Raised Bed Gardening for Veggies and Herbs

I'm new to the forum and new to Raised Bed Gardening. We are in Zone 5b (MI) and have severly clay and sandy soil around our home. Thus, I'm interested in building a modest sized raised bed (4x8') to grow basic veggies (tomatoes etc) and herbs, adding some annuals/perennials for aesthetics. Can anyone provide insight into the benefits of building/using a raised bed vs just a 'regular' garden?

Mullet
I've been gardening in raised beds for 20+ years. Where I live there's no such thing as soil. It's all sand. My beds are either 4'x8' or 4'x16'. I've always used 2x6's of pressure treated lumber from Lowes or Home Depot. Three 8 foot long 2x6's gives you exactly the size bed you are looking for.
Obvious advantages, you can create whatever planting soil you want and keep it contained within the bed, while preventing grass and weeds from invading. And there's really not a whole lot of effort to just get it started. Just turn over the ground where you want to place your 'bed frame' & remove any grass or weeds that are growing in it. Add soil amendments as often as you like--create your own compost as it becomes available. I add more compost every year. Over time the soil in the bed really becomes an ideal growing medium. And the nutrients in the soil don't leach out very quickly. Start simple and let the bed mature over time.
My 2x6's are probably 10 years old now, so clearly they don't need to be replaced very often.

Raised beds are also very easy to cover with crop cover to keep things warm or mesh to keep insects off the crops.

Our soil is quite good and I still have used raised beds for years. Mostly what I do is like blmlb. Mine are made by 2x8's and I used countersunk lag screws on the ends and on center braces on my long ones. Mine are 18"x32 ft., 18"x40ft., 6x8, 4x8, and 2x8 and I am going to add one 4x4. I put in a cement sidewalk on one side and in the isles I laid down a weed barrier and the cheap indoor/outdoor green carpet on top of that. I grow mostly tomato and pepper plants and I mulch wherever I can. I use SRM red mulch and it is easy to attach to the top of the beds by nailing 1 1/2" long strips of thin lumber. I have almost no weeds in my garden. I also attach my home made tomato cages to the top of the beds. I did not think I would ever buy one of those high priced Mantis tillers however I had some small areas I wanted to till one at a time and did not want to rent and haul a rented rototiller several times. I could not believe what a good job it does and this year I will use it to till in my compost (which I buy) in all of my raised beds. It is easy to build a watering system on riased beds and to harvest and control the plants. The treated boards will last almost forever as mine are 20 years old now and look like they will last another 20 years. The statements by blmlb and Patbarr are right on. Once you used a raised bed, I doubt if you would go back to growing any other way. Best to you. Dale

Ditto on all of the above. I used railroad ties for my first one - cost a small fortune to build but will probably outlive me. This year I want to try the Cubed Foot/Square Foot pinciple to I am adding 7-8 4'x4' beds. I will use pressure treated 2"x10"s, and lath for the cross bars.

I MAJOR warning - do NOT skimp by bringing in a load of "really good" topsoil. Mine had so many doggone weeds in it last year I could just scream. Will NEVER do that again. I have the entire raised bed (8' x 21') covered with cardboard right now in the hopes of suffocating those l#$@&%$. Come Spring I will till the remains in with handy dandy Mantis. Yepper - I love that thing, too!

Apparently you two don't mind not having lots of earthworms in your raised beds. I won't allow a tiller of any kind on my garden properties. A tiller would chew up my earthworms, and they're my natural fertilizers and soil cultivators. I use a spading fork to gently turn over or stir my raised beds before planting in the Spring. My worm herds are a little disgruntled about being temporarily disturbed, but they remain alive and well!

Lettuceman,
I agree with you 100%. 10+ years ago after I had established a handful of raised beds, I found that there were very few resident earthworms in my beds. I quickly remedied that problem. I went to a grubby, smelly little bait and tackle shop and bought a pint container of fishing worms. The guy told me they were "Georgia Wigglers" and would be all i needed to catch bluegill. Didn't tell him what I wanted them for.
I put a half dozen of them in each bed and within a couple of years they had multiplied 3 or 4 times. Now, 10 years later I'm finding them in all parts of my yard, 100 yards from where I first planted them. Best investment I ever made. Don't think it would help me sell the house if I ever put it up for sale. ;-)

I have oodles of earthworms. I've even gotten to here I can move them from place to place. (Took a long time for me to get beyond the "eeeeeew" stage!)

