Lost cause? Raised beds, on top of clay, questionable drainage

[Anthony_Toronto]

I remember picking potatoes from my grandmother's garden when I was small (and nice deep carrots), and washing them off and having them go right into the pot (or my mouth, for the carrots), but in my yard I have had to construct raised beds over clay, as the builder removed all topsoil before adding a sprinkling back before sodding. Soil depth is between 8 and 12 inches, maybe that's being generous? Anyway just wondering if it would be worth it in any way to attempt potatoes in these conditions. When I tried witloof chicory a few years back (the 'belgian endive' experiment) they started off nicely but then the roots rotted beginning on one side of the plot and working its way across the other...maybe it was a bug of some sort but I suspected poor drainage due to the clay shelf the beds are sitting on. Containers probably not an option, but if I could mix in some taters between the kale, lettuce, basil, peppers, eggplants, onions, and squash then I'd love to give it a try, even with a few plants, if only to get a few servings of gnocchi. Thanks for any insight...and I may add another layer of 4x4's this spring and cart in another 5 yards of soil, but that might not have much of a material impact.

[Riceloft]

I'm considering trying potatoes in a future season under similar conditions. My raised beds are 12 inches tall. I AM considering digging down to the clay to pull another few inches of it out and top off with more compost when the time comes though. Just to be safe.

[Anthony_Toronto]

Hi Riceloft, re. digging down into the clay I just have one lesson that I learned...I planted grape vines a few years ago and knowing that they could have very deep roots I dug down deep into the clay where I was going to plant them, maybe 4 feet down. After a heavy rainfal the holes filled with water. A week later, the holes were still full of water. The clay did not absorb any water, and created in-ground pools. I worry that this would cause underground reservoirs of moisture that would prevent any meaningful drainage, and the only way the water would get out of these holes was through (a) roots using the water, or (b) soil in and above the hole wicking water upwards, but presumably that would only happen if the soil above was dry enough that wicking would take place, which even with normal regular rainfall would possible mean constantly soaked roots.

[Riceloft]

Originally Posted by Anthony_Toronto

Hi Riceloft, re. digging down into the clay I just have one lesson that I learned...I planted grape vines a few years ago and knowing that they could have very deep roots I dug down deep into the clay where I was going to plant them, maybe 4 feet down. After a heavy rainfal the holes filled with water. A week later, the holes were still full of water. The clay did not absorb any water, and created in-ground pools. I worry that this would cause underground reservoirs of moisture that would prevent any meaningful drainage, and the only way the water would get out of these holes was through (a) roots using the water, or (b) soil in and above the hole wicking water upwards, but presumably that would only happen if the soil above was dry enough that wicking would take place, which even with normal regular rainfall would possible mean constantly soaked roots.

Hmm, touche... I don't think my clay soil is quite THAT bad. Something to be thankful for, I suppose.

[Anthony_Toronto]

I was a little shocked at the lack of drainage. I tried scoring the sides of the hole with a shovel, with no change. Easy enough to dig a bit of a hole and test it out first! I didn't find out until after I had already dug 7 or 8 such holes, a lot of effort for a negative result.

[Doug9345]

Yep you found out what digging a hole in heavy clay makes and that is a bowl. Clay is used to seal ponds, canals and the like. If you have the energy and time you can pile half of it on top of the other. Hopefully you have a grade where the ditches created can drain.

[drew51]

I was recently looking at grow bags and in the reviews a lot were using them for potatoes. I know jack about growing potatoes. Like adding more dirt? What!?

[matilda'skid]

Seed potatoes are cheap; you only need a few because it sounds like a you are talking about a limited space. Not all plants react the same way. Most don't like poor drainage but maybe it was something else that killed the endive. And the weather is different every year. You won't know until you try in your garden. You could mound up some compost in the middle of your bed to make it a little deeper and add more boards when you can. New potatoes are very good. To me mature potatoes don't taste that much better than store potatoes. I love to rob just a few new potatoes and leave the plant growing. I used to put rotten straw on top and you could feel with your hands and pull off new potatoes. Now you have to worry that straw has herbicides in it.

[epsilon]

I've used vinegar tilled into the soil to remove the bonding that keeps it sticky.

http://www.minsocam.org/ammin/AM56/AM56_1082.pdf

This article has other sugestions that probably work better. which I assume if you get a pound of the glacial citric acid you could mix it into a few gallons then agitate with tiller to get it to "free up"

Gaston

[Anthony_Toronto]

If I can locate some seed potatoes locally I'll give em a try, and I have a large pile of dirt and clay and old much near my composters so might just throw some in that pile and see how they do...everything else growing out of that pile seems to be doing awfully well.

Cool, thanks for the link Gaston!

[ScottinAtlanta]

I put raised beds over clay - I just drilled some holes in the raised beds at ground level (on the downhill side) for drainage, and never had any problems.

[bestofour]

I live in the south and have nothing but red clay. I tiller the ground add compost and plant. My potatoes do fine.

[Anthony_Toronto]

Any suggestions on type of taters I should seek out if I want to pick and eat them young? Or that may fare better in heavier, not-ideally-drained soil, in my short season, in a northern climate that tends to go from cool spring to hot humid summer back to cool fall?

[epsilon]

I would shoot for wax taters like the reds. they give you more options to work with at the smaller stage plus they hold up better to cooking for what you would use them for.

[matilda'skid]

I would just get some that look good to you. Do you like Yukon Gold or would you rather have a russet potato or red skinned one. I would avoid the fingerlings for a first try. Those took longer for me. When I go to the garden center or feed store the seed potatoes are usually in a bin and I bag up the amount I want. They are also in the box stores. I don't live in your climate so I don't know which ones are sold where you live. I have never dipped mine in sulfur and they grew fine. Potatoes are easy to grow. You will get reddish bugs which you have to pick off the leaves. My link is Oklahoma advice but look for Okie Dawn's posts; all of them. Toward the end of the threat she tells exactly how she plants them. http://forums.gardenweb.com/forums/l...483316185.html