this is my plan....thanks

Your plants will only use about 6 inches of soil. So a good approach is to have your walls at least 8 inches high. I use the layering method; Layer 1) Carboard to prevent weeds and grass, 2) compost; 3) top soil, 4)Compost and manure, 5) Leaf mulch. I used landscape blocks for the walls. Here are pictures of one of my beds.

That is a good idea, but we both having bad backs, we need them just a hair higher, we are planning on placing a small "bench around the perimeter of each bed that way we can "sit" and not have to stoop so low to the ground, but I do like the "layering" of soil composites.

Thank you...

I agree with Charlie Boring's comments that shorter beds would be fine. The taller your raised beds are, the better they will drain and, while that sounds fine in principle, what it really means is that it can be almost impossibly hard to keep tall beds well-watered in a dry year. Beds raised that tall are essentially containers, albeit open-bottomed ones, and can require a lot of irrigation in the drier years.

Compost is good up to a point, but pure compost can dry out much too quickly in our hot summers. I have two separate and distinct garden areas. One is highly amended clay and those beds hold water very well. This area has a serious slope, so the raised beds vary in height above the ground, but most of them are only 4-8" above grade level. If I build them any taller than that, even they dry out too quickly. In the newer garden out back several hundred feet from the original garden, we have very sandy-silty soil in about 75% of that area and it drains so fast that I didn't build any raised beds at all back there. If I raised them above grade level, I don't think I could keep the soil moist enough in July and August of a dry year. Last year was my first year with that new garden and while it was a very hot, dry summer here, the plants at grade level did really well there. I think that area, which slopes strongly from the SE corner to the NW corner, also will drain enough in wet years. I don't have enough wet years to even worry about that anyhow--maybe 1 or 2 out of 10 years here where I live are wet enough to even worry about.

When I build raised beds, I don't import expensive soil and compost blends to fill the beds. I just work 6 to 8 to 10" of organic matter into the soil. Just by rototilling all that organic matter into the existing soil, your raise the soil above grade level. I just rototill a couple of inches of organic matter at a time into the soil, then add another couple inches, then another couple. What I use at any given time varies depending on what I have available, but I keep huge working compost piles so usually I am adding a lot of home-made compost. Back before herbicide residues in manure became such a big issue, I would use composted manure from a local ranch. I often compost old, spoiled hay for several years before adding it to soil as mostly decomposed hay/compost. I sometimes add purchased wood mulch chips and/or pine bark fines. I gather autumn leaves in huge amounts and chop them up by running over them with the lawn mower. I catch them in the mower's grass catcher and dump them onto beds in the fall. By spring they are decomposed and I can work them into the soil in the raised beds. Or, some years I just dump bags and bags of chopped-up leaves on top of my compost pile and mix them in with a pitch fork after snake season has ended. By spring, they are compost to add to beds.

There are some places you can buy bulk compost. Some cities sell it at a low price or give it free to residents of those cities. There's really no reason to try to fill raised beds with only compost. Remember that plants need the minerals found in soil too, and pure compost in our climate tends to dry out excessively and quickly. You also can buy soil/compost blends from bulk suppliers for a lot less than purchasing bagged amendments at a big box store.

By working to improve the soil you have, you improve the drainage and fertility of it, which is better for the plants that having pure compost in the beds raised above ground and then having their roots hit the native soil beneath the raised beds which would be a totally different density and tilth.

Dawn

Hi Joshua, last year was my first year to start gardening so I asked my hubby to build me a few raised beds. Although unnecessary, I wanted very tall beds for ease of gardening/harvest plus aesthetic reasons. I'm so happy with them, and super glad we went the direction we did! My beds (5) range from 12'x4' to 4'x4' but they are 24" deep! Keep in mind each are buried anywhere from 2"-7" for leveling purposes, and filled 6"-8" from the top. They are constructed of corrugated steel, cedar posts (inside the beds), and untreated lumber (across the top only). The big beds cost about $60 to build although we did have to haul in dirt to fill them which was the main expense. When choosing the materials/design, I was concerned the metal would heat up too much and not only affect the roots, but increase my watering requirements but it didn't. I only watered 4x the entire summer and my harvests were incredible all season so clearly the roots were all happy and healthy. I love gardening in these beds! The only problem I found was harvesting tomatoes at the top of 10ft plants ha! Maybe this year I'll top the plants a little earlier. :) Here are some picts of my garden. Good luck with your raised beds, you're going to love them!

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Alexis

Alexis, I love your raised beds. They are beautiful and I am sure you have every right to be pleased with them and with their performance last year. However, last year was a pretty wet year in your area wasn't it? It is easy to be pleased with a first-year garden in a year of plentiful rainfall. It will be interesting to see if they perform as well in a dry year. I find my garden is almost like a whole different garden in a very dry year compared to a very wet year and I have to do a lot of things differently to get the same results. Those are the sorts of things you cannot anticipate in advance---you just have to wait and see how the beds perform in a significantly drier year, and I speak from experience because I built some tall beds in Texas....and my experience with them there in dry years explains why I didn't build taller beds when we moved here.

