Foundation Ideas for Raised Beds

Hey all,

I've re-purposed some pallets into raised beds, and they ended up being 15" tall. I've got just enough soil to create 6" soil layers, which leaves me to figure out how to fill up the bottom 9" -- I'm looking to see if anyone can think of an ingenious/cost-effective way to accomplish this goal.

I am thinking of using Pea Gravel (I would need 1.5 Cubic Tons, which comes to around $60 dollars if I buy in bulk from my local garden center), but wondering if anyone else has any other ideas that would be more cost effective?

 

First, can you borrow a saw and slice the beds in half so they are only 7.5" tall?

Second, can you just put as much mix in and leave the sides higher?

Third, if you are going to put something in the bottom to raise the level of soil, why not something the plants will use, like straight compost?

Any pictures?

ETNRedClay wrote:
Third, if you are going to put something in the bottom to raise the level of soil, why not something the plants will use, like straight compost?

This was my first thought! If you can get to any farms near the city you may be able to score a load of manure that you can use to fill up the bottom, then put your mix on top.

GG

Things you might be able to scrounge for free:

wood chips
broken concrete
sand
2 liter pop bottles
plastic milk crates
5 gallon buckets
CMU
firewood
fill dirt

+ 1 on the woodchips!

go to a recycling center and get old news papers, cardboard, phone books, plastic bottles

grass clippings, leaves, pine cones, sticks, rocks, sand

you could put a free add on craigs list looking for composting material   

happy gardening
rose

Thanks for the ideas guys! I'm thinking I'm going to pick up 1.75 cu yd of either "Triple Shredded Bark Mulch" or "Woodchips" from the local mulching center. This should be cheaper than Pea Gravel, will provide good drainage, and if any of my roots happen to go below the 6 inch layer of Mel's Mix, they should be able to benefit from the mulch/woodchips more-so than some rocks

Just my two cents. I'd put in compost under the MM. That way when your roots go through your MM, they will have some really good nutrition to get their roots into. Straight wood chips won't have a lot of goodies for the plants. Again, this is just my 2 cents! good luck!!

Southern Gardener: Thanks for the two cents!

I have 6 beds, each 38" x 38" x 15"

That means, 38" x 38" x 6" of Mel's Mix = ~1.2 Cubic Yards

That means, 38" x 38" x 9" of ????? = ~1.75 Cubic Yards

I think I can get 1.75 Cubic Yards of Compost for $61.25, so this idea is actually REALLY smart   

THANK YOU!

 

EDIT: My only question is, would this not be so great for drainage?!

I would go with something that is beneficial for the plants. Compost is a good idea or even straight manure might be possible if you can find a good source of it.

If I had the extra space I would try hugelkultur. You could try using some old wood under your beds and sort of mimic a small hugelkultur. Sine you have multiple beds you can try different things in different beds. If I could find enough free manure for only one bed I would take it and then only worry about finding something for the other beds. I would also seek out free or very low cost options options first.

In my experience it takes a lot of manure and too much muscle work.  You need to keep pounding it down into a hard layer or else the contents settle way too much and very fast, even before the growing season ends.  But the plants did very well last year using llama manure as a bottom base. Can't say how other manures would settle or perform overall.

Mel's mix is your Gold Standard.  It's wonderful stuff and very successfully stands alone as your growing medium which I've used for years.  The manure experiment was implemented only  because I have free access to so much of it.
 

I wouldn't worry about drainage with a compost base. The only drainage that is really important is the 6" of MM. In my limited experience, organic matter sinks a little. I fill a box to 6", water a few times and it has settled some. The only good thing is that I can add more compost and still have room for 1-2" of mulch.

Are you going to put anything between the compost and MM to define it? Like newspapers or weed barrier? Or are you only going to clean roots out of the first 6" every time?

tumtumsback wrote:...I have 6 beds, each 38" x 38" x 15"...

Are these in addition to your wicking boxes?

tumtumsback wrote:Southern Gardener: Thanks for the two cents!

I have 6 beds, each 38" x 38" x 15"

That means, 38" x 38" x 6" of Mel's Mix = ~1.2 Cubic Yards

That means, 38" x 38" x 9" of ????? = ~1.75 Cubic Yards

I think I can get 1.75 Cubic Yards of Compost for $61.25, so this idea is actually REALLY smart   

THANK YOU!

 

EDIT: My only question is, would this not be so great for drainage?!

You're welcome. I don't think it's going to be a bad plan as far as drainage. I would recommend getting GOOD compost though. don't cheap out on it, it's not worth it. $61.25 for that much material is a good price! I'd go for it for sure if it was me, and it was a good compost!

Thanks as always for the replies yall!

Sanderson: Correct me if I'm wrong, but if I am reading what you are saying correctly, I'm going to have to sift through my 6" of MM at the end of the season and remove any roots before I start back up next season? ::My newbie-ness is showing::  

What do you use to "define" your MM layer? I don't see a problem using some weed barrier and/or newspaper, I definitely have access to both...

Boffer: I think I am scrapping the idea of the Wicking Beds. I am going to water from above straight up! For doing all of this work, I cannot risk the idea of not having adequate moisture. At the most, I will only be absent from the garden (vacation, etc.) for 3 days in a row at the most, at which time I can have a neighbor water the garden for me.

