Raised bed above lead contaminaed soil

Hi all, what a great forum. I'm a complete novice. Came across the (older version of the) book a few months ago. I built a 4' x 4' frame for a 12" raised bed last weekend. I also bought the material to make Mel's Mix.

I'm going to grow vegetables. I'm doing a raised bed because the soil in my neighborhood in Brooklyn tests high for lead contamination. I want to put a barrier between the Mix and the soil that's already in the ground to prevent the lead from leeching up into the mix. I'm thinking of using some kind of plastic sheeting (not garden fabric since it's porous). Maybe even heavy duty contractor plastic bags.

Two questions:

- Should I put a layer of gravel on top of the plastic before I put the mix in to help with drainage?

- Will the mix work as it should with a plastic barrier between it and the natural soil?

Forgive me if answers to these questions are found elsewhere. I did a search and didn't find them.

Thanks!

You need some tabletop beds...search on our forum for TT or table top and check out what you find.

It's basically a raised bed just raised up higher, with a plywood bottom, holes drilled for drainage. You can put it up on cinder blocks, bricks, or legs. It doesn't have to be way tall....just up off the ground. That will give you the drainage you NEED and the peace of mind you are seeking from the soil.

Boffer is our in house TT specialist...I am sure he will chime in.

Good to have ya!

When you get a chance, pick up a copy of the All New Square Foot Gardening book. Mel has completely revamped the process. It is now a lot easier.

If I were you and if I knew that the site I wanted to put my garden on was contaminated I'd use table top sfg beds. This is something else that is new in the system.

For a TT SFG all you need to do is get the box up off the ground and put a bottom on it with drainage holes.

If you do a search you'll find sever topics in the TT SFG.

and YES to what they said. I would put a wooden bottom in the bottom of the boxes and set them on cinder blocks, bricks, or something, just to get it up off the ground. Even with plastic under it, I would be anxious about it. But it is so easy to raise it up and then you don't have to worry about it.

You also can make it only six inches deep except for where you want to plant things like potatoes or carrots. That will cut down on materials and expense for you.

Best of luck to you.

Gwynn

See that is why we have Regional Hosts...

I am sorry I didn't give you a proper !!!

So glad to have you!

Hi middlemamma, OH, and dizzy. Thanks so much for your quick replies. Glad to be here. As others have noted, it's so much more friendly than a certain other popular gardening forum.

Okay, I've ordered a copy of the new edition. And I've poked around the site and read about some of the "improvements." (Looks like I'm going to be returning some bags of sand, a bunch of peat moss, two bags of gravel, a bag of lime and some compost! Well, maybe I'll keep the compost.)

The wood bottom sounds like just what I need. I didn't like the idea of using the plastic barrier anyway.

Can you grow tomatoes and cucumbers in 6"?

Thanks again.

CatchAFire

It is sad to hear about lead contamination, but you can rise above it.

Here is a link to Boffer's truly informative post on building Table Top Square Foot Gardens. .BUILD A TABLE TOP
To avoid the lead contamination, you might need to raise your bed just with bricks or cinder blocks at each corner and maybe in the middle. However, once you have tried a Table Top built at hip or waist height, you will be amazed at how easy your gardening will be.

Glad to have you here and please keep us updated on your progress. We pictures too.

CatchAFire wrote:Hi middlemamma, OH, and dizzy. Thanks so much for your quick replies. Glad to be here. As others have noted, it's so much more friendly than a certain other popular gardening forum.

Okay, I've ordered a copy of the new edition. And I've poked around the site and read about some of the "improvements." (Looks like I'm going to be returning some bags of sand, a bunch of peat moss, two bags of gravel, a bag of lime and some compost! Well, maybe I'll keep the compost.)

The wood bottom sounds like just what I need. I didn't like the idea of using the plastic barrier anyway.

Can you grow tomatoes and cucumbers in 6"?

Thanks again.

Howdy CatchAFire:

Keep your compost and peat moss. The rest can go back to the garden center!

Under the ALL NEW Square Foot Gardening program you will need what we lovingly call Mel's Mix. Mel's Mix is 1/3 peat moss, 1/3 vermiculite and 1/3 blended compost. Blended compost consists of a mixture of at least 5 different sources of compost. Normally you will need to purchase the different types and blend them yourself. The types of compost can be leaf, grass, horse manure, goat, shrimp, seaweed, cow, zoo poo, or just about anything that you can find. About the only thing that I would not put in my garden are human or any composted manures that came from meat eating animals such as Lions, Tigers, or Bears - OH MY.

Another way to get Mel's Mix is to purchase ready made Mel's Mix. Some small garden centers as well as the big box stores will have it. On the East Coast of the U.S. it is made by a company out of Connecticut under license from the Square Foot Gardening Foundation.

And yes, any vegetable can be grown in only six inches of Mel's Mix including tomatoes, cucumbers, corn, beans, turnip, radish, and anything that has a root under six inches long. If you want to grow long carrots use a deeper box or build a top hat box to sit on top of a regular Square Foot Gardening raised bed.

God Bless, Ward and Mary.

to SFG and the forum.

I read an article about neighborhoods like yours, so sad. Unfortunatley in big cities this is not uncommon. However the solution truly is SFG. Check out boffers TTSFG (Table Top SFG) and take WardenWakes advice about the MM. Hopefull boffer will sign in in a bit and give even more advice, he has added heating coils to his TTSFG's and is growing earlier and later than others in his area, the Pacific NW. Keep us posted and let us know if we can help.

I want to chime in here. Since you have already built a 12" high bed, you might want to keep some of the gravel to fill up the bottom of the bed. You only need 6" of mels mix to grow in. No need to fill all that space with the good stuff. Unless you used 6" planks stacked together and can take it apart and have 2 beds instead of 1. . You just put a layer of landscape fabric between the MM and the gravel.

I use tabletops because of bad knees, and it has made my gardening life so much easier.


And welcome.


Kay