I don't know how much your rainfall varies from year to year, but in the county where I live, the wettest year we have had since moving here in 1999 was about 54" of rain, and the driest was less than 19". It is those 19" and 22" and 25" rainfall years that would worry me with tall raised beds. Maybe you never have years there in your county which are that dry, but we certainly have them in mine.

If I could have anything I wanted without having to worry about how to keep tall beds watered, I'd love to build them all waist-high so I could plant, weed and harvest without bending over at all. My back is showing (or, maybe I should say feeling) the wear and tear of all the years of hard garden work. Ditto on harvesting from tall tomato plants though. One year my Tess's Land Race Currant plant grew like mad, and I first added a 2' tall extensions to the cage, so that the cage was 8' tall. Well, it seemed like a good idea at the time. The plant climbed to the top of the cage and then cascaded back down to the ground like a weeping willow. Once the cascading branches hit the ground, I cut them off so my feet wouldn't get tangled up in them. Since I had to use a ladder, in a sloping garden (!), to harvest, I learned that it was stupid to have a cage 8' tall, especially since I'm only 5'3". The next year, when Tess got above the top of the 6' tall cage, I just topped off the limbs so it would spread out instead of getting taller. It still was hard to harvest because it was so dense and thick, but at least I wasn't standing on a ladder to pick tiny currant tomatoes for hours on end.

If I was going to build a bed that tall above grade level in my typically hot and dry area, I'd likely build it hugelkultur style inside the bed so that I'd have the superior moisture-holding capability of the hugelkultur. That would help hold moisture in the dry years, but I am not sure what the result would be in the really wet years because it might hold too much moisture.

Dawn

Yes, you're right Dawn, last year was extra wet! Over 48" according to Mesonet, although my beds weren't built or filled with dirt until May 7th so my garden got about 36". Still a good amount of rain.. I'm sure in drier years, I'll be watering quite a bit more but looking at the last 14 years my area has gotten a minimum of 26" every year but two (03' & 05' got ~23") but on average we get ~35". Of course being a newbie, that doesn't mean too much to me.. Only years of gardening experience will teach me how much rain I need to hope for! :) Well, and great advice/knowledge from other gardeners like Dawn.. This year I have 15 large containers I'm growing in plus (1) 6" raised bed (4'x16') and two new in-ground beds I've been working on 4'x12' (adding lots of organic matter etc). It'll be fun to compare all the different areas/mediums I'm playing with this season. Just can't wait for the season to actually start!

Alexis, As you said, only time will tell how much more moisture your tall beds might need in a dry year. I don't think you'll have as many dry years there as I have down here. When we are expecting drought, I add a ton of wood chips to my beds, mixing it right into the soil....and I don't mean just pine bark fines, I mean big chunks of wood. I just go into the woodland in winter and look for rotting logs or branches and break them up and put them in the wheelbarrow and carry them back to my garden. I dig deeply under raised beds and bury them. When it is very dry, those chunks of wood will hold moisture a long time and the plant roots grow right into the wood seeking out that moisture.

As far as how much rain to hope for, my suggestion is to always hope for more, more, more! A garden here in OK (unless it sits on shallow soil over a high water table) almost always needs more rain here. I don't care how much rain I'm getting, I am greedy and keep hoping for more. There have been two years that we had too much rain at once and it caused problems for a month or two, but I still was glad we got the rain because it helped recharge our aquifer, which is important because our water co-op water comes from wells so we need for the wells to not run dry.

Even in a year when it looks like we'll end up with 40 or 50" of rain, I'm hoping for more and wondering what 60" would be like. (I'm not likely to ever see 60" of rain here, but that's my garden dream.)

You're going to have so much fun with all the new containers and your new beds.

The season has started, hasn't it? Well, except for that pesky ice, snow, sleet and cold air headed our way. Every day I carry my tomato plants outside to bask in the sun and I run my hands across the tops of them (it stimulates growth) and inhale the delicious aroma of tomato plants. It isn't really my favorite aroma, but in February it is good enough because at least I can get that gardening 'smell' even if the plants aren't actually in the garden yet.

The cool season is always challenging here and we find ourselves scrambling to protect plants from the wild weather variations, but when warm season gardening time is here, that's when the season truly begins for me because it is a lot more fun to stay outside all day when it isn't cold and windy. I work more sporadically when it still is the cold season, trying to cram the outside chores into the nicest part of each day.

Dawn

Your beds are beautiful!

Dawn, I saw your 78 and compared it to my 45 today. I finally started a few seeds this week but it doesn't feel much like gardening weather here. I planted Packman and it just sort of jumped up. I didn't even have the flat on the light shelf and discovered that I had half inch tall broccoli tonight, so quickly got it under lights. We have sleet and snow on the way, so my gardening will still be inside for awhile. I don't even have onions planted, so I am really going to be late.

