Never mind. Just remembered to do a drain test. That'll let me know no matter what I put in there.

If you add organic matter that will sit at the bottom of the trench, it will attract decomposers like pill bugs and sow bugs so be careful with that idea. If you feel like you need to improve the drainage, work those materials into the soil below the bottom of the trench and put a couple of inches of soil on top of them so there will be some distance between the seed potatoes and the organic matter. I have a lot of issues here in wet clay that is mulched in wet years. Pill bug and sow bug populations just exploded here in 2007 and 2009, which both had very wet periods in spring and early summer.

It is hard to say how wet is too wet for potatoes, but if you have soil that is too wet for them, you'll know it. They will tolerate moderately wet soil but not heavily waterlogged soil. I've always felt it is better to plant later if the soil is tremendously wet than to plant on time if your soil is really wet and if water stands in the trenches for more than a couple of hours. Your percolation test will show you how long it takes the water to percolate down into the soil below/around the trench and that should help you know if you can go ahead and plant now.

Because we have dense clay, we only plant potatoes in tall raised beds (they're about two feet tall) in wet years. That restricts how many potatoes I can plant in a very wet year, but it spares us the heartbreak (last endured in either 2010 or 2012) of having potatoes rot. That year, I planted on time into only moderately wet soil and wasn't real worried about it. Then, 6" of rain immediately fell within 2 weeks and most of my seed potatoes rotted. That's why we built the tall raised beds----so we don't have another year like that. We rarely have real wet years here, but when we do, the moisture usually falls from March through June and coincides with potato-growing time.

Remember that potatoes actually originated in the Andes Mountains where, presumably, they had good drainage. Potatoes prefer well-drained soil and getting a good crop in heavy, slow-draining clay can be a challenge, which is why raised beds often are recommended for gardeners with dense clay. Does it drive me crazy to build and fill a raised bed for the potatoes only then to have to dig deeply into it to plant them? Of course it does, but even when planted deeply in the raised bed, they still are above the grade level of the ground around them. Also, there's no point to planting them more deeply than 8-10". Research has found little to no benefit to planting more deeply. They will not put out tubers over longer stolons, for example, if you dug trenches 18" deep. It just doesn't work like that.

If worse comes to worse and you keep getting lots of rain, you can grow them in containers, hay bale beds, even in mounds raked up above the regular grade of the ground. At planting time, it is a leap of faith in a very wet spell----you have to really believe the rain will stop falling and the potatoes will grow and, if you don't, then plant them somewhere else. Or, you can hedge your bets and plant half your seed potatoes into very wet ground and the other half in containers or in mounds of soil raked up above grade level. You don't have to build fancy raised beds with stone or wood edgings....you just have to give them a way to stay above excessively wet ground. There's nothing worse than losing all your seed potatoes and all your dreamed-of potato harvest to persistent, heavy rainfall, but it occasionally happens.

We had a good crop last year. Started late and harvested a bit early. No need for me to fix something that ain't broke.

the wetter it is the shallower i plant then hill later

Bon, I understand that, but you have to remember that every year is not the same and that's the point I was trying to make. That's all. What works for a gardener with slow-draining clay in a dry year will not necessarily work for that gardener in that same soil in a very wet year. I have had to learn to adapt my planting/growing practices so that they work in whatever weather we're currently having regardless of what worked for me the previous year or the year before that. People with well-drained soil do not have to worry about root crops rotting nearly as much as folks with slow-draining clay do.

Since moving here, our yearly rainfall has ranged from just 19" in our driest year to about 52" in our wettest year. I plant my garden one way in very dry weather and an entirely different way in a persistently wet season.

So, it's not about "if it ain't broke, don't fix it". It's about adapting to whatever weather you're having in the current year, not whatever weather you had the year before.

Like oldokie, I plant potatoes more shallowly or in above-grade-level beds when the weather is persistently wet and I plant more deeply and/or in grade level rows when the weather is persistently dry. You have to go with the flow.

So far this year, we are persistently wet and I am adapting all my planting plans accordingly.

Dawn

Ah, geez, I'm so sick of Oklahoma weather.

