emiwri
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Posts: 51
Joined: Wed Feb 14, 2007 6:42 pm
Location: Indiana

What is the best soil for a raised bed garden?

I'm getting ready for my 1st spring sowing in a new house and have decided to use raised beds and buy soil for them. I was all happy and ready to buy some topsoil and some peatmoss too when a gardening friend said to be careful where I buy soil! She began telling me about harmful nematodes that can be brought in with the soil, how they wreak havok on a garden and the only solution is to move. :shock:

So now I'm very worried about buying soil. Does anybody have tips for avoiding the purchase of soil contaminated with nematodes? I'm not sure I can go to Lowes and ask whoever is working the garden center where they get their soil without expecting a shrug and look of irritation. I went to a local nursery but their soil is priced so high, something like $60 for a cubic yard of dirt! Uhg.. will the budget prevent me from starting a garden this year? :cry:

Also, I still haven't decided what composition of gardening mix to use. I was thinking of top soil, peat moss, and compost but my compost is not likely to be ready in time and buying it is quite expensive... I'm curious what others have used and how it's worked out.

Thanks!

Newt
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Location: Maryland zone 7

Hi Emiwri,

Congratulations on your new home and welcome to The Helpful Gardener.

Since you mention your budget as a consideration for starting raised beds (as is the case for most of us), why not use the soil you already have and ammend that? Do you really need to have raised beds? Using your native soil means that you will need to add lots of organic matter, of which compost is great. With the money you save from not having to purchase topsoil and materials to build your raised beds, you could purchase compost until yours is ready. If you are going to do a large garden you could purchase compost in bulk and have it delivered as it's less expensive then a comparable amount of bagged compost.

When I start a new garden bed I like to add 4" of compost to the bed and turn it in.

I don't know when you started your compost, but if you turn it once a week and have your balance of greens, browns and moisture correct, it should be ready by spring.

I do not recommend the use of peat moss for several reasons. It is low in nutrients, once dry is difficult to rewet (ever notice that with houseplants?) and the depletion of the peat bogs is of some concern.

I'm not that knowledgable about harmful nematodes in purchased top soil, but I've been answering questions on boards for about 6 years now and I think it was mentioned by someone once. I have purchased bagged topsoil and never had a problem. Maybe someone else will come along with some ideas. It's my understanding that heat destroys most of the harmful nematodes in soil and the addition of organic material such as compost add micro-organisms that kill most harmful nematodes. You should find this interesting.
https://ipm.ncsu.edu/urban/cropsci/c06disea/nematode.html

If you do decide to build raised beds the best ratio I know of is 60% screened topsoil to 40% compost.

Newt

emiwri
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Posts: 51
Joined: Wed Feb 14, 2007 6:42 pm
Location: Indiana

I was leaning towards raised beds for the drainage. Midwest yards are often known for their lakes during the rainy seasons and I didn't want to take a chance. Plus, I've already built the frames for the beds. If sort of iffy about using the existing soil. I believe the previous owner was a customer of true green chem lawn and I'm concerned about gardening in leftover lawn chemicals. Also, I'm waiting 'til the snow melts to test it but the soil locally tends toward the acidic side of the pH scale which would be ideal for blueberries, but would need amendment like peat moss to make it more suitable for most veggies and tomatoes.

As far as compost goes, the local nursery sells aged compost in tracter scoops charging $95 a scoop!

As for my own compost, we have a foot and a half of snow over it. I know it's frozen at least a foot's depth and I am unable to amend it and turn it at this time. I believe I was unable to get it hot enough before winter temps came. However, the weather forecast is looking favorable so I may be able to try it again during the coming week, and I have a supply of leaves I can collect from. Unfortunately, the whole thing will be soaked thoroughly when the snow melts and it will probably take a fair amount of time for it to dry to simply moist.

I was planning on using peat moss because I have used it since I moved to the midwest to loosen up clay rocky soil (none of my carrots split in the ground!) as well as improve drainage. Since the raised beds should make drainage pretty good, peat moss may not be neccessary

I'm beginning to think that the nematode thing isn't all that common in purchased topsoil but I'm still paranoid all the same.

Thanks Newt. You are always so quick to reply! :)

Newt
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Joined: Wed May 26, 2004 2:44 am
Location: Maryland zone 7

Emiwri, you are very welcome! Well, since you've already built the frames you're halfway there. You might want to consider looking in the yellow pages for screened topsoil or do an internet search. Many places that sell mulch in bulk also sell screened topsoil.

Most veggies prefer a pH of neutral to slightly acid.

Peat moss is not alkaline, it has a low pH and is acid. You should find this helpful. There's even a comparison of peat to compost as you scroll down. Compost is excellent at helping to break up clay soil too. I do like it for covering the seeds of carrots though.


Newt

Durgan
Cool Member
Posts: 82
Joined: Fri Mar 02, 2007 3:50 pm
Location: Brantford, Ontario, Canada Zone 5

My hands on experience utilizing a raised bed.

Today 30 April 2006 Zone 5 I decided to enlarge my vegetable garden by 8 feet. It is 36 feet long. First I removed the sod with a kick sod cutter, then spaded about a foot deep, then rototilled the lumps, then raked the chunks that wouldn't crumble. Today's effort took me about 8 hours. It is a real good workout.

I broke the sod by hand and put it through a Yard Machine to shred the clumps and put it back onto the bed. This took about three hours. Not a bit of grass came up later in the season. The Yard Machine effectively killed the grass roots.