These gardens are beautiful!

(Perusing some old discussions here). After carefully reading this thread, I'm wondering if increasing the % of clay in raised beds wd alleviate the drainage challenges. I have in mind the difficulty mentioned of keeping raised beds watered sufficiently in dry years. I'm considering adding a fairly tall raised bed to my brother's place, but the watering difficulty mentioned here gave me pause. Then I thought of the black gumbo ("blackland prairie" clay) I used to struggle with. I know a materials place that sells a quite clayey soil, and there's a lot on site anyway. Wd not a combination of hugelkultur and the right percentage of clay in the bed's soil prevent the need for such watering?

The right combination of clayey soil and hugelkultur could prevent the need for such watering. The dilemma you face is to find exactly the right amount that will function in a year when you get 50-60" of rainfall (rare here in southern OK, I know) and also in a year when you get 15-25" of rain. You'd just have to try it and then fine tune your material in the raised bed as you learned from experience just how much moisture it holds as well as how well it does or doesn't drain.

I have raised beds filled with improved red clay that has had organic matter added it to for about 15 years now. They hold moisture really well in wet years, and moderately well in dry years. However, in an exceptionally wet period (2007 comes to mind) they still can stay waterlogged for far too long. Luckily, years like 2007 are few and far between. In an exceptionally dry year like 2011, they don't hold water well enough long enough, but then, years like 2011 are rare too. We hope.

We have a few areas with sandy soil, but mostly have dense red clay. I've always thought that if I could take a giant blender and mix together our sandy-silty areas with our clay soil areas, we'd have a beautiful clayey loam.

Thanks Dawn. My overriding concern has been adequate water retention, but I'm seeing now that you can go too far and drown the plants. One year, it's been almost 10 years ago I think, we had so much continual rain that some great fruit trees at my brother's died. He had that blackland prairie soil and it just could not drain off the water.

Charles

I have a shallow h-kulture beneath a planter that receives about 6-7 hours of sun before the house shades. I was not able to throw money at this planter, so I filled it with yard dirt (compact clay loam), hard clay, and some sandy soil from beneath a naturally mulched fence line. It took me a long time to get a good soil from a combination of areas. I can appreciate buying and hauling in decent soil! I broke down the clay by hand and mixed it all together. At the time I had no amendments to add. I really didn't know what I was doing, but going by what I read about what soil should be. Anything and everything likes to grow in that planter. My back went out after that. I neglected it. Things grew and they grew in the drought and they volunteered the next season, too, without any help from me.

4 years later it is becoming quite sandy atop and the soil looks spent. Only now am I considering refilling it. Carrots, parsley, echinacea and radishes, are happily growing there, right now. Even though the surface is sandy and the drainage is very fast, the moisture is sticking around in the 'pit' beneath it. It's kinda strange to see these beautiful green plants standing in what looks like dead soil.

By the way the soil is sinking, I'm guessing the wood beneath has already rotted away (because it was shallow), but the soil beneath all is probably very very rich. At least, that's what the plants are telling me.

bon

Bon,

That's very encouraging. My first hugelkultur project was last spring so the jury's still out, but if a bed will go on for 4 years or more I'll be very pleased.

We had a heavy duty trencher/digger on site for plumbing work and I took advantage of that. Figured out how to use it and buried lots of 5- or 6- inch logs from fallen dead trees out back. Put em about 2-feet down beneath a section of the new garden. Added some oak leaves, leonardite and zeolite while I was at it. We'll see how it all turns out.

Charles

Charles, You're welcome. It might have been exactly 10 years ago. I remember 2004 as a really, really wet year, especially in April-June, when our mesonet station recorded around 18" of rain. We were having a big detached garage built, and every day they tried to pour concrete in June, a flood of rain would come. We got a foot of rain that month, and some plants did waterlog and die.

I did hugelkultur in Fort Worth in the 1980s (didn't know what I was doing had a name, but learned later on that ihugelkultur is what I was doing) to improve black gumbo clay. Worked great. I haven't used it as much here. We are too rural, too close to the river and too snakey. Anything that resembles an above-ground brush pile fills up with undesirable creatures, so I'm scared to work around brush piles on a daily basis. I do use some hugelkultur materials to fill in trenchs, depressions, eroded sloping spots, etc. As the material decomposes, I scatter wildflower seeds over it and that low spot in the land is healed and thriving. Our land slopes and has many eroded areas, so I just work on them one at a time.

I may have to bury hugelkultur materials in trenches dug into the new (new last year) garden out back in order to get anything to grow back there. The plants did well back there last year, but with more irrigation than I liked. This year that ground is as hard as concrete---even the sandy portions of it. Right now, I'm using hugelkultur to fill in the lily pond that eventually became the water moccasin pond. It was pretty big and several feet deep, so filling it in, log by log and limb by limb may take all summer. We've already had trouble with skunks and snakes getting into that pile of stuff and trying to live there, but once it is filled in enough and I get soil added, that nonsense will stop.

Dawn