# is there a down side to gravel in the bottom of a garden bed?



## cindy-e

I am trying to decide how to build my garden beds. They are going to be raised square foot garden beds. Around here, we don't get a lot of heat (stays in the 60's and 70's most of the summer), but we have good sun. However, I have noticed that drainage, mold, etc... can be a problem because it is really wet. So I thought that if I could put gravel down in the bottom it might help with both of those problems? I have not had good success with gardening here. I am used to gardening in the hot southern part of the country. Will the gravel help? Or is it a waste of time and money? 

Thanks,

Cindyc.


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## barefootflowers

I would think that as long as you weren't digging up the gravel when you planted or harvested then it should be fine. I'll be following this thread with interest because I will be planting in some raised beds with gravel at the bottom as well.


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## COSunflower

I have gravel in the bottom of mine as my raised bed area used to be a dog yard years ago. The gravel hasn't hurt a thing and seems to give good drainage to the beds.


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## where I want to

There are lots of things that help lighten soil to increase drainage that I think would be a lot less trouble than gravel. Sooner or later gravel will mix with the soil or the soil will sift into the gravel and plug it up anyway. And it will reduce the amount of growing soil you have unless the beds are really deep.
How wet is wet anyway? Standing water or just damp ground? I garden in the coastal redwood and it is very wet here most of the time except for those periods where it doesn't rain at all. The raised beds are enough to keep the root area from being waterlogged- I have some 6 inch high beds and some 12 inch. I do lighten the soil with vermiculite if I can afford it or rice hulls if I can't.
If it is an area that has standing water on it, I think I would work on ditching the water away or filling the area with soil to raise it above the water level.

Opps COSunflower- I posted at the same time- if you have tried it and found it good, I bow to your experience. But I do wonder if gravel in the bed would be as good as putting the bed over an area that has gravel on it all over.


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## Belfrybat

where I want to said:


> There are lots of things that help lighten soil to increase drainage that I think would be a lot less trouble than gravel. Sooner or later gravel will mix with the soil or the soil will sift into the gravel and plug it up anyway.


As long as you are using Mel's Mix for the SGG, you won't have a problem with drainage. Just put down a weed barrier or newspaper/ cardboard and build the beds on top of that. For more specific help on SFGs, go to their forum (just search "SFG forum"). If you are not using Mel's Mix, then I agree with the poster who said eventually the gravel will mix in with the soil unless you use a really heavy duty weed barrier.


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## motdaugrnds

I have researched this for hours upon hours because I don't want to bend over to harvest root crops; thus, I'm constructing raised beds in such a way that will negate this need.

My raised beds will be somewhat larger than yours. I plant on constructing actual rows by digging into the ground about 6"-1' and placing the sides/ends in there (extending all up about 2' from top of ground area. Then I will be placing #57 rock at least 6" at the bottom, cover that with part of the cloth I had left from repairing the mud puddle in my drive and replacing the garden soil (mixed with whatever would work well for what I'm planting). This means the bed, itself, will be at least 2 ft deep before it ever hits the rock, which should serve the bed well.


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## cindy-e

COSunflower said:


> I have gravel in the bottom of mine as my raised bed area used to be a dog yard years ago. The gravel hasn't hurt a thing and seems to give good drainage to the beds.


How long have you had gravel in those beds and how long have you been gardening in them, if you don't mind my asking? Good to hear that it is working for you.


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## mnn2501

rocks always rise. one of my gardens used to be a parking area for the old owners RV, we hauled out 6" of gravel but still had some, put down 6+ inches of soil and every year have some of teh gravel we missed rise to the top.


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## gobug

My former wooden raised beds were 12 inches deep, 4 ft wide 20 ft long. Before I placed the boxes I used a small tractor to scoop down 18 inches. I put a hose in and filled one box. It took 3 weeks for the water to be gone. I rented a post hole digger and went down another 3 feet about 70 times per box. I added a bunch of sand to the holes as I dug them. The drainage improved. Then I assembled the boxes in place and filled with good garden topsoil. After 2 years all my plants showed signs of poor drainage. I had to dig a trench through each box and out of garden, place a sock covered drainage pipe in the trench and refill the boxes. Ever after that the produce was much better.

Since your ground is wet, you might consider separating the box from the ground. Most annuals do not have deep roots, so you could put the boxes on tables. You would still have to watch moisture content in the soil and drainage.

good luck


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## COSunflower

The gravel under my beds is pea gravel. I've had the raised beds over them for 4 years now. We are in the high desert also. The beds are 12 in. high.


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## cindy-e

COSunflower said:


> The gravel under my beds is pea gravel. I've had the raised beds over them for 4 years now. We are in the high desert also. The beds are 12 in. high.


Does it raise back into the soil as is being suggested by others? If not, did you do anything special to keep it from doing that? Just curious as to how you make it work. 

Cindyc.


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## Paquebot

cindy-e said:


> Does it raise back into the soil as is being suggested by others? If not, did you do anything special to keep it from doing that? Just curious as to how you make it work.
> 
> Cindyc.


Gravel should not raise back up. That applies to larger stones and it's frost that does it. That said, gravel as a base under a raised bed works quite well. Just be sure to place enough soil over it so that spading or tilling doesn't ruin it.

Martin


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## COSunflower

No gravel has come up thru at all. I add compost to the top each fall - worm compost and shredded leaves. During the summer I put grass clippings between the rows to cut down on water evaporation. I don't spade the compost in, I just keep adding and let it break down itself. Once I get my camera going again I'll post photos in the spring and summer.


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## cindy-e

COSunflower said:


> No gravel has come up thru at all. I add compost to the top each fall - worm compost and shredded leaves. During the summer I put grass clippings between the rows to cut down on water evaporation. I don't spade the compost in, I just keep adding and let it break down itself. Once I get my camera going again I'll post photos in the spring and summer.


Thanks! I appreciate it!

Cindyc.


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