Raised Garden

Aaron Beaver

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427
Location
Missouri
Anyone have one and have any suggestions, we are considering making the one show. I have made the widest part 4' across so you only need to be able to reach 2' from each side. Looking at making it out of double stacked 2x8's or 2x10's with 4x4 corner post and bolt it all together. Then drive stakes into the ground on the inside and attach those to the 4x4 post.

Anyway, just seeing if anyone had suggestions on a raised bed, height, material, etc.

Pic and sketchup file attached.
Thanks
 

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There used to be a PBS program called Square Foot Gardening - and there was a book by the same name. Lots of very good info between the covers. You might want to get your hands on one.
 
I've always wondered why that show and book were so popular. I guess it filled a niche and had a catchy name. It's extremely useful for a rear court terrace in georgetown, but for other situations... :doh:

Anyway, here's a start: http://www.google.com/search?q=rais...s=org.mozilla:en-US:official&client=firefox-a

Really, you have three choices:

1. build the bed right on the ground (lets the roots grow into the ground, but also lets things grow up...
2. put landscape fabric or black plastic under it (isolates the growing medium, but means you have to water. A lot!
3. put hardware cloth or metal mesh under it. (keeps burrowing critters out...

What to build it from depends on whether it's for ornamentals or food. If it's ornamentals, use treated landscape timbers. They're cheap, and they stack! I usually drill them, and drive rebar down through the holes, one on top of the other. Do not succumb to the temptation to stack 2x lumber. It will sag out, no matter how many posts you use, and the water will just go down around the edges of a dry bed, doing little or no good.

Four inches of height is plenty for a raised bed. What's your goal in building them? To simply define the area? To overcome drainage problems? To keep rampant plants confined? Or does the gardener have difficulty bending over? Those are the major reasons for a raised bed, and your answer will influence the construction details.

Growing medium should be heavily amended soil. Think half peat moss, and half "dirt". Local dirt. Like, what's there now... You may need to add some lime. Feed with a combination of foliar feeding and compost, or pure compost if you're inclined that way.

If you're growing food, the options for construction are more limited. You should probably stay away from treated lumber, and cedar, etc, can get pretty pricey quick. I usually solve that problem with tufa... which has the advantage of standing up to a Kansas winter... ;)

Thanks,

Bill
 
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I've always wondered why that show and book were so popular. I guess it filled a niche and had a catchy name. It's extremely useful for a rear court terrace in georgetown, but for other situations... :doh:

Anyway, here's a start: http://www.google.com/search?q=rais...s=org.mozilla:en-US:official&client=firefox-a

Really, you have three choices:

1. build the bed right on the ground (lets the roots grow into the ground, but also lets things grow up...
2. put landscape fabric or black plastic under it (isolates the growing medium, but means you have to water. A lot!
3. put hardware cloth or metal mesh under it. (keeps burrowing critters out...

What to build it from depends on whether it's for ornamentals or food. If it's ornamentals, use treated landscape timbers. They're cheap, and they stack! I usually drill them, and drive rebar down through the holes, one on top of the other. Do not succumb to the temptation to stack 2x lumber. It will sag out, no matter how many posts you use, and the water will just go down around the edges of a dry bed, doing little or no good.

Four inches of height is plenty for a raised bed. What's your goal in building them? To simply define the area? To overcome drainage problems? To keep rampant plants confined? Or does the gardener have difficulty bending over? Those are the major reasons for a raised bed, and your answer will influence the construction details.

Growing medium should be heavily amended soil. Think half peat moss, and half "dirt". Local dirt. Like, what's there now... You may need to add some lime. Feed with a combination of foliar feeding and compost, or pure compost if you're inclined that way.

If you're growing food, the options for construction are more limited. You should probably stay away from treated lumber, and cedar, etc, can get pretty pricey quick. I usually solve that problem with tufa... which has the advantage of standing up to a Kansas winter... ;)

Thanks,

Bill

Building it for food

goal: to make weeding easier, make it easier on the back, and also we just have a big rectangle for a garden now, so we have to walk through it to weed, pick veggies, etc. So being able to reach from all sides is the main goal.

Animals: We used to have a lot of rabbits but haven't seen those around much. Mostly squirrels & chipmunks

Dirt: The dirt below the 1-2" topsoil put down at construction (when it was built) is very thick, heavy clay. We have added lots of dirt, manure, compost to where we garden now, but the set up just isn't good.

Wood: I was thinking of using redwood, not sure what tufa is??
 
