New Community Garden: Raised bed vs in ground

We are organizing a new community garden at our church. We are looking at 60-100, 10'X15' garden beds. The area is currently grass. We have all the irrigation water we need and much more. My impression of the "dirt" is clay, rock & glacial till.

I need input from all of you whether we should go with raised beds or in ground beds.

We can get heavy equipment to dig out beds and loosen everything up. Water pipes from the irrigation ditch are already in place.

Any input from those who have been involved with community gardens is immensely appreciated!

Let the debate begin & please tell people in other forums! :))

If one of the mediators can help us to spread the word around, I would really appreciate it. This garden is for the whole community and will include schools & educational events as well as helping the hungry & the homeless.

Thanks!

Sonny Canterbury
Church at Carbondale Organizer
Dave's Garden Member "Pewjumper"

I would make my decision based primarily on the reliability of percolation in the substrata, or on your ability to divert water from the entire area if percolation rate is slow (Is the area sloped?), and secondarily on the feasibility of amending the existing soil so it's workable/productive.

IOW - if you amend your existing area so it has quality soil that drains well, it has to have somewhere to drain TO. If you dig a hole (build a bed), no matter how large, in soil that won't drain, you can fill it with perfect soil and you still have only a bowl full of soil that will fill with water and hold it every time it rains.

If percolation is no problem, or if you can tile or use ditches to drain the area, your options are open.

Al

Pewjumper - have you ever dug a hole in clay soil and filled it with water? Doesn't drain very well, does it? If you dig trenches in your clay dirt, and fill them with good soil, they will not drain well.

I suggest you use raised beds.

Well, tapla seems to have explained it much better than I did - we were typing at the same time :)

Dave's has a whole community garden forum, btw, if yall want info about other aspects.

Keep us posted!

Sonny, quite a project here, I wish you the best. I took me four years to complete my 60ft x 100ft garden are which is pretty much the same material as you are speaking of. I removed rocks as big as grapefruit and made quarter inch screen shakers each year to remove the gravely sized rock. Since Helena valley was formed by a glacer, the top two feet of 'soil' as such was nothing more than clay (rock dust as I call it) and rock. Beneath this top layer of this material is solid bed rock. And I did it by hand so to speak. Vertually wore out a shovel doing it.

Then I received the gift of a new neighbor and his family of five, now six. Hank, the dad was impressed with my garden and we immediately became friends. Hank decided he wanted to put in a garden equivalent to mine. He did it in one half day. He rented a bob cat with a tiller attachment and within three to four hours had his garden plot completely tilled. Of course there were large clumps of grass and lots of bolders. but he put his munchkins to work. For a number of days they would fill their wheel barrel full of the rock and clumps of grass and haul it to the back of their lot as I had done to extend their yard into the highway culver which is about 40 feet wide with a six foot drop. The culvert or drainage ditch as it is referred to is extra wide and serves as a horse path.

Anyway Sonny, the point being for a couple hundred he got the job done in 4 hours instead of four years of hand digging. You just need to find a place to dump this material and maybe as I have done you can turn this into a lasagna garden or raised bed.

morgan

Sonny, sorry I didn't mention this above. Several have commented on drainage. I have haulled in about 100 pickups full of horse manure over six year period to incorporate into the clay soil. I use a Sears 26hp tractor/moweer with a pull behind tiller (could not do this job without it), and incorporated the horse manure into the garden each fall. I till it untill the 'buscuits' are well mixed into the soil. Usually take half a dozen passes at least. Although a good portion of this material was well aged originally it broke down nicely and with each spring tilling I had a fine looking garden to start with and zero problems with drainage.

I have now gone to well aged cow manure, the source which Hank came up with. We didn't get our fall covering of manure this year because of weather and other constraints, however Hank and I will be renting a dump trailer to pull behind my pickup to expidite the job come spring. As long as these manures are well aged I have no problem with incorporating copious amounts of this material in the spring either. Just make certain you till it well. Again, if need be you could use the bob cat method of tilling in the manure. If you could incorporate everything in one operation you could possibly do it in a day. It would take lots of hands, but I have no doubt you could pull it off Sonny.

m

Morgan, Al, Realbirdlady & HoneybeeNC,

Thanks for the input so far, horse & cow manure is readily available. I never knew that bobcats had an optional rototiller, now that is my idea of a garden implement! LOL ;))
Why do people always give me that incredulous look when I tell tham I am renting a backhoe or trackhoe to work on my new garden areas???

