How do I deal with drainage on a raised bed?
I’m getting ready to make a raise planter bed for vegetables. My backyard is solid crabgrass, so I don’t want to have my new organic soil come in contact with my seriously crappy ground. I have found crabgrass roots thriving at over 3 feet deep. It has grown through brick and through stucco all the way up to my attic. I know for sure that if I don’t strongly seal the underside of my planter bed this parasitic weed will undo my first vegetable garden attempt (I have not attempted one before because of this problem and a raised bed seems to be the only solution). I refuse to use weedkiller in my yard because of my children and my dogs. My question is this;
How do I deal with the drainage or do I need to even worry about it?
My bed will be 24 inches tall, 4 feet wide, 10 feet long and made of wood planks. My current ideas to use thick black plastic underneath and wrapped up the sides. I have also thought of slanting a bottom floor made of plywood also covered with black plastic and a drain hole at the lowest point. Another idea I had was to put some crushed marble at the bottom ( like 5 inches thick) on top of the black plastic with three drain holes along each side but I’m sure the grass would just get in there in no time flat. How would you deal with the drainage problem?
Also if you have an idea for how to deal with the crabgrass that would be appreciated.
Thanks very much.
-Krane
I don’t know a lot about gardening, but could you have it raised up, like not touching the ground at all?
Liiike.. this?: http://www.instructables.com/id/Raised-Garden-Bed-on-legs/
| Published on February 7th, 2011 | | Posted by admin |
February 8th, 2011 at 1:32 am
mix some sand in with it… and why the plastic? if its for the weeds use a garden cover…make sure you cannot stick your finger through it….if its under the dirt thats not a good idea veggies most deff need the room to grow above ground as well as underground….sand is good for dirt that holds too much water
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February 8th, 2011 at 1:38 am
I don’t know a lot about gardening, but could you have it raised up, like not touching the ground at all?
Liiike.. this?: http://www.instructables.com/id/Raised-Garden-Bed-on-legs/
References :
February 8th, 2011 at 1:43 am
You probably have Bermuda grass in your yard not annual crab grass which does not germinate until spring. It can be controlled by herbicides such as Roundup applied in the spring or summer when the grass is growing actively. This herbicide is safe to use around children as long as you keep them out of the sprayed area until the grass has dried. As far as your drainage is concerned any technique that actually provides some drainage holes in the side would work just watch to see that the weedy grass does not enter through the holes or creep up over the planks. Pulling it out if you see it should help keep the bed free of the grass. Bermuda grass does seed redily so watching forit in your garden and pulling it berore it has a chance to get established is a must.
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February 8th, 2011 at 1:57 am
Well may be useful as a personal reference http://givingagift.info/336036/vegetable-garden
February 8th, 2011 at 2:22 am
Just edited, above post – this could be Bermuda grass? I’ll leave this in case you can use it.
I am really boggled about this form of crabgrass that grew upward to your attic. Crabgrass does not have interminable roots, but if you have such a crop as you say and soil in your attic, perhaps seed got in there (stuck to a spade?). Do you have some vining plant like kudzu making roots as well?
Crabgrass goes to seed and releases like 5000 seeds, 150,000 a season. All the surrounding plants will scatter seed on top no matter what you do underneath. If you have a yard full of plants you will be facing uncountable seeds, having a raised bed will not help you at all. You can dig down in your lawn soil two feet and put the good loam there, then weed the young crabgrass volunteers out with pliers. Use thick mulch. The volunteers need bare soil. If you have a raised bed, just do it for your own enjoyment, it is claimed land at least.
Just a cursory look at the web makes your decision to go non-toxic respectable. But you can drop the good loam right on top of the crabgrass, or dig, or double dig. If you make some barrier underneath it could get moldy and be a worse problem.
also:
ehow says corn gluten is a safe and effective natural alternative to synthetic pre-emergent herbicides
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