- Hi, thanks for joining us for The Family Plot: Gardening in the Mid-South.

I'm Chris Cooper.

Raised beds are popular, and today we're going to see two different ways to build them and answer a few common questions.

That's just ahead on The Family Plot: Gardening in the Mid-South.

- (female announcer) Production funding for the Family Plot: Gardening in the Mid-South is provided by the WKNO Production Fund, the WKNO Endowment Fund, and by viewers like you, thank you.

[upbeat country music] - Welcome to The Family Plot.

I'm Chris Cooper.

Raised beds are a great way to grow flowers and vegetables.

The two most popular materials to build them with are wood and concrete block.

Here at The Family Plot, we have built both.

Today, we're going to take you through the beds we have built and rebuilt.

Our first raised beds were built with landscape timber.

gardener Peter Richards shows how we built them.

[upbeat country music] - Well look, these raised beds have been out here, what?

About two or three years?

- About three years, yeah.

- So a lot of people are interested in raised beds and they're interested in building raised beds of course.

So how did you go about building the raised beds here?

- Well these are actually the second set of raised beds I built.

I built a set for home.

- Okay.

- And we used the same pattern here.

Basically what it is, is it's just what you see.

It's just landscape timbers that are nailed together and you have to make sure that you get some good drainage so that you don't rot your timbers but other than that I find that these beds last, these last about 10 years.

With the landscape timers if you build them, there's a couple of different kinds of raised beds you can build.

One is you can just take dimensional lumber, so a 2x10 or a 2x12, set it on edge, connect the corners and fill it with dirt.

But those will tend to rot out faster because it has direct contact with the dirt.

The other extreme, you can build them out of concrete block or stone.

- I've seen those.

- And those will last forever.

- Forever.

- Right.

But these will last about 10 years before the wood rots out and you have to replace them.

- All right so, in order to get this ready though didn't you have to kill some of the Bermuda that we have here.

- Yeah.

- Yep, we went through and Mr.

D actually did a demonstration.

- He did.

- We killed the Bermuda underneath where we are gonna put the beds.

Once the Bermuda was dead we started to do the construction.

What we did is we dug a trench around where above, or rather below the wall where it was going to be.

We dug a trench down, it's about six to eight inches deep about eight inches wide.

I tend to use the width of my shovel because that's an easy way to get the same width all the way around.

Anyway, you do the trench and then when you're done with that, you take landscaping fabric and line the trench with landscape fabric.

You don't want to cut it narrower so it just lines the trench, you want to have all the extra and put the extra to the inside, you're gonna use that later.

And then you take the landscape fabric, that trench with landscape fabric in it, you put gravel on top of that, about four inches of gravel.

And the purpose of the gravel throughout the bed is to just to keep the water away from the wood because wet wood rots.

- Yes.

- So if you can keep your wood dry then it'll last a lot longer.

- That's half the battle is keeping the wood dry.

- Yep.

- Okay.

- So anyway, you put that gravel down, you tap it down so it's compact and flat.

That's one of the purposes of landscape fabric is to keep you from just packing the gravel into the dirt.

- Okay.

- Anyway, once you have that done, you go ahead and layout your bottom row of timbers which the top of the bottom row of timbers is gonna be just about at ground level.

So you do one row that's below ground.

And then you drive rebar in every eight feet this kind of acts as a big nail to hold the timber to the ground and then, from there, you just start stacking up the timbers.

And every row of timber you want to have set back about 1/4 of an inch because the dirt that you're holding back has a lot of force, especially if you have a really long, a wall like in a longer bed, you're gonna have a problem with, the dirt will actually bow the wall out over time.

Especially when it's wet it's extremely heavy and produces a lot of force against that wall.

So one of the things you want to do if you have a longer wall is you need to anchor that wall in the middle somehow.

And with our larger bed, we actually tie the two walls together.

We have a timber that runs under the ground from one side to the other on the second row of timbers and so that will keep it from bowing out.

And when you are nailing it together, you need to use a spike.

Just regular nails won't do it.

You want to use galvanized hardware all throughout because otherwise it'll rust.

And you want your spike to be long enough that it has to be able to go through the board that you're nailing, through the next board and into the board underneath that.

