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ElizabethB
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Location: Lafayette, LA

Re: Sunken Garden Beds

DITTO RBG on selecting region specific, drought tolerant varieties of vegetables.

SIL waters her table top boxes with a watering can. Watering only the base of the plants. Her "mile high" climate is arid, has persistent winds and high temperatures in the summer can be higher than in the deep south. SIL is a scientist (as in 2 PHD's and multiple certifications) and an avid preservationist. She is very pleased with low water usage and ease of working her vegetable garden.

She does use Mel's Mix. She maintains a compost bin and purchases peat and horticultural vermiculite when needed.

DO get into composting.

I had a kind of crazy thought. :!:

Typical SFG boxes are 6" - 8" deep. The bottom is lined with contractor grade, woven, landscape cloth (not the cheap felt like stuff you find at big box stores)

Dig down no more than 1" into your native clay soil. Line and build your boxes deeper - like 12". You will create a "water pan" beneath your boxes. Not so deep that it retains huge amounts of water.

:eek: Crazy but that is what you get when a gardener is presented with a problem!

I am really looking forward to hearing more from you. Keep us updated on your decisions and your progress.

Good luck
Elizabeth - or Your Majesty

Living and growing in Lafayette, La.

When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant. ~Author Unknown

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ElizabethB
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Location: Lafayette, LA

Re: Sunken Garden Beds

-wall- I forgot :!:

Use raised beds and MULCH :!:

Pine straw is the absolute best for water retention and weed control.

You do need a thick layer to start - 12". Pat it down around your plants then let it compact with time. The needles twine together creating a very effective weed barrier while allowing water to flow through and at the same time slowing down the evaporation process.

It decomposes slowly minimizing replenishment.

Contrary to popular belief it does not have negative impact on your soil pH. Pine straw is the ONLY mulch I use and I do have periodic soil test done.
Elizabeth - or Your Majesty

Living and growing in Lafayette, La.

When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant. ~Author Unknown

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rainbowgardener
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Location: TN/GA 7b

Re: Sunken Garden Beds

Absolutely second that about the importance of mulch, one of the main purposes of which is to conserve soil moisture. Very ingenious, Elizabeth's idea of creating a water reservoir. Turn your whole bed in to like a giant self watering container, and yet nothing is standing in water!

Re the mulch for veggies I like to do a green/brown mulch (where "green" and "brown" are used as in Composting, see the composting basics threads at the top of the Compost Forum). So you want nitrogen rich materials like grass clippings, pulled weeds and carbon rich materials like the pine straw, regular straw, fall leaves, shredded paper, mixed or layered. Make a good thick layer of mulch, like 4" or so of it and renew when it starts breaking down and disappearing. The green/brown mix makes a more complete compost for feeding the soil when it breaks down.
Twitter account I manage for local Sierra Club: https://twitter.com/CherokeeGroupSC Facebook page I manage for them: https://www.facebook.com/groups/65310596576/ Come and find me and lots of great information, inspiration

Dawn R
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Location: Southern California 8B

Re: Sunken Garden Beds

Thanks for the wonderful ideas. I try to choose more regionally appropriate species of veggies and sometimes omit water hogs. I try to strike a balance between my personal wants and the regional realities. Thank you SO MUCH for the link. I do find it hard to tell which veggies are a good idea around here.

Where mulch is concerned: I have had the WORST luck with pests in my mulch. House flies in particular, but also some kind of still unknown pest (I suspect cucumber beetles). I tried and pulled up 3 separate types of mulch and every time one went down the flies and pests returned in droves. (Bye bye baby zucchinis)

The sad reality of our dry heat is that the bugs are drawn to any moist space like mulch and there are few of them. I even have a garden lizzard living in the bush 2 feet from the garden who comes to snack on the bugs. However, Mr. Tail and my fly trap are not nearly enough to keep the flies drawn to the mulch in check. I love the idea of mulching and I do keep it under my orange tree, but sadly it is no longer going in my garden. If I mulch my garden, our entire back yard is unlivable and they find way into our home.

Composting on the other hand, I am giving thought to. I know there are supposed to be pest-free ways to compost and I love the idea. I do have a worm tower feeding my garden, but it can only take so much. I will have to figure out a compost situation soon.

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rainbowgardener
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Re: Sunken Garden Beds

wow, my climate is so different, I don't think of things like that. But what kind of mulch were you using? The word covers a lot of different possibilities.
Twitter account I manage for local Sierra Club: https://twitter.com/CherokeeGroupSC Facebook page I manage for them: https://www.facebook.com/groups/65310596576/ Come and find me and lots of great information, inspiration

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digitS'
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Location: ID/Wa! border

Re: Sunken Garden Beds

This may be of help.

I live in a semi-arid environment. There is less than 20 inches of precipitation, annually. Most of that falls during the winter months. It isn't really unusual to have no measurable rain during a summer month.

Rain or irrigation water moves quickly beyond the reach of most garden plants because there are hundreds of feet of glacial till beneath them - gravel. Adequate water for a compost pile can be a problem. For this reason, I've found that semi-subterranean compost piles are best.

They aren't that much work. I dig out an area the depth of a shovel blade, about 8". Since most of my gardens are in beds, I have often used the beds. So, the "trench" is the width of a bed. The trench is filled with compostables and the soil is returned as a layer near the middle and as a cap. It all decays quickly during the heat of summer.

If things were just left for complete decomposition, the soil would be close to being level again. If I was to move some of the soil elsewhere, instead of returning it all to the mix of compostables, the result would be a sunken bed.

Steve
We are each other's harvest; we are each other's business; we are each other's magnitude and bond. ~ Gwendolyn Brooks

imafan26
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Location: hawaii, zone 12a 587 ft elev.

Re: Sunken Garden Beds

True in sandy soils, unless you add a lot of organic matter, water does not stick around for long.

But if you have clay and amend that with lots of organic matter, water will stick around longer.

In the keyhole garden, the compost bin in the center, not only provides nutrients, but also acts as a reservoir to hold and distribute water to the rest of the garden.

If you want to grow plants that need more water and you want to get the most mileage from the water you have then the SIP or earth box (self watering containers) do work very well. Watering with drip irrigation or subterranean watering with watering tubes are also possibilities. If you water the root zone the water does not evaporate as fast as when it watered on the surface. Mulching well also will help retain water in the garden longer.

It might be worth trying out a few things as some things will work better on some plants than others. I.e. tomatoes in earth boxes.
Happy gardening in Hawaii. Gardens are where people grow.

gingergardener15
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Re: Sunken Garden Beds

There are many ways to be more water conscious. I haven't really considered a sunken bed, but there are many other things I do that help conserve water like use a rain barrel, gray water, and drip irrigation. Here is a link to an article that gives some more tips on how to conserve water in the garden:
https://gardendripsystem.com/15-things-y ... se-garden/
Hope this helps! :wink:

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