Realbirdlady thanks for the direction to the Community Garden Forum. Nobody has posted since August, but there was a link for The American Community Garden Association.

Right now we just held our first brainstorming session and it went really well. The public utilities director for our small town was there and he was really enthused about our plan.

I have only seen one area that seems to have problems draining, somebody wanted to plant a tree there and I didn't think it was a great spot....it died. Oh well, once we rip everything to loose the compaction from the heavy equipment that roamed over the area, amend and level things, all will probably be better. Still it is a lot of work over about two acres.

I learned that our church should be commited to a long term association with the gardeners who justifiably become attached to their plots and all the work that they put in to their soil. Why not? Gardening was man's first job!

Any more thoughts are always welcome!

Sonny

Honeybee NC,

No Doubt about it! The Boss would also show up every afternoon to check it all out! :O LOL

Another thought to add to your decision making is that mounded beds (without borders) used the "French Intensive" way offer up to 35% more gardening space.

Patti - "French Intensive" system sounds intriguing - do you have any tips or links?

>> horse & cow manure is readily available.

That makes it all possible! Consider trucking in as much as you can get right away, and using part of your space to compost it, so that you can turn in compost in the spring, and fresh manure in the fall.

I assume that you want the garden going the first year - otherwise, make your first year 12" of manure plus a cover crop to help suppress grass and weeds.

Could you do a phased implementation, where only half the area is gardened the first year, and half is given more extensive preparation? If you grow a cover crop on 1/2 or 1/4 of your space, you have a source of free mulch for the rest. Or even straw to throw down on muddy paths.

Maybe set part of the area aside for labor-intensive, ongoing work like screening soil, and time-intensive work like composting manuare. Volunteers may be easier to find if there is always a bunch of work waiting for someone ti have free time, so they can just walk up to it and start doing stuff.

Try to do as much tilling, screening and adding compost as possible BEFORE building raised beds with walls. Maybe go the first 2-3 years without any raised beds so you can till, screen, lime and amend the soil with tillers instead of hand labor.

Improve the soil with a lot of turned-in compost before you switch to low-till practices. Consider adding some soil innoculents like endomychorhizzia (spelling?)

>> mounded beds (without borders)

That sounds good, since it eliminates the need for wood or paving stones to make raised bed walls. And you could make mounds for the first few years to get good drainage and aeration, yet still level them off to plow in more manure, untill you have rich, organic soil with more humus than rocks!

Personally, I would plow or rototill both spring and fall for the first few years.

After that, you could make the mounds permanent, and add raised-bed-walls over time, as people contribute materials and labor. As the walkways are dug deeper, and added compost makes the beds deeper and more friable, walls become more desirable. Then, permanent trellises or supports could be added as well.

Some walkways need to be wide enough not only for wheelbarrows, but for whatever cart or truck you have access to, to move in more compost or manure each year. Maybe a Bob-Cat or small front-loader.

Maybe 1-2 central walkways should be wide enough for a truck, then cross-walks can be narrrow enough for just wheelbarrows.

Can you extend water pipes into the garden? Or just run some big hoses to central points, and smaller hoses extending from them. Would each gardener water his or her own plot, or would you water the whole area during dry spells?

I find it a huge advantage to have 1 foot or 18" less stooping to do, so raised beds are a godsend. Also, drainge, aeration and compaction are hugely improved by that elevation. Sometimes it seems like many of those with the most time for gardening are old enough that stooping is a challenge.

The narrower the beds are, the less people will walk on them! Three feet is great, especially if it's a long walk around to get to the other side. Four feet is OK. If you make some beds five feet wide, please also make some smaller, to see how eagerly people compete to get the narrow ones.

Screening out rocks would be great if you can find enough help up-front to do it. Even a 1/2" screen will help, and also it breaks up clay clods. Or do this incrementally over years, a few rows at a time.

The best place to put screened rocks and gravel is into the narrow walkways between beds!

Or dig the walkways extra-deep in the lowest part of the garden, call them "trenches", and then backfill with rocks and gravel over the next few years.