Sequee,
May sound stupid, but whenever I find one on the pavement around my house, nearly dried out, it if still has a bit of life in it, I take the time to put it under a bit of soil. I have no idea how many I have saved. They don't talk, or, if they do, they don't speak loud enough for me to hear them. (Not that I have spent much time listening ;-)

I've found these corners to be an easy way to set up a raised bed:

http://www.improvementscatalog.com/product.asp?product=142380zz&dept%5Fid=12100&subdept%5Fid=12120

Since I stack them to have a 12" high bed, I also purchase 4 concrete stakes, as the plastic stakes that come with them are not long enough. All you have to do is slide your lumber into the slots.

The downside is that come in a 6-pack instead of an 8-pack; but two 6-packs are enough for one 12" bed and one 6" bed.

The corners are hinged so you're not limited to a square or rectangular bed, either.

Hey, Sequee, won't tilling bring new weed seeds to the surface? I've got a similar problem and I think I'm just going to cut holes in the newspaper layers to plant (where possible). Maybe this won't work so well...

Any time the soil is disturbed (by whatever method is used), weed seeds are brought to the surface. I've learned to tolerate them to a certain extent. I'm also reminded what an old-timer gardener friend once told me: "If the weeds don't grow in your beds, nothing else will either!"

I have a really big, mostly unused back yard w/hibiscus along one long side. Also, I have a sprinkler system there.
Do you think it would be feasible to have a raised bed where there are sprinklers as long as we replaced the present nozzles w/longer ones? The raised beds would be so much easier for us old folks to work in.

Ann

There are actually adaptors available to convert your sprinklers to drip irrigation. I think I saw them at Home Depot last year...

Thanks for the info on the adapters to make drip irrigation. I'll check HD.

Ann

We are hoping to kill off alot of them through suffocation, then we will re-till and pull out any obvious chunks. I'm hoping to till in "stuff", then I will place newspapers and add the new soil mix on top. Hopefully this will at least give me a fighting chance!

Re: earthworms...the first couple of times I "moved" them, they'd squiggle and wiggle and squirm like trying to break through from the clump of earth I was carrying. And I'd, be - look dammmmit, I'm Trying to be nice! Like they could understand what I was saying any better than they could understand what I was doing...OY!

Lettuceman: I appreciate your comments however tilling probably does not reduce the population of my earthworms a significant amount if any. I raised worms as a hobby until I took a job that required a lot of my time. I read everything I could get my hands on about worms and I am sure I still have many of the books and at least one CD on the critters. I learned about the regeneration of earthworms and discovered when I cut one in half with my shovel, I usually did not get two worms however as the vital organs in the worm are in the front segments, I would still have one. According to the scientist we taxpayers support, this is not 100 percent but close to it. I always add a generouse amount of high quality compost and as this is the worm's favorite food, I am probably increasing my worm population. Feed them and they will come. Dale

I had forgotten about my worm's capacity to regenerate. However, I'll stick with my spading fork because as I mentioned earlier, they get upset about being disturbed as it is. Don't want to make em mad at me enough to leave! Yes, the main reason I have lots of worms is because of the copious amounts of home-made compost that go into all of my beds. I really spoil my worm herds, and feed them all the coffee grounds I can get too!

Sequee: I hate to rain on your parade but I doubt if you can murder a weed seed by suffocation. If you can get the temperature up to 150 degrees, that would kill most of them. You might be able to do this with black plastic. I experimented with heating the soil in my beds last year. I used black plastic, red plastic, clear plastic and heat cables. I did a combination of them plus one with nothing but soil. This was early spring while still cool and the one with black plastic hit almost 90 degrees. A person might make high mounds and cover them with black plastic, or truck wash places use 55 gal. plastic drums, (some black), which when empty they give away or sell cheap and then cut the tops out, fill with soil and cover with a black trash bag. If the temp would reach 150 degrees by covering your bed with black plastic, it may not be 150 degrees very deep. It is important to make sure the temp does not go over 150 degrees. I am not into chemicals however there are some preemergent herbicides that do selective killing of weed seeds when they germinate and are approved for vegetable gardens. Scthoxydim, DCPA and Tripluraline for exampble. Roundup of course will kill emerged growing weeds and when I use it near my garden, I cover my plants with plastic bags. I had a ground cover growing among my flowers and I used a small paint brush dipped in Roundup and that worked. The bad news is that some weed seeds will be dormant for 20 years and then decide to germinate. You may want to post a sign, "Sequee's Backacher."