So, we used, I can't remember, it's somewhere around eight inch spikes and a spike every two to four feet depending on what you have.

And you just keep building it up.

I like to keep, as I'm going through the wood and picking the wood for the next course of timbers.

I always look, if I find a really nice piece of wood, I set it aside and then I use that for the top to make it look the best.

- Let me ask you this though.

So somebody's probably thinking that's a lot of hard work isn't it?

- It is yeah.

[Chris laughs] To build the three beds that we did, there were three of us working on it.

We probably had a couple of hours a day that we could work between our other responsibilities here at the station, but it took us probably two weeks to build them.

- Wow, okay, about two weeks.

- About two weeks, yeah.

- Now before you dig a trench, of course, you have to call 811, right?

- Right.

- You want folks to do that.

- Yes, we did that here and the 811 guy came out.

Because of where we are here, there's a lot of high voltage electrical and just television signal cables that are running around under the ground here and we just wanted to know where they all were because the worst thing that could happen is we're driving that rebar four feet into the ground and we hit a high voltage line and that's very dangerous.

Other things, if we went through a TV cable.

It's not deadly but it could knock us off the air and that wouldn't be good either.

- That's not good, we want folks to see The Family Plot.

So we don't want that to happen, of course.

How's the drainage here?

- Yeah.

The drainage in the garden itself?

- Yeah in the garden.

- It drains really fast.

- Really fast, okay.

- But something that we did is as we're filling the beds with dirt- - Okay, and what kind of soil mixture did you use to fill the beds?

- We actually used half of just screened soil, that's what it's called which is just clay and just whatever they dug up.

- Okay.

- And then the other half we used a garden mix which has a lot of additives.

It has bark and things like that.

- Okay.

- It's interesting to note, when you do that, the garden mix is gonna eventually break down and be great soil.

But it's going to take it a year or so to actually break down.

So the first year if you have really poor results in your raised bed, don't worry, it'll get better.

But what we did is as we were adding the soil, that's were all the extra landscape fabric comes in handy.

Is what you do is you take the landscape fabric, you fold it up against the timbers and then you put maybe an inch or two of gravel just inside the timbers and then you have the landscape fabric and then you have all your soil.

- Okay.

- And so the landscape fabric keeps the soil from getting into the gravel.

The gravel just lets it all drain and so, once again, you're just trying to keep the wood dry.

- Okay, so that's what we're seeing back here?

- Yeah, right there.

- Okay.

[upbeat country music] Those raised beds made of landscape timbers served us well.

They lasted nine years, but like all wood, they eventually rotted and needed to be replaced.

We decided to replace them with a more permanent option, concrete block.

While the materials are a little more expensive, these beds can last forever.

Now, gardner Peter Richards shows how to replace wood with block.

[upbeat country music] All right, Peter, what will we be doing today?

- Well, six or seven years ago we built these wooden raised beds.

- Okay.

- And as wood wants to do, it rotted.

- It rots.

- So the advantage of the wood bed was that it was much less expensive, but we're gonna go for more permanent solution this time.

- Okay.

- So we're gonna do concrete block.

Also while we're doing that we're gonna make the bed a little bit bigger.

- Okay.

- So the boards that are in it now are eight feet long and so the actual bed itself is two times the width of the board narrower.

So we're gonna expand it out, so the bed is actually four feet by eight feet, since the concrete block gives us a little bit of wiggle room there.

So let's go ahead and start taking it apart.

- All right, let's take it apart.

Ahh.

You got it?

- Yep.

[wood screeches] It's a good idea to water the bed before you do that, because that'll help the dirt all stick and you'll see it maintains the wall and we're just gonna build the wall around what's already there.

[gravel grating] So now that we've got the wood out, you can see the soil we have here and the way that this bed was built, is to help with drainage.

There's a lot of gravel here which we're gonna end up reusing.

So these are the blocks we're gonna use.

But, as you notice, there are a lot wider than the trench from the wood, so we need to widen this out a little bit.

We're going to lay out the corners and then we're gonna just dig a wider trench.

We're gonna reuse the gravel base, just for drainage.

If you're doing concrete block and you don't want this to be super permanent, you can skip the gravel layer, but you do need a flat surface to work on.

- Gotcha.

