Trench gardening?

[NM_Shooter]

I live on sand.  Pretty much pure sand... with a layer of clay 2 to 5 feet below the sand. 

I want to start a new garden area, and am trying to figure out a cheap way to do this.

Previously, we built raised beds, but I don't have the time or money to build a bunch of them this year.  So I am wondering if I can sort of dig a trench in the sand, fill it with compost, mix in more sand, till, and use that.  Sort of an inverse raised bed... probably will have a little bit of a mound when I am done. 

The idea is to just amend the soil in rows where I will be planting.  But I don't know how well this will work out.

One of the big problems with the sand (and the water) is that it is very alkaline here.  ph of 8-9 is common, and most plants hate it.  Peaches are the exception.  I am concerned that if I mix in my existing sand, I am going to blow the ph. 

Should I just bite the bullet, put in landscape timbers for raised beds and be done with it?  Or is there a cheaper way to do this and get good results?

[MountainDon]

Try adding something with some sulphur; I think that helps alkaline soil. At least I seem to recall adding some to the compost we added to the small garden years ago. We share the problem. Over the years we have amended the soil with all sorts of stuff and the small plot now grows pretty good. Compost is good too I believe. There was something else we bought in bags that helped too. Forget what though. 

[ChuckinVa]

Google hugelkultur. Our friend Paul Wheaton has written on it and I believe our favorite Troglodite Glenn uses it in his gardens. Basically lay out rotting logs and put your soil on top of them and plant like a raised bed. It enhances the soil, helps keep moisture in the ground and i think would be a option for your type of ground.

[NM_Shooter]

Google hugelkultur.

I did see that technique... but I don't know if it would work well in an enviroment where there is very low humidity and even less rain / water.  I suspect that in order to get that to decompose correctly, a decent amount of water would have to be applied.  Water is pretty precious here.  I also am hoping for good harvesting this year, and I think that the rotting mound tends to get better after it has had time to season. 

[peternap]

You need to see what and how others in your area are doing it NM.

The rotted log is OK but it does take moisture and a LOT of nitrogen, so you will have to add nitrogen no matter what.
Add a little vinegar to your water. That will help the plants take up nutrients Alkaline soil usually blocks.

I would mulch heavily and add something like 10-10-10. Mulching will hold the moisture in and compost from the bottom up. At the end of the season, turn it under, lay down a layer of material (sheet composting) then turn that under before you plant again.

Adding the organic matter will gradually control the alkalinity naturally. In a way your lucky becauseI have to add lime to make the soil less acid.

You may want to try digging post holes this year, and putting lots of compost or good soil in, then planting in the holes. I do that in new ground that I can't plow and it works well.

[glenn kangiser]

Even if the wood/tree etc is not decomposing yet it will draw and hold about 5 times the moisture of soil and slowly release it back to the crop.  Extra nitrogen can be added in the form of chicken manure, alfalfa or commercial fertilized.  It will start to decompose and fungi will send out tendrils into the ground drawing moisture to it to decompose it and aiding your plants too.  Some plants may not like the wood decomposition products but I have not found that to be a problem.  I did have to cut the amount of irrigation water in half in the hugel bed area and even then it was a bit too wet.

Lots of manure if you can get it helps a lot.  You can compost it out in about 6 weeks if you keep it moist and turn it weekly or more often.  It helps sand or clay soil.  I find I need to add wood chips in my clay soil to help loosen things. 

Pill bugs - potato bugs - snails - slugs can be a problem with the wood and manure.  The baits such as Sluggo Plus or others can safely get them away from your crops unlike most sprays.  Note if if is not the Plus it is only effective against snails and slugs.  Pill bugs ate right through our turnips last season.  Other than that they are kind of beneficial.  Just had too many adding all of the organics so they attacked the crop too.

I just did a trench area in my old garden - it is a recommended method - also called double digging I think.

[NM_Shooter]

Got to thinking about hugelkultur. 

On our ranch, we have had logging activity about 50 or 60 years ago.  For wet spot crossings on the roads, they would dig a trench, lay a couple of large tree trunks down, and cover the top with dirt to make a mound.  The water would seep down around the trees and the top would dry out and support the trucks going over the top. 

Here's the weird thing... we put in culverts in these areas three years ago, and the trees that were taken out of the trench were 50 years old and hard as a rock.  No sign of decomposition.  WTH?  Maybe it was because the water is ice cold all year round?

We also have all these old saw mill sites up there too, with piles of old sawdust on the ground.  It is black as can be, but no growth of plants out the top of these 50 year old piles.  Why is that?  I would think that would make good compost and was thinking of taking a trailer load home, but I would hate to put something that is chemically toxic in my garden!

[Squirl]

That is what I was thinking.  Wood usually takes a long time to decompose without oxygen and added nitrogen.  Fresh grass clippings are also a source of nitrogen.  I'm not sure how many lawns you have around there.  Add in decreased water and I'm not sure how well it will work in your location.  I don't know how much area you have.  I would still probably try it over a small area. I would probably try and supplement it with a little wood chips to hold moisture, but not a large amount.  You initial idea I think is a pretty good one.

What grows well in that area?

[MountainDon]

Wood will stay preserved in wet ground and especially underwater.  A few years back I read about someone someplace (NZ ) who dug in bogs for ancient tree trunks. They would basically be mining prehistoric wood. Then they would do some thing special in the drying department and make uber expensive furniture.

[NM_Shooter]

Hmmmm... wood chips. 

I have a lead on some cost effective compost and wood chips. 

I remember seeing something about preserved trees too.  I think the ones I saw were at the bottom of a lake somewhere. 

Guessing that the decomposition requires some air, and that complete saturation is a bad thing.  The other issue that we have here are a really nasty case of termites.  Have to be careful about encouraging them!

[peternap]

Read up on anaerobic and aerobic decomposition.

Wood chips are good but if they're fresh watch them. They get hot.

[MountainDon]

 

Ancient Wood website

50,000 year old wood for sale

[considerations]

peat moss is an excellent moisture retainer and is quite acidic...should be a good soil amendment for your situation... elemental sulfur can be helpful but too much can also do damage.

Amazing the differences, the soil out here is acidic already....and I'd love to have a truckload of sand to lighten the clayey density....maybe we should start swapping truckloads of dirt!   

[NM_Shooter]

Ahhhh.... what I would give for a yard that stayed put when the wind blows.

[peternap]

My tomato patch is ready...another week or so to go.

[NM_Shooter]

Well, I wussed out and decided to stick with what I know will work.  Given the high price of compost here, I built some raised beds out of PT 2x12.  I now have an additional 96 sq feet of veggie space.

Still going to till in some chicken nuggets  and a little more topsoil. 

You folks who live on fertile soil.... Don't take that stuff for granted!

[Squirl]

I won't, as long as you don't take for granted that warm weather.