Dawn,
After reading and thinking about the same issues for some time, I have decided to plant into raised rows in the Spring and in trenches for the warm season. Trenches (on the contour) tend to catch and hold the little rain we get here. However, I realize I have to build the raised rows in mid Winter when it is dry. We usually get a few nice (almost warm) days each winter. The trenches are created by my seed planter. They are great for irrigating with drip tubing too.
I am prepared to adjust for conditions as you mentioned but I like to think we can mitigate some severe conditions with sound standard practices.

I shouldn't complain. this bed I'm working is only a year old. I have good dirt. Reminds me of something: "Don't wish it were easier, wish you were better." ~ Jim Rohn

Mr. Coleman, I'm thinking berms and swales and with micro irrigation for the dry years. I have a lot of water running onto my property (which is why my soil is so favorable). My calculations show I can triple my underground water capture with the right permaculture set-up. Oh, the want for a trench digger!

Bon.
If you till a strip, rake the dirt down slope then repeat the process about four times, you will have a very nice swale.

That makes perfect sense.

Johnny, With the kind of clay I have here, having at least some raised beds is the only way to grow some things that will otherwise rot in a wet year. For me, the problem is that we really don't know at planting time if the whole year will be wet or if only a portion of it will be wet. Most of what I plant in raised beds is planted in February and March, and occasionally into early April, so except for tomatoes and sweet potatoes, my raised beds are mostly filled with cool-season crops. If we are going to be deluged with rainfall (like what is happening so far this year) it normally will happen in March, April and May.

Most of my warm-season crops, including corn, okra, southern peas, squash, and beans are planted at grade level, preferably at the western and northern edges of my front garden, or almost anywhere in my back garden which is about 70% sandy with the 30% that is clay being along the eastern and northern fence lines. I don't dig out trenches for water or irrigation, though, because when I did that, the pine voles moved from the woodland to the garden (in 2011 and again in 2012) and used the trenches as vole highways to travel around and then bore a hole through the side of the trench to access and eat the plant roots and plants. If I didn't have voles, my whole sandy area in the back would be waffle gardens. The emergence of pine voles as pests after so many years of vole-free gardening is forcing me to change some of my growing practices.

I like the way you're going to grow your plants this year and I think you'll have the best of both worlds.

Because my front garden slopes from south to north and from west to east, I plant water-loving plants at the northeastern edge of the front garden and they benefit from all the water that runs downhill in periods of heavy rainfall. Of course, in periods of prolonged heavy rainfall, they may drown, but I seldom have periods of prolonged rainfall so it isn't a problem most years. I probably get more rain than you do most years. Y'all have had so much drought up there for so long.

I agree we can mitigate much of the weather conditions to a large extent. I never really have a bad garden year. Even in our two worst years here, 2003 and 2011, our garden produced plenty, at least through the end of July. It keeps me on my toes trying to anticipate what the weather is going to do and then figuring out what I can do to mitigate any negative impacts to my garden.

With a sloping garden, the pathways between the raised beds function almost like swales, often holding water for a couple of weeks before it gradually soaks in. I like that! It is better than having the water run downhill and erode the front meadow like it used to.

Bon, I created swales in my back garden the first year I planted it in exactly the way Johnny described. It did help hold/channel the moisture. I didn't use the big tiller to do it either. I just used my little Mantis cultivator. We have a big swale that runs from north of the barn-style garage to my back garden. It is a swale left over from when this place actually was part of a farm. It holds some water in place there in the hay bale garden, but once the swale in there is full (that ground is mostly level), then the water runs downhill through the swale and into my garden. It doesn't come into the garden as much as it wants because the swale is still just outside the garden fence, but some of the water runs into the garden and the rest runs right beside it. I'd love to dig a bigger trench to carry more of that swale water into the garden someday but because of the way the land slopes, it would have to be a pretty deep swale and it is likely that wildlife would take advantage of the spot where the swale meets the fence and would use that as an entry port into the garden.

I can understand. The fence line has created its own contour and one of the the berms would need to be right at the fence line. Putting a swale and berm at that point would defeat the purpose of the fence and also create an aesthetic problem.