- Now, we're gonna stretch a string around the four posts that we've put in, and the reason for this is that we can level the string and then we know that for level underneath.

I have a string level, you hang it on the middle of the string and then you can adjust the string up and down and see if it's level.

Okay, now I'm showing that your end is high.

You don't have to have a string level to do this.

You could just do it with a regular straight level.

One more time.

One more tiny tap.

Okay, there we are.

- Good.

- Okay so now that tells us that this string from nail to nail is level.

So now we're gonna go ahead and do that on... - The backside?

- On all the other ones as well.

[light hammer thudding] Stop, there you go, that's good.

Okay, so now that our string is level, we're gonna start putting down our blocks and this is the longest and most frustrating part of this whole thing, [Chris laughs] because this first level has to be flat or level.

Once the first layer is level then you can just throw blocks on top of it and they're already level, so that's good.

So what we're gonna do is, here's our first one.

And just looking at the string, the string has a lot more space down there between the rocks and the string, than it does right here.

So that just means that we're gonna have to dig this out and we're gonna try and put our first level at the same, so the top of this block is at the top, is at the string.

So we still need to go down a little bit.

And we may have to dig out here and put some gravel back in.

Okay, let's try this one.

We're getting close.

[hammer thudding] About an eighth of an inch high.

Now, we're using these concrete blocks, you can use cinder block, you can use any other brick, anything like that, just the same idea, you just have to give that first level straight.

Okay, so our block is level or close enough and we're at the top of the string here.

So this first block we're gonna say is laid at this point.

So now we move on to the second one.

And, I can see obviously it's tall or it's high, so dig some out, and the second block.

Okay, well I'm gonna need some more over here, to level it.

And the whole thing is high mainly at right here.

Try it again.

[hammer thuds] Okay, so that one looks good.

Let's see how we're doing here.

It is just a little bit higher than this block here.

It's a little rocking so let's [hammer thuds] tap it down in a little more.

Okay, that's good.

Now on to the third block.

We put down the gravelbed, mainly because it was already there from the previous one.

You know if you just have level ground and you don't want this to last a long time, you're willing to come out and fuss with re-leveling the blocks every couple of years, because they might've settled or something like that.

You can just do this on bare dirt, but you do need to make it level.

- Gotcha.

- And you don't want to have the block touch the string, 'cause then it'll push the string one direction or another.

Also, if you're going any taller than probably about a foot to a foot and a half, you're gonna want to put it on a gravel base.

Because at that point, if you are out there working in your garden and the wall fell over, it could hurt you pretty bad.

Okay, so we've done most of this edge, we're getting close to the corner here, so let's put this block in, this will be the last block facing this direction and check to see if it's level here.

Okay we're pretty good, it seems like we're a little low in the front, so you can do is you can just lift up the corner of the block and kind of just pound some gravel under it, so you don't have to actually take it all the way out.

Okay, so for the corner here what we're gonna do, is we're gonna start because I don't have enough space here for another full block, I'll just turn it and start the next wall right here.

We'll just continue to level here and... Whoops.

Sorry about that.

And keep going.

[hammer thuds] Okay.

So now let's check it.

- Let's see how good you are.

- It's good.

- All right.

- At the corners, you can kind of go like this and get an idea several blocks long.

So, the first row is done that's the hardest part, 'cause once this is all level, now we have to do is just stack the blocks up.

- Stack.

- This is easy, so now all we do is we're just gonna take it, put the block on top, offset it by half and just go around and we just have to go around two more times, we'll be at 12 inches.

So if you want to grab some.

With stacking the blocks you got to look 'cause the different blocks that you use will have a recommended maximum stacking height.

In this case, they give 12 inches, so that's three tall, that's what we're doing 'cause that's how tall the beds are anyway.

Others you can go higher, if you wanna go higher than that, you have to start getting into engineering it.

Most places if you go higher than three feet, you actually need to have a permit and have it inspected, because there's a lot of pressure back there.

You know, if you have a lot of wet soil, you got thousands of pounds of pressure pushing against that wall, you have to be careful.

Here we have a problem that you might run into.

There is a hole that needs to be filled but it's too big for a block the normal way, so there's a couple of ways you can fix this.

