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mister_gin

Raised vegetable bed questions

mister_gin
18 years ago

I'm both new to Arizona and gardening at the same time. I picked up some 2x8's to build a 4'x10' box which I was originally going to set into the ground but now I believe I want to go with a raised bed. I wish I would have bought 2x10's or even 12's but I can replace or add on later if needed. I've decided to take over some of the kid's pea gravel play area so it'll be easy to plop it down there. I feel it's a good spot since the bed will be running north south and set against an east facing wall. Anyway, on to my questions:

1) What kind of soil do you typically find in Arizona? I know our house was built on farmland but no telling what the builder removed or added.

2) Is it best to dig down I few inches and mix this in with the new that I will be adding? I will be planting some carrots but I will probably go with a shorter variety.

3) What is best to fill in the raised bed? I was thinking about getting a 1/2-3/4 ton of screened top soil (about 4" depth) and add a few inches of compost. Does this sound about right?

4) Regarding the compost. I've got a few of those big blue bags of compost from Lowes. Is this the correct stuff to use? I feel this stuff is probably best if used on top of the soil and not mixed into it. It seems more course than the smaller bags of compost I've seen.

5) Finally should I add anything like Vermiculite or steer manure to the mix?

Sorry for all the newbie questions. I see a lot of raised bed posts but I didn't know if there was anything in particular that should be done for the desert climate. I would like to have all this set up in time for the fall planting.

Thanks,

Wade

Comments (40)

  • jkochan
    18 years ago

    Welcome to Arizona where you can cook your vegetables while they grow! YouÂre going to get some great advice here on GW from some really nice people. The soil here is heavy clay in my area (Chandler) but may be different where you are. No matter what soil you end up with, the general rule is amend, amend, and amend. I grow in 6" raised beds. I put together four, 4 x 7 foot frames. I put them on top of the existing soil, added six cubic feet of compost to each bed and roto-tilled it in. I have added 3 cubic feet of compost each year for the past 5 years. By the time youÂre done roto-tilling every thing will be light and fluffy but as you water it will start to compress. So far I haven't had to increase the bed height because the compost keeps breaking down and reduces the volume. For starting a new bed I used the Kellogg mulch because it was a very fine screen and it really helped break up my soil. I try to stay away from composted forest mulch because it has a lot of wood that is not completely broken down and that can rob your soil of Nitrogen. Adding manure is a plus, but remember, we have a fall growing season here and can grow some crops right through winter. So if you want to start a fall garden get well composted manure and get in turned in as early as you can. Well that's my 2 cents worth. Once again welcome to AZ and Arizona Gardening!

    Here is a link that might be useful: Jim's Veggies 2005

  • Pagancat
    18 years ago

    Hi Wade, welcome! Hope we hear from you often.

    Jim grows a lot more veggies than I do, so he's a much better resource than I am. I have created raised beds in my yard, but mainly because I have a Bermuda grass lawn that simply overruns anything else. I used old RR ties (where most of the creosote had gone away; there's a reason they use them on tracks!) and lined the bottom of the bed with a few layers of cardboard and newspaper. The soil I used was mostly native - had I been growing veggies, I would have used my own compost, but didn't need it for the natives in these beds.

    One of the factors that you need to cope with in our soils, no matter the consistency, is the alkalinity. Even if you acidify your soils, you are watering with rather alkaline water (unless you are using rainwater) that will sooner or later cut the acidity that you gained via organics, sulfur or any of the other methods. This is not to say that you shouldn't use any of thoe methods, *especially* compost as it has many other properties that are helpful. It just means that this is something that will always be an issue as long as you aren't planting desert or desert adapted plants; most of our favorite fruits and vegetables are not.

    I strongly suggest perusing our FAQ sections for info on books about desert gardening as well as watering, etc. There's a lot of collective info in there that you'll probably find helpful at some point or another.

    Welcome again!

  • DrynDusty
    18 years ago

    In real xeriscape gardens, the preferred method is sunken gardens, to utilize more fully any rainfall. Raised beds are more exposed, and use more water. Apparently the ancient Native American gardeners used what is called "waffle gardens," with raised walkways. Just a thought. Norm

  • mister_gin
    Original Author
    18 years ago

    Thanks for the welcome.

    Jim, I am in Chandler as well. I don't know why my zip code came up as zone 8. I thought I was more in zone 9 than anything else.