Building it for food

goal: to make weeding easier, make it easier on the back, and also we just have a big rectangle for a garden now, so we have to walk through it to weed, pick veggies, etc. So being able to reach from all sides is the main goal.

Animals: We used to have a lot of rabbits but haven't seen those around much. Mostly squirrels & chipmunks

Dirt: The dirt below the 1-2" topsoil put down at construction (when it was built) is very thick, heavy clay. We have added lots of dirt, manure, compost to where we garden now, but the set up just isn't good.

Wood: I was thinking of using redwood, not sure what tufa is??

Aaron,

Cruise around here for a while: http://forums.gardenweb.com/forums/

you'll find more info than you'll ever need... ;)

Tufa, or hypertufa, is a mix of portland cement, peatmoss, and vermiculite (or perlite). Most people use it to create 'naturalistic' planters and pots, but I think it's best use is actually for raised beds. One can make a tall frame of treated lumber, cover that with 1" chicken wire (to keep the wet mixture from sloughing, and the dried product from cracking), and then cover the frame with tufa. It solves most of the problems inherent in tall raised beds. But if you've got a cheap source of redwood, I can't think of anything better than that! ;)

Squirrels, chipmunks, and mice love to burrow into raised beds. Hard to blame them, really... ;)

The square foot guy used to do what we all do: build a frame, dig the soil underneath, and amend it with enough peat moss to build the soil up to the new level. Since then, he's gone to simply building a frame and dumping tons of potting soil (peat moss, compost, and vermiculite) into it, essentially making a giant pot. What he calls "Mel's mix" is what greenhouse gardeners have used for decades, in controlled environments. It would work, of course... but so would having a bunch of big pots filled with potting soil sitting on the middle of your lawn... ;)

If you've got heavy clay, it means you likely have some drainage problems, which raised beds will solve. If you've got enough redwood, go ahead and build them up, but make sure they're well supported (think of all the weight of wet soil... and trust me, it doesn't just push *down*, but also *out*).

Here's the wierdest thing: one of the best raised beds I ever had was in the site of a pond I had to fill in. It was 4' x 8'. I kept the 2x4 frame from the pond (the soil was very heavy clay). The pond had been 2' deep. I just threw back in the original soil, mixed with peat moss, and didn't worry about drainage (conventional wisdom would say I'd essentially have a dirt filled pond, 4 " above ground level, in which the soil would quickly sour). Au contraire... the whole thing absolutely thrived. I had a dahlia plant so big it literally required a 2x4 as a stake!

Anyway, your plan sounds pretty good to me. Just use a bunch of peat moss and compost to amend the soil! ;)

Thanks,

Bill
 
2. put landscape fabric or black plastic under it (isolates the growing medium, but means you have to water. A lot!

I disagree. If you build a raised bed, I think you'll have to water a lot period. It's raised above the ground, the water drains out, it dries out.

I've built my wife a couple of raised gardens in the back (for veggies) and they dry out. You must water them more than ground-level beds.

As for what to build them out of... I just built them out of cheap SPF 2x stock from the lumber yard. I forget if they are 2x6 or 2x8s. It's been 4+ years and they haven't rotted out yet. They will eventually, and then we'll just replace them. Considering the cost of cedar, or the cost of "artificial" wood (ie: plastic, or recycled plastic/sawdust/concrete thingies), I think just going with cheap construction lumber and replacing them when they rot is the simplest and cheapest.
 
I thought high was better, you know the old saying, 'high & dry', I have seen it on some gardening sites. I guess they are thinking better root growth if the roots have to go down and get it?

Art, what is SPF?
 
We currently have four raised garden beds, Each one is 4'x8' and is 20" high. They were made from 2"x10" spruce and are about four years old. They're just starting to rot out, so this is likely their last summer. Each one is held in place with a 2"x2" post driven 2' into the ground at each corner with one on the centre of the8' span making a total of six posts for each bed. We put a layer of straw and peat moss on the ground of each one before we added soil, so we find that we don't water them any more often than we watered our regular ground beds when we had them. This year we're going to grow through grass clippings to try and use even less water.

Attached is a picture. With these four beds we can pretty much stay ahead of all our fresh veggie needs as long as the produce is in season. We grow garlic, potatoes, tomatoes, beans, carrots, beets, cucumbers (on a lattice that is not shown in this picture), radishes and various herbs in the barrel. I also grow flowers in with the veggies. They attract the birds to the garden which keeps the bugs and grubs down.

cheers

John
 
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Currently I have one that is 20' wide by 30' long. In the spring it is getting redone and made into 4' wide strips. It is 15" high(rabbits) , drain pipes under it and a layer of fabric. The water is gravity feed via a 400 gallon drum that catches water from the shop roof. The bottom 4 inches are gravel to help the draining. So far it has been a exellent garden that is overflowing with veggies every summer.
 