So you could either put a block in sideways like this, which works, you might not like the fact that it's not broken like this face is, or if you want to, you could go ahead and take the rest of the blocks in this, on this side and put a little bit of a gap between them kind of like that.

What you're gonna do is pretty much up to you and what you wanna see.

I'm gonna go ahead and put it in sideways, if this were a longer side, I might space them out, but since there's only five blocks here, it's gonna be big gaps that you're gonna have dirt leaking out through.

So you got the last couple, I'll let you do the honors.

- Yeah, let's do it.

- Yup, there you go, now we've got a little bit of gap, so just scoot, - Yeah, look good.

- Scoot the last couple of blocks, and kind of divide that gap between a couple of blocks.

Okay, good we're done with structure.

- Yeah.

- We have to clean up our dirt here that's around on the grass, which because we have that trench for the rocks, we can just go ahead and rake it into that.

- Okay.

- That makes that easy.

And then we're gonna have to fill the bed, because we have some extra space, so we'll take some compost and we'll bring it in and fill it in.

This is block right now.

The way that the prices are, this is cheaper than wood.

When we built the wood originally, the wood was cheaper that's why we did it.

So you just kind of have to shop around, see what there is.

- Okay.

- Decide how you want to build it.

[upbeat country music] - Those concrete block raised beds will grow many plants in the years ahead.

Raised bed gardening is not quite the same as growing in the ground and it raises some interesting questions.

Here are the answers to some common raised bed questions.

[upbeat country music] "This year I put in a raised bed garden "with pressure-treated lumber.

"Is this safe for growing vegetables, "or is there a concern about arsenic leaching into the soil and getting into the veggies?"

This is Neal in Dublin, Ohio.

Peter?

- So, yeah, arsenic is, if you just built your raised bed last year, arsenic's not gonna be an issue.

Because in 2004, the EPA banned arsenic from pressure-treated wood that homeowners can get.

- Right, and that's CCA.

- Right.

- That's chromated copper arsenate.

- Yeah, the chromium and the arsenic, which are both not good for us.

But if you've built a raised bed after 2004, a couple years later, which probably, if it's a wood raised bed, you're probably gonna have built it since then anyway, 'cause they don't last forever.

But anyway, so it's not a huge issue.

The copper can still leach into the soil, but something you can do is if you keep your pH where vegetables like it, so, you know, 6.5-ish, it tends to bond very tightly to the clay and organic matter in the soil, and it won't go into the plants.

As you get more and more acid, it becomes freer and freer.

And then the other interesting thing is that plants tolerate copper much less than humans do.

So, we need copper, just a little bit, to be healthy.

And plants need copper a little bit.

You know, it's a trace, it's a micronutrient.

But you're gonna find that the plants are not gonna do well, and gonna die before it would affect you as a person.

Because your body will just flush it out as you go.

- That's good.

- So as Booker said, if you're concerned, that plastic, you know, lining your raised bed with plastic will, you know, keep the copper out of the soil.

- And you're right too, Peter, you know, since 2004, of course, you know, the treated wood is now treated with ACQ.

Alkaline copper quaternary.

Right, which is a lot safer, okay.

Or how about other alternatives?

Maybe don't wanna use treated wood.

You can use, we used, what, cinder block.

- Yeah, you can use block, or use a wood that is gonna hold up a little bit better.

You know, a redwood, or a cedar, or something like that.

[upbeat country music] - "What kind of soil should I put in a raised bed and how deep does it need to be?"

And this is Johnny from Mineola, Texas.

So what do you think about that, Peter?

What kind of soil do you think Johnny needs for that raised bed?

- Well, soil wise, your native soil is probably very good for growing plants.

And so you want to have a lot of that in there.

If you just put in all compost or all manufactured soil or whatever, you're gonna have issues for a raised bed.

And so, you want to have some native soil in there.

Now that doesn't mean you have to go dig it up out of your yard somewhere else, you can buy native soil.

Check local mulch yards or soil places.

You can either go and pick some up or they can deliver it in a dump truck, depending on what you want to do.

But then also you can put in some organic matter.

And that will help to just loosen the soil, make the plants really like it, breaks down, gives some nutrients for the plants.

And as to how deep it needs to be, well, it all depends on where you're putting this raised bed.