    Since I'm using 2x8's I feel I should add about 6" of material. I'd like to have the level inside the bed to be within an inch of the top of the lumber. I'll need roughly 21ft^3 of material to do this. This is why I wanted to bring in some top soil as I thought is would be better than using 20+ 1ft^3 bags of compost and manure. I thought I had read that you should have a certain ratio of compost to dirt. Can't remember what the exact ratio is right now. Is it okay to use all compost for these types of gardens?

    Pagancat,

    I just checked out a few gardening books from the library. One is "Desert gardening: Fruits and Vegetables" by George Brookbank and the other is "Month by Month Gardening in the Desert Southwest" by Mary Irish. Hopefully these will help me get started.

    I hope to get all of this setup over weekend. I'll just need to run a temporary irrigation system over to the bed and I should be ready to go.

    Thanks,
    Wade

  • jkochan
    18 years ago

    Wade,
    You can buy the Kellogg mulch in bulk and I'm sure other brands too if you check with the nurseries.This can save you some dollars. If you have the heavy clay like I do, you won't need top soil. The clay holds water very well and you just need to break it up. Just keep adding the compost and tilling in. The bed level will start to rise and it will be really good soil. When you buy topsoil, you can't always be sure of what you getting and what's in it. Remember, when you grow in raised beds, itÂs a two edged sword. The soil warms faster in the spring, but heats up more and looses more water during the summer especially with wood frames, and cools quicker in the winter. You want to have the roots go down in the soil where itÂs cooler or warmer depending on the time of year. The top three inches of my frames are to allow for watering wells (somewhat like D&D pointed out) and for 3" Â 4" of mulch to keep down the weeds and reduce moisture loss. If your bed is 4 x 10 x 8 you have about 26.6 cubic feet of planting area. If you have good clean clay, I would add about 13 to 15 Cu/ft of compost and start tilling it in to your top 6" of soil and see where the levels end up. YouÂll be surprised at just how much it takes to break up our soils out here. Do a percolation. test to check your soilÂs drainage. (See FAQS) With monsoon rains on their way (we hope), if you donÂt allow for our occasional frog stranglers, all your nice new soil may just float way! If youÂre going to be growing in just one bed, itÂs difficult to rotate your crops from one year to the next, so you need to allow for as much fresh nutrients and material as possible and, (not to wish illÂ) if you manage to get a fungus or other soil problem there is less material to change or treat. If you ever find that you start having too much soil in your beds, just transfer it to some of your other plants and trees.

  • mister_gin
    Original Author
    18 years ago

    Jim,

    I think I'll take your advice and keep the soil within 3" of the top of the lumber. This way I can pick up less material now and add more as needed later on. Unfortunately, I'm only going to have the one bed for now, so I consider this to be my starter bed. As I stated earlier I'm placing this in a 20'x25' pea gravel area that was originally designated as the kids playground area. If this first bed works out then I can easily add two better constructed beds east of the first one and then go back and replace the first one if I want to. I have room for three 4'x10' beds with a 2 1/2-3' pea gravel walkway between each one. The pea gravel isn't too bad to walk on.

    Thanks again,
    Wade

  • Pudgy
    18 years ago

    I don't have desert conditions, but the heat during
    the summer shuts down the growing of almost any veggies
    and most other plants (its just too darn hot)...
    I use raised beds during this Fall's ***hot*** (80-100)
    degs from Sept to end of Nov. I would recommend in the
    Plano TX area to not be afraid of raised beds, they work
    and quickly if you buy the compost from Plano Pure, the
    city composting organics reclaimation program. I now
    do all my own composting, with about 40 cubic yards cooking
    for this Spring veggie garden and returfing projects.
    The raised bed solution for me on top of the clay soil
    that appears to be akaline around here was the smartest
    and cheapest solution. I took old untreated fencing (cedar)
    that I was going to replace anyway (fence needs to be
    redone), and made a 9' x 15' x 5.5" bed. Math told me
    that 1.5 cubic yards was what I should get to fill it.
    I watered, hand turned to a spade shovel depth (7-8") the
    sod, and immediately put on the compost. Made rows and
    seeded (now I reseed with a more broadcast approach), and
    planted, as well as putting on hammered/shredded ash that
    I found down at my neighbors house that had 3 trees removed
    that same week.

    So, raised beds, compost/ing, mulch (shredded hardwood
    is a good material), compatible gardening techniques
    (plants/ing that are happy together and help avoid bugs
    and disease) have worked for me well in the past 4 months.
    I hope you find the same sort of success I have had, it
    has so far been a wonderful and fruitful experience.