PlantLady,
Your earlier comment about being able to work in raised beds being a bit easier on the knees and bending is another VERY important consideration. When I first put my raised beds in I had several of them, 3 and a half feet wide (much easier to reach to the middle of the bed) and 8 feet long. Once in place, I then used my shovel to skim off the grass/weeds in the walk areas between the beds. Then I dug out the dirt between the beds maybe two inches deep and tossed it into my raised beds. I sprinkled my 'new' walkways with a bit of cedar mulch so i wouldn't be tracking mud into the house.
Primary reason I did that was so that my raised beds would have a little extra "starting dirt", so to speak, but more importantly, I was closer to the bed itself because I was standing a little lower below the level of the beds. It makes a difference.
As for weed seeds, that will be a problem no matter where you garden. Ain't no easy solution. With a new bed I would just check it every day or two and be prepared to pinch out any emerging plantlife that you know you don't want in the beds. After 2-3 weeks of diligent pinching the beds will be clean and clear. Periodically, of course you'll have to pinch out any new unwelcome weeds. It won't be a big hassle to stay on top of because your little raised bed is essentially an isolated garden.
As for the sprinkler system, I'm not sure you'd even want to mess with it. If the grass likes it, chances are the veggies will like it just as much. If I had a sprinkler system already in place, I'd do my best to work around it to maximize the benefit it would offer to my raised beds.

Actually, it works quite well. We did this on an 8' x 18' patch in my yard last year and in 2 4'x6' patches in my neighbor's yard, and it killed off a good 80% of the growth. I subsequently covered my area with black plastic to create a container garden and Paul covered his with bark, and we both had very little weed regrowth in those area. (That's why they tell you to cover the earth between rows with cardboard or newspaper. It not only helps with weed regrowth, but it's organic so you can just dig it back in instead of having to pull it up like you have to do with plastic.) I realize it will be tougher in the raised bed because the dense weeds were so out-of-hand. It will be fun to "play" with, though, and I promise to keep you posted with a "yeah" or "neah". in fact, if it doesn't work as well as it did in the "south forty", you'll probably hearing me grumbling all the way in CO!!!

I use a soaker hose in my beds and it certainly makes life alot easier. I just turn them on before I go to bed and turn them off when I leave for work. No muss - no fuss!!!

It ain't no raised bed type thing, but I placed large cut cardboard boxes and placed them around my new 3' blueberry trees last Sept. Then I added 20 layers of news papers on top of that. I had to wet the boxes, lay paper, wet the paper and wet again. I continued to keep the paper wet to damp to avoid the wind from blowing all of it away. I also did the same thing to my 8' X 10' onion-garlic patch plus, I covered that with a heavy topping of leaves.
The area is about 8' X 32' (3 blueberry trees) and so far it is working very well. No signs of grass or weeds came up through the unusually warm weather we have had here in SE Michigan. I did have to cut the rest of the yard 3 different times since I put down the 'board and paper.
Next spring will give me a better view as to how well this works.
Later!

That basically what we did, only we put the papers on the bottom. We figured there'd be less of a chance for the wind to blow the c'board away, and it would be easy to pll up the cardboard and till in the mostly dissintigrated newspaper. The year before Paul bought a new frig in early winter and threw the box into a back area nea his composter. The area never did come back which is what gave us the original idea, then a little research confirmed that this was recommended by alot of old time gardeners.

Nothing to lose, I say!

Actually, I won't be planting just veggies in my "garden". I propose to kill out the grass by laying down many layers of

newspaper to cover the area avoiding the sprinklers, build up the border w/treated timbers (because we have termites here) and put a good mix of sterile soil, compost, sand - whatever - and plant away. My main concern was the sprinkler system which we cannot ignore or make go away. We have St.Augustine grass here.
Thanks for the input. I definitely think the job is doable and the raised bed will be an asset.