Maybe dig your "wet spot" even deeper, using that soil to make the dry parts higher. Than add a drainage trench below your current wet spot.

Corey

Nice job Corey...you get 100 ataboys for that posting.

Don't make raised beds out of nothing but compost, though. I found out the hard way that without some mineral portion (topsoil, clay, pea gravel) the bed will compact & begin draining less freely as the organic material decomposes. I wound up with bushes that had exposed roots after a couple of years.

I now think of the mineral part of my soil as part of its skeleton (along with plant roots).

Honeybee all I can really relate about French intensive is that you plant on the sides of the mound. That's where the extra space is. I never border my beds for that reason. Those mounds have plants all around the sides so it is stabilized by the roots.

Thanks very much, mraider!

I wish I wish I WISH that I had 15,000 square feet, heavy machinery and access to copious manure! But I bet it will cost a pretty penny to do everything desirable to make that much space prime garden soil.

Free manure/compost solves many problems, but he'll still have grass roots, weeds, rocks and stones. If he has no time pressure, maybe do a large-scale "lasgana" move and cover everything with a foot of manure for the first year! While it composts, grass and weeds will die.

Corey

Time to encourage all the church members to start bring in bagged leaves, lawn clippings and shredder paper...designate a drop off pile so you can keep it coming...

Might wanna consider asking for clippings from untreated lawns only...

PuddlePirate, I agree completely.

>> Don't make raised beds out of nothing but compost, though. I found out the hard way that without some mineral portion (topsoil, clay, pea gravel) the bed will compact & begin draining less freely as the organic material decomposes

>> I now think of the mineral part of my soil as part of its skeleton (along with plant roots).

I would go further: compost plus clay doesn't work either. As soon as the organic material starts to decompose - which it does as soon as air and water reach it - it starts reverting to pure clay. How long does fine organic matter survive in healthy, well-aerated soil? I notice that we have to replenish it every year! Wood and confier bark last longer than most things, but probably not more than 3 years.

And even before that, the texture and tilth of "soil" that is made up only of very fine particles might be soupy pudding, or might be like mortar, but will have no pores, no drainage and no aeration.

I notice that you didn't mention sand. In my area, even bulk-delivered "topsil" tends to be clayey and not contrbute much to the "granular" or "gritty" part of soil structure. I love your word "skeleton" and I plan to use it from now on!

Would you agree that coarse sand or grit (sizes like 1/6th - 1/8th inch or 1-2mm) are valuable as part of the soil skeleton?

The conventional wisdom may not be true that "clay plus sand equals concrete".

Actually, clay plus compaction equals mortar.
Clay plus compaction plus sand equals concrete.
Clay plus compaction plus compost equals pudding.

Only balanced soil can withstand any compaction - sand/gravel/grit for skeleton, PLUS organics and gypsum for adhesion, all combining to make STRUCTURE that resists compaction and rain.

My belief is a very old-fashioned view: that "good soil"requires a balance of all things: sand/humus/silt/clay/air/water, supproting both fine and coarse "structure": stable porosity and stable "crumbs".

(When I say "silt", I mean both organic matter breaking down into colloids, and mineral grains smaller than fine sand I'm not sure whether that is technically correct.)

Coarse, resistant organic matter like twigs, wood chips, shredded conifer bark, wood fiber, coir, and peat probably can serve as "skeleton" as well as coarse sand, or even better, except that sand is forever and organics decompose. I've been using pine bark this year, and expect it to do very good things for 2-4 years, after which I may have to turn more under.

My plan is to get coarse sand into the deepest part of the soil ASAP, to serve as "skeleton" so that I can keep reducing the amount of turning I do.

Worms, frost, and the expansion/contraction of clay as it wets and dries do serve to churn the soil very slightly and very gradually. Roots that force their way into aerated clay and then die do leave channels behind, but they don't penetrate clay that is anearobic due to lack of drainage.

I want the soil 12-18" down to have "some of everything", including air and drainage, in the first few years of cultivation, and not have to wait for worms and geology to perform 'pedogenesis'.

Compaction can occur in awful soil due merely to its own weight! If no one ever walked on a bed - and we had no gravity - and rain only fell gradually and as a gentle mist - you could probably fluff up heavy clay soil and then expect it to retain air spaces and drainage. However, walk on it or get it wet "while gravity is turned on", and it will squeeze out any air pockets and turn back into pudding or concrete.