Consider strawbale gardening as a first step. Davesgarden dot com has some good info on all aspects of gardening and is worth the price of admission.
 
Bill,

whats your suggestion if I have to go buy 'soil' to fill this thing? Just get top soil from someone and have it delivered or buy some in the bags from one of the big box store type stuff?

Since I have buy something anyway, could I get away with buying potting mix? Except it might be more expensive.
 
Bill,

whats your suggestion if I have to go buy 'soil' to fill this thing? Just get top soil from someone and have it delivered or buy some in the bags from one of the big box store type stuff?

Since I have buy something anyway, could I get away with buying potting mix? Except it might be more expensive.

Check with some nurseries, they usually have a good soil mix that they can deliver by the yard, or even the spot you need it. It would be cheaper to pickup as its usually $30 to $50 per yard.
 
Bill,

whats your suggestion if I have to go buy 'soil' to fill this thing? Just get top soil from someone and have it delivered or buy some in the bags from one of the big box store type stuff?

Since I have buy something anyway, could I get away with buying potting mix? Except it might be more expensive.

Aaron,

Potting mix will set you back a ton, especially if you build up the beds significantly. Some places will sell you "top soil", but you should think of it as fill dirt... I've never seen any actual top soil for sale... I've seen a lot of dirt amended with sawdust and sand, though. The stuff is cheap (as it should be), but the delivery charges will hurt.

If there's nowhere on your land where you can get dirt, here's your best option: buy a pickup load of what they call soil. It should be a third to a half of your total need. Dump it near, but not in, the built beds. Then see if your county has mulch. In most places, you can back up your pickup right up to the mulch pile, and take all you want for free. It's not the most pleasant work in the world, but it's not too bad. Bring a digging fork as well as a shovel. Trust me on that one... ;)

Dump it near, but not in, the beds. Then go to one of the big box stores, buy some peat moss, and some high nitrogen fertilizer. You'll need a few bags. The numbers on the bags will tell you what to buy. Look for something like 10-2-2. You want that first number high, because you're going to need the nitrogen.

If you lived east of the mississippi, my recommendation would be different... traditionally forested areas have a more acid soil, and you'd need lime, which would mess with the nitrogen.

So, once you have the beds where you want them, with either mesh or landscape fabric on top of the original soil level, start shoveling! ;) I usually make a 2' x 2' screen out of hardware cloth and 2x4s. this breaks up clumps, gets the rocks out, and helps with mixing. If you use a screen, you don't have to get in there and mix, and you don't want to ever, ever, stand on the soil in the beds. That would compact it, and you'd lose a big advantage. A couple shovelfuls of dirt, a couple of mulch, one of peaty moss, a small handful of fertilizer. Repeat. It goes pretty fast. When you get to the top of the bed, flatten it out so its level. Then water it in, with LOTS of water. You want to get the whole thing soaking. You'll lose a fair amount of volume... but that's ok... you want the top 3 or 4 inches to be pure mulch. That will mean no weeds, and you'll get past most of the watering problems. East of the mississippi, I've had raised beds I never needed to water, precisely because I used several inches of mulch. Your mileage may vary... ;)

If you do this as soon as the ground starts to thaw (or even before), they'll be ready to plant by the time the danger of frost is past. The beds will need a few weeks to settle in, so don't wait till spring... ;)

Oh, and there'll be a sign at the mulch place saying "only use this for ornamentals." That's because they have no control over what goes in to the pile. I never worry about it, but I make sure the beds have a few weeks to settle, with lots of water, so most of the yuck has time and cause to leach out. If you're a theory driven organic gardener, you can replace the mulch with homemade compost and more peat. :D

I know it all sounds complicated, but it's really easy...

One final caveat: no-one ever believes me when I say this... but even if you keep your construction costs low, it's actually cheaper to buy veggies at the store. Think of it in terms of woodworking: we don't build furniture to save money, we can't actually compete with the stores. We do it because we enjoy it, and because we can make exactly what we want. The same is true for vegetable gardening... we can grow varieties we can't find in the store, and we can be sure of how they're grown, and it's fun and challenging... :thumb:

Thanks,

Bill
 
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