    Pudgy

  • az_pamperedchef
    14 years ago

    Wade,

    Sorry to raise a long dead thread but I was curious how your raised beds turned out? I've been thinking of making some, but it seems like so much work and I truly am a novice. I think I can be convinced if I see success with others!

    Thanks.

  • mister_gin
    Original Author
    14 years ago

    az_pamperedchef,

    My first raised bed, which was built after this post, has been terrific. It's a north south bed that gets good afternoon shade. However lately it's getting too shaded by a fast growing tex ash tree, so I haven't been fully utilizing it. I plan to relocate it this fall. I'm thinking about going with blocks instead of wood next time around. I don't know if blocks are ideal to use here.

    I have built a second east west bed that I am fully utilizing now. Here soon I will have to cover it as it gets more sun than my first bed. I have also started to utilize a section of my yard for full sun veggies like okra and watermelon. I like the raised beds but they do have a tendency to dry out even when mulched. The drying out occurs the most around the perimeter where the sun beats down on the exposed wood.

    I started to make my own compost so I have little need to buy it anymore. I did have to buy a lot when I started out though. I still buy the occasional bag of composted manure for my watermelon areas.

  • greenthumbjeff
    14 years ago

    I am currently using a raised bed garden, about 10' x 5' and have built many successful gardens for others. The key is preparing the right soil and ensuring the plants receive enough water (through efficient drip irrigation).

  • mangledmind
    14 years ago

    az_pamperedchef,

    We have 3'x6'x1' raised beds (9 total and growing), 5 front and 4 back yard. Too much money to remove all the "landscape rock", so we installed raised beds, the rock bottoms allow for good drainage.

    GroWell Organics has decent soil for raised beds, for a very good price, but do check the soil as you place it into the beds, it is not sifted very well. We have found paint covered wood, metal springs, plastic and glass. "Amend" from Home Depot or Lowes is great stuff as well, approx $6 a bag, mixed with a bag of good potting soil and your garden will flourish.

    I'll take pictures tomorrow (Sunday 4/25/10) and try to post them. We are adding more beds to the front, so you can get an idea of what we have and how we are prepping the sites and beds.

    mister_gin,

    I am hesitant about using blocks, I think they will absorb too much heat and the soil might "steam" the root system of my veggies.

    I have noticed the same thing with dry edges of my beds, they tend to pull away from the sides when dry. But dig a little bit from the sides and there's moisture. One neat idea I have found on the web is those boxes with 2x4 or 2x6 nailed on top to add seating/kneeling areas, this may provide shade to the edges.

    We just started a compost bin, 4'x4'x4'. First one ever, wish us luck :)

    greenthumbjeff,

    We have a drip kit, just too busy to install the rest of the PVC to the garden. But we are at a point now that it has to go in before any more beds.

  • mangledmind
    14 years ago

    az_pamperedchef,

    Sorry no pics. All pictures have to be reduced to 61k or less, only allowed to add one picture per post and ONLY in the Gallery area of this forum, so cannot post as follow up. Way too complicated to post pictures here on garden web. :(

  • az_pamperedchef
    14 years ago

    Thanks everyone for your input. It does inspire me to start some beds. I'm worried about myself, I'll be all gung-ho on a project, but don't always follow through. However, the success I hear does make me reconsider!

    Mister_Gin since you've grown okra, is it too late to start some from seed? I just got some seeds from a friend yesterday and would like to plant them.

  • lazy_gardens
    14 years ago

    You can start okra now ... soak the seeds overnight and plant the ones that puffed up. Give the others another 24 hours to puff up. It cuts the sprouting time by a couple of weeks.

    Plant them 1/2 inch deep, about 18 inches apart, and after they get about a foot tall, mulch under them heavily to keep the spoil moist. They love poor dirt, lots of water and HEAT!

    they make a nice nurse plant for things that need afternoon shade - plant the okra on the west side of the the plants you want to shade.

    Here is a link that might be useful: Okra instructions

  • lazy_gardens
    14 years ago

    Here's my squash in the raised bed.

    http://www.flickr.com/photos/38617480@N07/sets/72157619569769890/

    It is made of an old waterbed frame. It's slowly composting itself, but it's been there for over 5 years and was free.