The "skeleton" resists that by acting like the framing in a wooden house, or the matrix of I-beams and rigid floors in a skyscraper. It bears the load so that soft, fine soil fractions can nestle in the interstices without washing out or squashin flat.

Presumably soil with good enough "crumb" structure may serve as its own skelton. If strong enough, "crumbs" could act like gravel or coarse sand, retaining pores, air space, and water drainage despite their own weight, even when wet.

I have never had soil with good enough structure to withstand being walked on, at leawst not by fat old me. maybe that is only becuase I never had access to as much compost, manure or sand as I would like, and have moved out of most places I've lived in relatively few years.

Corey

WOW!

Thank you so much! There is so much to think about here! I will give members of my committee a printout of this so far. The ideas here are amazing in that I knew of some of them, but had forgotten. Others, such as French Intensive is completely new to me.

Somebody on our committee mentioned using certified weed free straw bales to frame raised beds. Which sounds like a great holistic way to garden. Kinda like that Japanese candy I tried as a kid, you ate the candy, wrapper and all.

You can make good balanced soil out of clay.
1) Wait until the clay dries and has only some moisture.
2) Run it trough my handy dandy two stage strainer, (see picture).
3) mix with coarse sand 40%, clay 30%, peat moss 15% & acidified cotton boll compost 15%, (we have basic pH soil conditions).
4) Voila! You have garden loam that is a little gritty, but yearly additions of manure/compost will make it into a primo soil.

Again, much thanks for all the GREAT suggestions!

Sonny

That sounds like it will be great soil, with 30% organics and 40% sand, when the other 30% is already good enough to support grass!

The straw bales sound great if you can afford them:
this year raised-bed walls
next year, mulch
third year: compost

I didn't have room, budget, or leaning-over-strength for straw-bale walls, but I envy all that carbon you can add. I hope some people try planting tomatoes directly in the bales!

I guess that 10x15' beds need much less wall material than narrower beds would, like 5'x30' or 2 beds each 3'x25'.

If I had a 10'x15' plot, I would try to dig one walkway lengthwise, turning one plot into two 4.5'x15' beds. Or even dig three 1' walkways the short way, making 4 beds each 3'x10'. Less reaching, and no reason to walk on the soil.

At first I thought that 100 10x15' beds would be many acres, but counting on my fingers seems to say only 1/3 acre! Did I drop a digit somewhere?

Say, what would it take to get a plot there? I'd convert! But it sounds like a long commute ...

Corey

patti47 - thanks for the input regarding "French Intensive" - I don't think that's something I could incorporate in my own garden. Our little dog has been taught not to cross a wooden board - which keeps her out of the raised beds. I can just imagine her curling up on a mound thinking it was put there for her benefit LOL

My cat is sure that I dig, turn, amend and rake beds for him to use as a litterbox. Once the plants are very well established, he doesn't dig there any more, but until then, YUCK. few seeds survive a cat excavation.

He seems to recognize that Thai Hot Pepper flakes "mark the spot" as being in use.

And chicken wire is a complete deterrent.

Corey

Corey,

No one needs to convert, unless we are talking inorganic vs organic methods! LOL :)

My church & I beleive that with all the hurting people out there, this is a chance to give something that will lift peoples spirits & put healthy food on the table. When you don't have a lotta money people can only afford the unhealthy stuff. I don't know about others, but my spirit is always lifted a little bit when I do my afternoon garden check. There is nothing like sitting in the shade with a margarita watching the birds & bees doing their thing. The hummingbirds are always entertaining unless they buzz the tower.

Which reminds me that I need to put up some mason bee nests when the soil gets soft and dried out.

Sonny

>> No one needs to convert, unless we are talking inorganic vs organic methods! LOL :)

Too true, and, if you'll forgive the usage: "Amen!"

I've encountered fervent belief systems and True Believers of all sorts here in DG, though the topic of religion seldom comes up. In one forum (was it Winter Sowing?) I was warned not to even RAISE the question of which seed starting soil mix was best, because once upon a time those threads got so heated.

I really strongly respect both the "cold" and "hot" schools of compost makers for being so civil to each other, despite such strong feelings and divergent values and beliefs. They set a standard that I wish the whole world followed, in religion and politics both!

