when can I plant after using cardboard as weed barrier under the bed?

I made a small 2x2 raised bed but as it said in the new book by mel, I only used 6 inches of soil (well more like 8...). I decided to use cardboard as the weed barrier. Then I realized... i made the bed on top of heavy clay soil that dries like a rock and doesn't even crack. a garden is supposed to have good drainage. especially when planting melons or pumpkins. 

1.i was planning on doing a melon or a pumpkin in that 2x2. thats 4 square feet. by eight inches. is that deep enough for the roots?

2.how is that supposed to drain?! first through cardboard, then through clay?! what was I thinking?! 

3.should I start over? maybe make a bed of rocks, then cardboard, then the bed? I'm so confused. also, wouldn't I have to wait until the cardboard deteriorates to be able to plant in it? because even if i did have good drainage under the bed, i was thinking the cardboard would prevent drainage.

oh my gosh. sorry for the post. it must should so obvious. i feel like I'm losing my mind over this for nothing. lol

DO NOT START OVER! It will be fine, just roll with it. The MM will assure proper drainage, and if adjustments need to be made, that can happen on the go. I think it will be more than OK

Scorpio Rising wrote:DO NOT START OVER!  It will be fine, just roll with it.  The MM will assure proper drainage, and if adjustments need to be made, that can happen on the go.  I think it will be more than OK

technically I just used miracle grow for vegetables mix. lol so i didn't use mels mix (if thats what mm stands for) so where will it drain to? are you sure it will drain?

OK, so did you put anything other than cardboard on the bottom of your box? If not, no worries!

I would recommend that you get your hands on "All New Square Foot Gardening" 2nd edition. Your library probably has it or can get it on loan. It will help you get a handle on the whole concept.

Oh yeah, Mel Bartholomew is the reason we do this, he invented SFG IN THE 70s. Get his book! He made it so simple and productive, it is almost unbelievable especially if you have ever done row gardening.

MM=Mel's mix

I did the same thing you did.  I have hard clay under the beds.  Then I put a thick layer of cardboard, then 8.5 inches of Mel's Mix.  the first year or two the water drained out the edges of the bed. Last time (I had to dig out roots) I put the cardboard down below the level of the ground and then watered it before I put in the mels mix and watched how it drained.  The water pooled on the cardboard because it was below the level of the surrounding clay.  So, unless it is properly shaped to allow the water to drain out the sides, the water will sit on the bottom of the bed until it is absorbed by the cardboard or drains out the sides or is wicked up by the mels mix.  I was a little worried about the drainage so I punched some holes in the cardboard to allow the water to slowly seep out the bottom.  Of course, the holes will also allow the tree roots back into the bed.

But, wouldn't the slow drainage help your beds retain moisture in arid Arizona ???  My bed is built with 9.5 inch sides.  Many people here use the 6+ inch of mels mix.  But because our summers are so hot I need as much depth as possible and a thick layer of mulch on top to help conserve the water.

@scorpio rising: 
No I didn't put anything other than cardboard under the box. But I did read both books cover to cover. I'm thinking checking it out at the library or just buying it since I would refer to it often would be a good idea. 

@yolos: 
You know, it's not like we drench the square foot garden anyways right? We just put enough water as Mel tells us. Like a scoop of warm water from a cup at the base of the plants. Plus your right about the whole arid thing in AZ. Perhaps it would be good. You know it's already in the nineties some days!? I'm not even sure we had a frost more than once this year! Not like Idaho where I came from! No rain like Texas where I grew up either.  Just dry and empty and hot.

Hi Lexilou! Welcome from Atlanta, GA. (Just saw your other thread/post...)

We have hard GA clay here and put a THICK layer of cardboard AND newspaper sandwiched between 2 layers of weed cloth on the bottom of our beds. It's been fine.

So, no worries!!

Can't wait to see what all you do.......

lexilou wrote:@yolos: 
You know, it's not like we drench the square foot garden anyways right? We just put enough water as Mel tells us. Like a scoop of warm water from a cup at the base of the plants. Plus your right about the whole arid thing in AZ. Perhaps it would be good. You know it's already in the nineties some days!? I'm not even sure we had a frost more than once this year! Not like Idaho where I came from! No rain like Texas where I grew up either.  Just dry and empty and hot.

Well, I have a feeling that in your climate the part about putting a cup of water at the base of the plant probably isn't going to work.  I think Cape Coddess uses that method so maybe she will chime in here.  In a shallow bed, the roots are not going straight down they are going down until they hit compacted soil/plastic/cardboard/weed cloth and then they are going to go lateral.  They will spread throughout the bed.  So just putting a cup of water at the base of the plant may not work.  Of course it depends whether you are growing things with shallow roots like lettuce or things with more of a root system like tomatoes.  Either way, good luck.

PS - I do drench the whole bed with water using a watering wand under the leaves of the plants to keep from getting the leaves wet.  I was supposed to put in drip irrigation this winter but unfortunately got called back into work from retirement and drip irrigation installation was put on hold.

I do bucket water but I have sandy soil under my cardboard, not clay, so it's a completely different animal. The clay base actually sounds good to me for a bit of water retention, as yolos mentions. If it were MM, personally I'd be real happy with the set up. It's the Miricle Grow soil that I know nada about. Best bet is to give it a try and see what happens. You can always make changes for next year...or even mid season.
Good luck.
CC

I use both the permanent drip irrigation and a hose wand. We are limited to 2 days of watering (the drip irrigation on timers) and the hose wand for the other 5 days. Did I really confess to that? Oh, and lots of chopped bedding straw mulch.

I'm in Texas. The forum help me addressed the heatwave by telling me to raise the bed to 12" and add mulch for water conservation and to keep the soil cool. it worked for me. I have heavy red clay beneath the box, but the earthworms and the soil food web has change the top 6 inches of clay to sandy loam.The cardboard will be great food for the soil food web community. Watermelon can grow a tap root 12-16 inches into the ground. When you think it not doing anything, it's concentrating the energy in growing the tap root, you may want to add 4 inches for depth.

oh thanks everybody! i feel a little more at ease, but also not. lol ill try to keep everyone posted about how it goes. Ill learn something from it for sure though.

Lexi, I have clay here too. Just not the baked kind, but still no drainage. The bed with MM does the draining for you, cardboard won't hurt a thing.