Bottoms on Raised Beds

[SimpleTechGuy]

Hey everyone, newbie to the community here. I'm starting up a community garden to support local charities and the location is going to be on top of an old dump site so I'm a bit worried about contamination and have decided to use raised beds. My concern is that if I don't put a bottom on the beds the roots might get into the soil beneath the beds. I've thought about putting some type of bottom on the beds but then I'm worried the roots might not have enough room to grow. Going to use 2x12 lumber and fill 10" of organic veggie mix soil from local landscaper...

Just wondering if anyone here has a similar experience and or suggestions?

Thanks for all your help...

 

[Chuck]

A couple of thoughts on this. What was dumped there? Any toxic materials or chemicals? If you do put an impervious bottom to the bed what will this do as far as drainage is concerned? I think I would first test the soil before going to all of the expense of building raised beds with lumber. If the soil tests OK then all you have to do is just incorporate the soil you were going to buy anyway. If the soil tests are not OK I wouldn't have a garden there in the first place.

 

[SimpleTechGuy]

Thanks Chuck, great thought in regards to drainage. I hadn't considered that yet, I wanted to do a soil test and probably still will but it's getting late and I was hoping to get some plants in the ground 4 the spring. as far as I know so we will test you can take a couple of weeks or more before we get the results. The dump site was about thirty years ago and I think it was just construction debris but I don't have any proof and I'm unsure as to whether or not there were any toxic chemicals in their.

 

[Chuck]

Thanks Chuck, great thought in regards to drainage. I hadn't considered that yet, I wanted to do a soil test and probably still will but it's getting late and I was hoping to get some plants in the ground 4 the spring. as far as I know so we will test you can take a couple of weeks or more before we get the results. The dump site was about thirty years ago and I think it was just construction debris but I don't have any proof and I'm unsure as to whether or not there were any toxic chemicals in their.

Why don't you dig a few test holes? Construction debris are normally harmless to humans but some, such as asbestos are not. And some such as asbestos roofing materials are harmful to plants and humans. By digging a few holes you can probably determine what is buried there as shingles and insulation take a LONG time to break down.

 

[SimpleTechGuy]

Why don't you dig a few test holes? Construction debris are normally harmless to humans but some, such as asbestos are not. And some such as asbestos roofing materials are harmful to plants and humans. By digging a few holes you can probably determine what is buried there as shingles and insulation take a LONG time to break down.

I dug around a bit and it seems the debris is about 30 or 40 feet away from the area where I want to plant.. There may be some deeper than I can dig, but do you think the debris could affect the soil so far away?

 

[Chuck]

I dug around a bit and it seems the debris is about 30 or 40 feet away from the area where I want to plant.. There may be some deeper than I can dig, but do you think the debris could affect the soil so far away?

Is it uphill or downhill from the garden. Being 30 ft away it is doubtful that construction debris would leach that far either way. I think you are safe but do some tests anyway just to make sure

 

[SimpleTechGuy]

It's uphill from the debris... I'll get the soil tests just to be safe but for now I think I'll go ahead and plant without putting anything on the bottom. Thanks for your suggestions!!

 

[InvasiveCreeper]

Going to use 2x12 lumber ...

All standard lumber is treated, so that is not something I would use, especially if you are planting anything you might want to eat. Natural rock, natural stone, or stone slabs might be better. Organic hemp fabric is an option for a liner.

I am part German, and in my opinion hugelkultur beds work well also.

I personally would find a better spot than an old dump site, as you don't know what types of chemicals, sewage, rubbish, etc, has been dumped there over time.

 

[SimpleTechGuy]

All standard lumber is treated, so that is not something I would use,

Wow, I didn't think about that either, thanks for the suggestion. I spoke with some of our local gardeners and this is what they use so I assumed it would be ok. Did some poking around the internet and it sounds like some of the wood can even have arsenic in it.. Thanks so much for pointing this out, I've got a pretty big decision to make now.

I am part German, and in my opinion hugelkultur beds work well also.

Never heard of hugelkultur, just looked it up on the internet.. Seems like fun!!!

 

[InvasiveCreeper]

Simple Tech Guy,

You're welcome.

Good luck with your community garden.