Ann

When I was living at a previous home with very limited space, I splurged and purchased one of these:

http://www.territorial-seed.com/stores/1/Raised_Bed_Container_Garden_P142310C310.cfm

The planting bed is 2' X 5', and 8" deep. The bottom is a porous fabric (with support) so root rot is not a problem. It only takes a screwdriver to put it together (but I recommend a drill with screwdriver tips!). I also embedded a heating cable so I can use almost year-round in my climate.

We use these at the Adult Day Care Center. I do a Horticulture Therapy Group, May-October, and the tables work wonderfully. We have 3 of them, one's dedicated to Wild Flowers, one's for herbs, and they other has done everything from strawberries and melons to peppers and eggplant.

No squash?

Given the 8" depth, I use mine primarily for lettuce and salad greens.

Newspapers and or cardboard mulch really pay off in raised beds and other gardens. Common weed seeds are suppressed as they need light to germinate and a few may rot especially if the soil is moist. Most will stay dormant and this is called secondary dormancy if they lack oxygen. I used to use newspapers and I always put grass clippings on top of the newspapers as we have very strong winds here. Earthworms really thrive on newspapers and like cardboard even more so this is an added benefit. I always make sure my mulch is removed by early spring so the weeds will grow and then I spray them with a weed killer. Then I till the soil which will bring addtional weed seeds up to or near the top and when they start to grow, I do my final spraying. Then mulch and plant.

plantladyhou, I'm sure you may know, but for anyone else, if you can't get around using your installed sprinkler system, it is very important to water in the morning or you will be inviting all sorts of fungus and bugs, especially with you 100% humidity year 'round. Also, to try and prevent the st augustine from growing up through your raised bed, put at least a 12"(2' would be better!) barrier around your bed, using the paper, cardboard, weedfabric, etc covered with wood chips or something to make it look attractive. Even better(if not to much work) is to dig down about 6-8" where your bed perimiter is and install fabric, treated lumber, or some kind of barrier to keep things (St A roots!) from growing under into the bed. My grandad grew a lot of roses in raised beds in the Memorial area back in the 60's and 70's, and even at 6-7 yrs old, I can still remember how beautiful they were.

PlantLady,
Here in N. Fla we have 2 dominate grasses -- St. Augustine and Bermuda. With a raised bed, I've never had any problem with the St. Augustine grass. It tends to grow up to, and over the top of the raised beds. It has always been a simple problem of just ripping out the runners, or using a weed-eater to keep it at bay. Bermuda grass, however, has been a much greater problem. Even with the raised bed borders 'planted' an inch or more deeper than the surrounding soil, Bermuda grass likes to put out runners well below soil level.
Typically, every spring/summer I find myself having to deal with Bermuda runners that have burrowed under the planting bed border and popping up in the bed itself. I then find that I have to dig down into the inside AND the outside of the bed border just to keep the Bermuda from invading.
Bermuda grass is a mighty fine grass for any lawn, but it can be a real pain in the keister to keep it out of a raised planting bed.
I mentioned earlier that an adjacent sprinkler system should not be a very big problem. The beds will need just as much water as the rest of the yard your sprinkler system is servicing. As Vadap has indicated, it is always best to use your sprinkler system early in the day.

A question: Many of y'all have mentioned using treated lumber to build your beds. Doesn't whatever the lumber is treated with leach into the soil and maybe get into the plants (and thus, into you)?

I use untreated green cedar 2x6's and don't problems, but I don't have some of the issues that some of the southern gardeners have...

PatriciaS,
I've used pressure treated lumber (pine) mostly from home depot for 25 years. During that time I have never read anything negative about treated lumber, except to avoid railroad ties treated with creosote.
Here is a quote from a very informative website:

Pre-Treated Lumber for Grow-Boxes
Author: Jim Kennard


Q. Is it ok to use pre-treated wood to make my grow-boxes?

A. Fresh creosote is not good to use, but if it's aged, like that in old railroad ties, it's alright. Also, the treated lumber from stores in the USA have historically had some arsenic in them, but I have been told they must be arsenic-free, starting in 2005. I would advise anyone using treated lumber to ask the store personnel where it is purchased, before using it.