On the subject of composting, Kylaluaz just turned me on to the Eastern European practice of
"Hugelkulture". It is composting, with "mostly wood" as a starting material. Wiiiilllld and craaaaazy stuff!

Corey

I think that soil ammendment is the key to raised vs in ground. We can create as Rick says all that is important. I think all plants want the drainage of raised vs in-ground. Build your womb to raise your children as you want.

To all,

We have two areas we are considering for The Garden at Carbondale. We will probably go for the smaller area at this time which will accomodate the equivelent of 30 10'X15' beds. Although we will probably make the beds narrower & longer in order to make them more easily accesable.

After looking everything over, I think raised beds are the way to go considering all the things involved.

The details are coming together & your help has been greatly appreciated. Many of your thoughts will go into this community garden.

Keep your thoughts coming! I will post pictures and keep you all informed as to our progress.

Thank You! :))

Sonny

Best wishes and good luck!

Corey

Corey you mean like this? I've been a strawbale gardener for about three years now and as far as I'm concerned I'll never grow tomatoes in "dirt" again..

And it doesn't take two years to make compost! It will be crumbly dark brown by the following year. For the past two years I've just grown the tomatoes in the boxed in bed in the decomposed straw from the previous year with great results. I also grow some in new bales too in the open rows.

Doug

Drool, drool, DROOL!

I don't know which I envy more:
- the big yard
- the glassed-in sun porch
- straw bales and trees (sources of compost)
- summers warm enough for tomatoes and peppers
- mini-tractor and cart

Well, the big yard is the best thing.

I think my compost goes slowly because the "pile" is so slow, and it is all brown or stiff stems. Hardly anything soft, and very little green. Whatever I put in that's soft or nitrogenous disapears fast.

I'm about to splurge on two cubic yards of "store-bought" compost. It bothers me to pay that much when I know the "compost" part is mostly sawdust, and that, even on top of that, they add more wood shavings AFTER composting. Oh, well, the soil needs carbon, too., even if it is woody.

Lately I've become fond of shredded pine bark, when I can find bags that ARE fine, and are mostly BARK and not wood chips.

Kyla turned me on to "Hugelkulture" which I interpret as "composting for those who mostly have wood". So I'm goin g to use a coarse screen on some "pine bark mulch" to pull out the bigger wood chips, and "huglekulture" them in a part of the yard that even weeds disdain.

Corey

Why spend money on compost? http://seattle.craigslist.org/search/sss?query=compost&catAbb=zip&srchType=A&minAsk=&maxAsk=

That's a good tip - thank you. I found someone with manure only 15 miles away.

If I had a truck, it would be a great tip. Of course, with a truck, I could get free biosolids at about the same distance.

I was thinking of lining the truck with plastic, then seeing how many 5 gal buckets of biosolids would fit. "Manure" sounds better, but I don't know which has more nitrogen.

Corey

Check for nearby llama or alpaca farms. I hear their manure is wonderful compared to horse apples.

I guess there's farm country a lot closer to Seattle/Everett than I thought. It's not all used car lots and baristas.

Corey

North Cascades Highway has quite a few farms doesn't it?

Doug

I don't know North Cascades Highway - MapQuest says "Vancouver, WA", a 3 1/2 hour drive south for me.

The town of "Snohomish" has a feed store and nursery wholesale supplier, 15-20 miles east of me. A couple of gallons of gas is $7 and my trunk might hold that many cubic feet ... but I can buy bagged composted manure for $1-$1.25, and not have to shovel un-composted manure out of my trunk.

I really need to find someone with a dirty old truck, and do him or her a bunch of favors.

Corey

Postmandug,

Thanks for the info on strawbale gardens. I think that is the way we will go, at least for the first year in the new community garden.

I have decided to go with raised beds because the soil warms up more quickly in the Spring. Using bales of certified weed free straw will save a lot of money in start up costs.

Thanks again! :)

Sonny

North Cascades Hwy begins in Skagit or Sedro-Wooley I believe, right above Whidbey Island. It's a beautiful drive. Try it sometime. Here's a pic from Mt Erie in Anacortes looking back toward Whidbey Island.

Doug

I have big yard, big compost, and sun room so I am blessed. I often have compost left over living in zone 4. My garden is happy.