  • az-kikn
    14 years ago

    I have had a raised bed for years. I mixed the soil with compost, manure, mulch, and potting soil. I have raised all the vegetables you can think of. Summer and Winter. My bed is only 7 or 8 inches tall. I have a smaller area now but I still can feed 6 to 8 families. I add Manure each year. I also fertilize as needed naturally. (chicken manure tea, etc) Enjoy

  • az_pamperedchef
    14 years ago

    These responses are getting me very excited! I'm definitely thinking raised beds are for me. I have a spot on the east side of the house that I think would be perfect. Now I just need to get hubby on board! :-)

    Thanks everyone again for the pics and feedback. I so enjoy this forum.

    Lazy_gardens ~ I am soaking my okra seeds as I write, can't wait to get them in the ground.

  • lazy_gardens
    14 years ago

    chef ... okra prefers FULL sun. It's happiest with a southern or western exposure.

  • mister_gin
    Original Author
    14 years ago

    Here are some latest pictures of my raised beds. Raised bed #1 is the one I created after this post. The Tex ash tree nearby was much smaller then.

    I'm halfway to becoming a jungle.

    Garden Pics

  • az_pamperedchef
    14 years ago

    Mr. Gin-those pics look wonderful! I need to figure out how to post some pics of my garden. It doesn't look as good as yours, but I'll credit it to the fact that you have more years of experience.

    Lazy-I planted the okra seeds this evening on the west side of my house. I have to confess I am not a very good gardener in the respect that I don't amend my soil or baby the plants, so the okra should do just fine, right?

    I did mulch my cukes & squash with shredded newspaper. That's a good thing isn't it?

  • mister_gin
    Original Author
    14 years ago

    chef,

    Mulch is always a good thing. This is the first year I've been able to get enough leaves to cover both beds. I even had extra for the compost bin. My plants didn't look as good in previous years because of my erratic watering. The tops of the gardens would dry out way too fast without anything protecting it from our sun. I found this out the first few years of growing here. The beds in the picture get watered tomorrow. I'm holding myself to this once a week watering until we get really hot.

    I've yet to soak my okra seeds. I may have to try it next year.

  • lazy_gardens
    14 years ago

    I have to confess I am not a very good gardener in the respect that I don't amend my soil or baby the plants, so the okra should do just fine, right? It does just fine, as long as it gets plenty of water. I used a mattock to dig the holes in the caliche for my okra, and it was really happy. It was heavily mulched afterwards with about 6 inches of shredded palo verde branches (we killed a tree).

    I did mulch my cukes & squash with shredded newspaper. That's a good thing isn't it? Yes, it holds water and keeps the fruit cleaner and the ground cooler.

    http://www.flickr.com/photos/38617480@N07/3614605313/in/set-72157619569769890/ is my squash bed last year, also heavily mulched with shredded trees in and around the bed.

    Here is a link that might be useful: Neglected Okra :)

  • az_pamperedchef
    14 years ago

    Thanks Lazy! I can tell how neglected that okra is, sure is suffering.

  • mangledmind
    13 years ago

    {{gwi:411712}}

    {{gwi:411716}}

    {{gwi:411719}}

    {{gwi:411722}}

    {{gwi:411725}}

    {{gwi:404260}}

    {{gwi:411728}}

  • az_pamperedchef
    13 years ago

    Those beds look nice MM! You have them all over the place also. I like that idea. Thanks for sharing.

  • MaryMcP Zone 8b - Phx AZ
    13 years ago

    Nice beds!!!! Serious bed envy here. But I am challenged by putting together all that wood, not a carpenter by any means, so I found another solution for a quick and easy bed. Straw wattles. Here's my 'keyhole' garden. I found the wattles at a place on Union Hills near the freeway....if anyone is interested, I'll find the info and let you know.

    Before:

    {{gwi:411729}}

  • MaryMcP Zone 8b - Phx AZ
    13 years ago

    In process:

    {{gwi:409199}}

    Done: Not the best picture but it was late in the day by the time I finished, so it's a bit shaded. This was several weeks ago (6 or 8 maybe) and some veggies have begun to grow in....tomatoes mostly. I'll plant some flowers and garlic to cover the ugliness of the wattle itself so that in a year or two they will be camoflaged.

    {{gwi:411730}}

  • MaryMcP Zone 8b - Phx AZ
    13 years ago

    Addendum: These wattles are 12" in diameter. You can also buy them 18", or stack them if you need a deeper bed.

  • wabikeguy
    13 years ago

    Those straw wattles look great. Please...either post the name of the place or send me the info in an email.