So if you're putting it on soil already, then any height doesn't matter.

So you could have it, you know, two inches tall because the roots from the plants you plant in it can work their way down into the native soil underneath it.

Now if you have the raised bed, if you're putting it on concrete, you know, on a driveway or something like that, then you do need to have enough soil for the plants to be able to get the nutrients that they need.

And so at the absolute bare minimum, six inches, but you're gonna have problems keeping the soil moist if it's on concrete and it's only six inches deep, so you'd probably be better off doing at least a foot.

And then, you know, if you're on a surface that the water can't drain off of, you need to make sure that you provide drainage for your raised bed.

So don't be building a raised bed out of cinder block and put a piece of plastic inside it because it'll become a swimming pool and all the plants will die.

So a couple things you have to worry about there, but yeah, most people I think put their raised beds on the soil, in which case it's not, you know, how high is it convenient for you?

- That's the route I would take.

That's what I would do.

Anything you wanna add to that?

- And the organic matter, I would try to do 20% organic matter to the existing soil.

And that's usually a good number to be able to get them organic matter and nutrients to the plants and loosening up the soil a little bit without, you know, going so organic that it dries out too fast.

[upbeat country music] - "How do I keep my raised bed vegetable garden productive?

I've had declining success each year."

And this is Jim from Highland, Illinois.

So what do you think about that one, Joellen?

- Yeah.

Well, has he taken a pH test of the soil?

I mean, it might be lacking a nutrient.

I've had some raised beds and they weren't doing well.

And I'm like, "Well, what's going on?"

Well, when I did a soil test on it, they lacked nitrogen and only nitrogen.

So I put a little more nitrogen on them and then they did better.

He just needs to make sure he's doing that.

And I don't know what he's planting in there, but- - Well, he's growing cucumber, squash and cantaloupe.

- And tomatoes.

Hopefully he's not taking and putting them in the same spot in his raised bed because he needs to rotate the crops even in a small bed.

At the first year, he's got four- - Yeah, it's four.

- Vegetables.

- With the tomatoes.

Yeah.

- Rotate one this year, here, here, and here, and then the next year, switch it up and then every year put all the vegetables in a different spot because you can do that in the same raised bed.

There was room for it all to grow there in the first place.

They can all grow in different spots every year.

- Okay.

- And that would help too.

But I would definitely want to know what the pH is, and it may just be lacking nitrogen.

And of course, sometimes people with raised beds, when you pull your vegetables out, it takes up some of the soil.

He might need to keep adding some more organic matter to his soil to keep it all up at the right level for the plants to grow also.

- Yeah, that's what I would do, Mr.

D. So when I'm harvesting or when I finish harvesting, guess what I'll come back with?

Organic matter.

- Organic matter.

- Yeah.

So maybe leaf mold, compost, yeah.

And let it go to sleep over the winter with that.

And it'll break down and it'll add to the soil structure.

[upbeat country music] "Am I washing out the nutrients when I water my raised bed?"

This is from Dan in Horn Lake, Mississippi.

So Stephan, I know you do a lot of work with raised beds for the Shelby County School system.

What do you think about that question?

Are you actually washing out the nutrients from your raised beds?

- No, you're not.

Your plants will actually absorb the nutrients that it actually takes.

You'll be washing away all the nutrients that it does not need and also getting rid of the salt buildup, so it's actually a good thing to water those nutrients away.

- Okay.

You're definitely right about the salt.

Some of your fertilizers are salts.

So they need to be flushed out of the system every once in a while.

So yeah, Mr.

Dan, don't worry about that.

You're not gonna be washing out your nutrients at all.

[upbeat country music] Remember, we love to hear from you.

Send us an email or letter.

The email address is questions@familyplotgarden.com.

And the mailing address is Family Plot, 7151 Cherry Farms Road, Cordova, Tennessee 38016.

Or you can go online to familyplotgarden.com.

That's all we have time for today.

Thanks for watching.

If you want to get more information about raised beds, you can go to familyplotgarden.com or our YouTube channel @FamilyPlotGarden.

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We also have links to Extension publications about raised beds.

Be sure to join us next week for the Family Plot: Gardening in the Mid-South.

Be safe.

[upbeat country music] [acoustic guitar chords]