows as Laurie suggested.

Snow is a great insulator. We are in the NY snowbelt, and average 120-180 inches per year. Currently we have about 2 feet waiting to melt in the next two weeks or so.

It's great for growing iris. Bearded do just fine. I've had very very few winter losses. Siberians and Japanese love it.

Something else you might consider using is the little spinning flowers to keep the moles and golphers away. It is my understanding that they do not like the noise or vibrations from them when they are spinning in the wind. So they go somewhere else to make their little nasty underground tunnels. I also read somewhere that Red Castor Bean plants will keep them away.

Good Luck with your irises and your move.
P.S. If you need a nice warm place to ship some of your seedlings to I'd be more than happy to grow a few for you. I live in the Piney Woods of East Texas where it gets nice and hot.

Happy Gardening, Marian
Our iris beds have already started blooming for the year. Of course I'm talking about the early ones right now. I planted over 500 named tall bearded last year. I hope to add a few more this fall. All of mine are grown for my own personal use.

I have a few daylilies too. (grin)

pollyny, THANK YOU!!!!!!!!! 10-15 feet of snow per year? That's hard for me to fathom, but I'd better start getting used to it as there's still atleast 4 feet of snow right now where we'll be moving. Don't get me wrong, I LOVE snow. I just want to help my iris as much as I can.
Thank you for your advice and experience. It helps me feel much better!

Marian, THANK YOU TOO!!!!
Depending on how many seedlings I have left over, I'd be happy to send you some. I have a few people really wanting some so I'm not sure how many I'll have left.

I have about 15 daylilies. I figured the daylilies and siberians that I have would do well up there. I may be investing in more. :o)