    Thanks.........Dave

  • mangledmind
    13 years ago

    marymcp,

    That is an AWESOME layout. I was looking for those "wattles", but couldn't figure out the name of them. I wanted some for our property up north, to cut down on the snow melt erosion.

    And what a neat idea to use them as a raised bed garden container.

    I'm with wabikeguy (Dave), can you provide the contact info for the shop you purchased them from?

    Thanks,
    MM

  • mangledmind
    13 years ago

    az_pamperedchef,

    We have an odd shaped lot (partial pie shape), so "conventional" layouts based on square lots was not an option. So we did some research and tried to layout the beds with a 3' spacing in-between for walkways. We have more beds in front and a few more in the works now. It's a lot of work for sure. But the veggies are doing GREAT.

    Check out this link, it's what we are sorta basing our front yard on:

    Here is a link that might be useful: Raised Garden Beds - Plans and Layouts

  • MaryMcP Zone 8b - Phx AZ
    13 years ago

    Sorry, can't find the name of the place we went...it'll come to me at some point. In the meantime, I found this throug a Google search:

    Arizona Bag Company
    2530 West Buckeye Road
    Phoenix, AZ 85009

    approximately ½ mile west of I-17,
    on the northwest corner of
    25th Avenue and Buckeye Road.

    Open Monday through Friday.

    Will Call: 7:00am through 4:15pm.
    (phones open until 4:30pm)

    HTH.

  • rtl850nomore
    13 years ago

    Hey Mary you bought them at Border Construction Specialties 22425 N. 19th Ave.

  • MaryMcP Zone 8b - Phx AZ
    13 years ago

    Yeah! That's it! I think you told me about them to begin with. Thanks rtl....

  • jiml85254
    13 years ago

    Brand new to gardening and happened to find this great forum. We just built our first raised bed - a 4x8 that's 20 inches tall, and similar to the original posters, we placed the raised bed on the NE portion of the back yard - covering an existing rock area. We used composite decking from Home Depot and it turned out very nice. Now comes the fun task of filling it up as we hope to be ready for planting vegetables by August/September. Any suggestions on what type of mixture we should utilize to fill the garden? I guess what I'm asking is - if you had 20" of space to fill, what soil mixture would you go with?

    Thanks in advance...

  • desertaddie
    13 years ago

    After reading mail from May and June I admit I had a totally different idea about raised beds especially because of my iffy lower back. So, not giving up on the original plan of 24 inch high beds, is there a reasonable means to reduce the heat and evaporation by the correct choice of building materials?

  • mangledmind
    13 years ago

    jiml85254 - we use Kellog brand "Amend" and Potting Soil Mix along with a few other brands all mixed. Available from your local garden center, Lowe's, Home Depot etc...

    desertaddie - we lined our beds with landscape fabric. Used wood 2x12's.

  • strich
    13 years ago

    I use Kellog too. Trying a 50/50 mix of compost and top soil this year. I've built a bed from composite material for the shallow rooted veg and a deeper bed, (for potatoes this year) from block. Anyone else use blocks for beds. Interested to see how well they work.

    Here is a link that might be useful: Low Cost Raised Bed

  • regehr
    13 years ago

    My raised bed garden is about 13 feet square and surrounded by stacked bricks... can not remember the name now but they have plastic tabs in the back holding them together with a 14x10 inch cap. They work great and I can walk on them when I am working. I live in Chandler and have never had a problem with the heat but I keep the garden pretty wet.

    the price of brick is higher on the front end but they will last forever and look very nice.

    I took about 10 inches of dirt out from the bottom and put in all new soil. It was a long time ago but I know it was a lot. I add steer manure every year but need to add another 5 bags of soil, do not know where it is going.

    Every time I turn the garden over with the shovel the level gets back up near the top of the bricks. The soil is amazing... if I step in where I have worked my foot sinks about 6 inches.

  • luvkuku
    13 years ago

    I am using a old leaky stock tank about 2 feet high and 8 feet across. I had to put a row of posts across the middle so I could fill up one side at a time with bags of soil, my own compost, and potting soil. It is full now and I want to pull out the posts next for more planting space. I am using it because the ground squirrels cant climb the sides and destroy everything. I live in a remote desert/mountain area outside Buckeye on 20 acres with very few flat places, mostly rock. Nothing to do with gardening here is easy but oh so worth it when it works. I am at work now but will post pix when I can.