That info comes from http://foodforeveryone.org/index.php. Click on their faq's, there is a huge amount of good info there.

Well, this was often a heated debate amongst many. "Treated" lumber was for years treated with chromated copper arsenate, "arsenic". And research in some areas showed that the arsenic actually did leach into the soil and was taken up by food crops. Some research showed that the arsenic was most prevalent with a foot or so of the lumber, other research showed it to be farther away, and much of the research pointed out that the distance was due to the type of soil structure, heat, and/or rainfall. (For active compost bins it is still recommended to not use CCA treated lumber due to the compost heating up and pulling the arsenic from the lumber.) Also, there was evidence of the CCA being absorbed into the skin by children (wooden playsets/playgrounds) and even by children playing in the soil under treated-wood decks.

Blmlb, the reason the EPA banned CCA treated lumber in 2003 (actually there was a two year waiting period before the ban went into effect) was because of many of those experiments/research. Nowadays,CCA treated lumber is still available for certain commercial uses but is not available for residential use (supposedly).

As an aside, of course we know that arsenic can kill in certain doses, but it is also readily available in our natural soils in minute amounts. In small amounts we're safe (as with many other things).

Personally, I have not used CCA treated lumber around food crops and am still hesitant to do so. Also, many years ago I acquired some railroad crossties and used them to border a flower bed and our driveway. The premise at that time (even with Rodale Institute) was that the crossties, being most likely very old, had already leached out their creosote/arsenic over the years of their use and were safe. Unfortunately, five years later it was determined they hadn't had the time to fully leach out their "poisons". Go figger, eh?

And so, I know many people who are not the least bit concerned about using CCA treated wood for their raised vegetable beds, I know others who would never use it, and other who wish they never had.

I guess it's another one of those personal choices we make, eh?

Shoe.

PS, the "new" treated lumber is said to be safe for human contact, decks, playgrounds etc. If anyone knows of any research about its leaching compounds having an adverse affect (or not) on the soil, organisms, and humans I'd like to be alerted so I can read up on it some more.

I would like that alert also.

Shoe raises a very good question about CCA treated wood. A 2x6 12 ft. long contains enough arsenic to kill about 250 people and it is against the law to burn in all 50 states. Incineration does not get rid of inorganic arsenic and the ashes from CCA wood are extremely toxic. (So when we are done with CCA wood, what do we do with it?) Shoe's statements about children should be taken very seriously by all concerned. I would be suspicious of studies done by the lumber industry or pro environments groups as they would probably dertermined the outcome and then do the study. There has been a recent study by an independent group that does not have a dog in the fight. People are said to be able to tolerate 40 ppm. There study of 3 yr. old raised CCA beds showed 20 ppm from 0 to 2 in. 4.8 ppm from 6" and 4.2 ppm from 2 ft. all from the edge of CCA wood. Outside of the bed, the reading was 4.2 ppm. They tested various crops and tomatoes tested at 0.14 ppm (About everything we eat or drink has some arsenic in it.) Root crops tested a little higher. Overall crops do not take up much arsenic. They stated the plants would die before they would be harmful to humans. They also stated the E.coli 0157.H7 was more of a danger then arsenic. If you have CCA raised beds and still are worried about them, you can replace your soil, seal the wood with a good paint or water proof sealant that does not contain acid. You also could have a soil test taken. (Or give them to your neighbor) A very good respirator should be worn when sawing or shaping the wood, do not use galvanized nails, and wear gloves while handling it. My beds are made of CCA wood and I did replace the soil several years ago. I may add some new beds and if I do, I will use treated lumber without arsenic in it.

thanks bluejack...

Those figures are right in line with other research. Much obliged! (I wasn't aware of the galvanized nails and their role though; do they add even more toxins we should be aware of?)

And yes, sealing the CCA treated wood with paint or sealant is a great recommendation. I should do that with our deck but at this point am exercising extreme laziness. (Besides, I seldom get time to enjoy that deck anyway! No fair!)

Shoe