Southern Gardener: The compost I am getting is high quality    I'll continue to post my results this Spring/Summer/Fall  

You don't need to define a layer. Blending soils (and/or soil-less soils) a bit at the dividing line is the best way to do it, according to the Master Gardener's course I'm taking. People who plant trees often do the same thing as veggie gardeners. Otherwise the roots sometimes stop and start to circle with trees, on encountering the different soil. Same with gardening veggies, if you plant things with deep roots. They can go wonky if they meet a sharp dividing line. With a gradually changing soil interface, though, they'll happily keep on growing right through.

Tumtumsback,  Going straight to pages 61 & 64 of the ANSFG.  Use weed fabric under the MM.  For tall boxes, use sand as the bottom filler.  Ergo:  What ever filler, top with weed fabric or other barrier like newspaper, clear cardboard.  You are not using the filler material to grow in.  Marc is right about blending a zone between different mediums. However, that is only necessary for traditional gardening.  In purist SFG you are only growing in the 6" or more of MM.  For deep root plants like carrots or parsnips, you can built extenders (top hats) upward and fill with MM.

Now, these are your boxes for your garden.  You can do what ever you want to.  Just trust Mel's SFG method.  Dstack built tall beds for nematode control.  Cinder/concrete block perimeter, filled with clean sand, and topped with concrete (carefully sloped to drain good).  Then put his wood box with 6" of MM on top!!  I have some boxes on cement pavers.

Cleaning out the roots.  I found that some plants pull out rather nicely and don't leave a lot of noticeable roots behind.  I call that finger grooming.  But my tomatoes, OM goodness!!  The networks of roots were so thick that I had to remove the grids and drip lines and really get down and dirty.  Maybe they have LOTS of roots because they are large plants and give us lots of fruits.

Moisture: Top the MM with a good layer of mulch. You will be surprised at how long the MM will stay moist. You can probably take 3-day vacations without destroying the plants.   

tumtumsback wrote:...Boffer: I think I am scrapping the idea of the Wicking Beds. I am going to water from above straight up! For doing all of this work, I cannot risk the idea of not having adequate moisture. At the most, I will only be absent from the garden (vacation, etc.) for 3 days in a row at the most, at which time I can have a neighbor water the garden for me...

I think that's a better solution, too.    

Have you considered an automatic watering grid?  Something along this line:
https://squarefoot.forumotion.com/t13136-gravity-feed-irrigation-grid#130645

boffer wrote:

tumtumsback wrote:...Boffer: I think I am scrapping the idea of the Wicking Beds. I am going to water from above straight up! For doing all of this work, I cannot risk the idea of not having adequate moisture. At the most, I will only be absent from the garden (vacation, etc.) for 3 days in a row at the most, at which time I can have a neighbor water the garden for me...

I think that's a better solution, too.    

Have you considered an automatic watering grid?  Something along this line:
https://squarefoot.forumotion.com/t13136-gravity-feed-irrigation-grid#130645

A good layer of mulch atop the Mel's mix is very good for reducing moisture loss through evaporation.

Sanderson,

Wow -- mind blown with the top hat concept... I'm trying to think of how I would go about designing these top hats; maybe using something like Folgers coffee cans, hollowing out the bottom, and cutting them in half? How have you made top hats?

Also, when you say you have to clean out the roots, I assume that is after you harvest whatever out of one square and before you plant something new in that square?

The top hats are removable small boxes - you can make them 1x1, or any size that will fit in your existing box.  Fill up the small box with MM and for that little section you have 12" deep MM instead of just 6".  Here's a link to a pic from the Carrot Week thread showing Gwennifer's 1x2 top hat, or high rise in the middle for carrots.

https://servimg.com/view/16567771/152

GG

I'll take photos tomorrow morning of the top hat (looks like Gwennifer's) and 2 corner top hats make of left over 8" cedar fencing planks.

We used the idea below to extend limited resources and Mel's Mix in the garden last year... For what it's worth.

Last year I came across echonet.org.  On the site there was info for growing in urban and developing communities with little resources.

A suggestion was to take empty pop cans with a few holes punched in each and stuff them into old socks and or nylon stockings. This could then be used for filler in the growing medium with the cans holding on to water during heavy deluges as well as some air for the roots.  Additionally as the plants set roots into the medium, some of the root fiber will attach to the stockings holding the cans and aid in stabilizing the growing plant.

We had twelve inch and twenty four inch depths in our growing beds last year and by using the can in the sock laid down on the first two inches of growing medium followed by an additional 2 inches of MM followed by another layer of cans and socks and MM and so on with the top 4 inches of MM.

We grew: cantaloupe, cucumber, broccoli, cauliflower, tomatoes, beans, parsley, peppers, squash as well as hearty kiwi vines. We also continue to grow an apple tree in a 12 inch deep 4 foot square tabletop box for our SIGE (Special In Gods Eyes) group at St. Mathew's Church in Barrington, Illinois.

What we do is mostly proof of concept with a large dose of fun as most of our special needs group, (SIGE) experience gardening here for the first time.