Adding compost to my new bed. I can only pick up about half a cubic yard per day from the city, so it will take me a few days to complete the bed. I worked it in well with the underlying soil using my new Honda mini-tiller. I will add about three cubic yards. I think the pictures depict the high quality of the compost. I can purchase this compost for $40.00 per yard, but I prefer the free compost and don't object to the labour. I pick up about half a yard per day. Two fourty five gallon garbage cans. I have a wooden box in the back of the van that takes exactly one-half yard.

7 May 2006. I decided to add some fiber to the new garden bed. The tree mulch was put through my yard machine to make smaller pieces then spread over the bed, and worked in with my new Honda mini rototiller. Now all I need is some rain and then I will plant my vegetables.


Apparently the effort was not in vain. All plants are growing extremely well.
Durgan.

emiwri
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Posts: 51
Joined: Wed Feb 14, 2007 6:42 pm
Location: Indiana

Thanks Durgan! I loved seeing all the pictures of your garden area as it progressed! It looked like a lot of work!

Where did you get the free compost from? I'd like to see if they have something like that around where I live.

We found a chipper/shredder machine on clearance so we bought it, I'm real excited about it because I can use it to shred up garden wastes to compost quicker. I hadn't thought of using it to "sift" the dirt clumps.

Durgan
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Posts: 82
Joined: Fri Mar 02, 2007 3:50 pm
Location: Brantford, Ontario, Canada Zone 5

emiwri wrote:Thanks Durgan! I loved seeing all the pictures of your garden area as it progressed! It looked like a lot of work!

Where did you get the free compost from? I'd like to see if they have something like that around where I live.

We found a chipper/shredder machine on clearance so we bought it, I'm real excited about it because I can use it to shred up garden wastes to compost quicker. I hadn't thought of using it to "sift" the dirt clumps.
The chipper shredder is a great addition. I break up sod using the machine. I tear it into about 9 inch chunks and throw it into the hopper. It works best if the clump is slightly damp. Too wet and it clogs the machine. Too dry and a lot of dust is created. Never has grass grown from the reduced pile since the roots are effectively destroyed.

The mini rototiller works best for destroying dirt chunks. The fast rotation simply claws away until reduced. A larger tiller simply kicks dirt chunks aside. I have both, but almost always use the little tiller now. The tiller will not break up sod sufficiently.

Our city allows two garbage cans full per day during the month of May. I go everyday with a box made to fit into the back of the van. I interpret two garbage cans as 45 gallon drums, so I get about half a yard per day. Over the last three years I got 45 yards. This is all vegetation compost and is excellent quality. If I had to buy it the cost from a greenhouse is about $40.00 per yard plus $35.00 delivery, so one pretty well has to buy a 9 yard truck load. This is about 72 wheelbarrels full. The measurement is about 7 or 8 wheelbarrows per cubic yard.

The wood chips are dumped in a local park for public use. I pick up some of these periodically and mix into the soil, also I use them for mulch. Thse chips are often partially composted and are mostly hardwood chips. I avoid evergreen as a general rule.

My compost area
Since composting is an integral part of gardening, my experiences are presented. I turned over the pile today, and will not disturb this until it is removed for putting on the garden beds, probably in the spring 2007.

All vegetable matter from the gardens is put through a yard machine to chop into small pieces. My neighbor adds grass cuttings from two large properties. I only get about three yards of compost from all this vegetation. It takes a great amount of garden waste to make any reasonable amount of compost.

24 July 2006
This ten horsepower machine is used to chop up all waste foliage. I make a pile of foliage, and when there is enough I wheel the machine out, and chop up the waste. It only takes a few minutes. I use to do this with a machete on a wooden block. It disposes of the branches and waste plants in a clean and quick manner.

Durgan.

Newt
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Joined: Wed May 26, 2004 2:44 am
Location: Maryland zone 7

Emiwri, many cities and towns have free compost programs. You can call your local landfill, city government or do a google search with:
town name + Indiana + free compost

Do keep in mind that you don't know what went in to making that compost. There could be grass clippings from grass that has been treated with synthetic chemicals, etc.

Newt

emiwri
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Posts: 51
Joined: Wed Feb 14, 2007 6:42 pm
Location: Indiana

Thanks. I gave the google a try but didn't come up with anything. Oh well, looks like I'm paying unless I can get my compost going. :P

Newt
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Posts: 1868
Joined: Wed May 26, 2004 2:44 am
Location: Maryland zone 7

Emiwri, try searching with your county name and see if that gets you anything. Did anyone mention to contact your local extension service? They might know. I'm too lazy to read all the posts again. :?

Newt

emiwri
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Posts: 51
Joined: Wed Feb 14, 2007 6:42 pm
Location: Indiana

Thanks again Newt! That should do it.

emiwri
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Posts: 51
Joined: Wed Feb 14, 2007 6:42 pm
Location: Indiana

So here's how it's going:

Yesterday I installed the 1st raised bed. The dirt under the grass is so dark and rich looking, we decided just to use our own dirt and pick up some compost somewhere to ammend it. Probably should still do a soil test? Aw, probably not neccessary if I add plenty of compost.

In the 4x4 plot of soil we found lots of small worms, only 3 cut worms, and a millipede. There are some counties within long driving distance that offers free compost but the cost of the trip may not be worth it. One nursery offers tractor scoops of aged compost for about $50-$60 and the other offers 40lbs. bags for 3.49 each.

I found out that my compost wasn't doing too badly as it was nice and soft under the frozen bits. So I moved it to the other bin adding leaves as I went and tossing in worms found while preparing the garden beds. I have lots of grass sod now since I'm pulling up 3 4x4 areas worth. Right now I'm tossing it in the now empty compost bin to hopefully dry out before adding to be composted. I read that failing to do so can cause the formation or smell of ammonia in your compost.

Is any body else getting ready for spring planting yet?

Newt
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Posts: 1868
Joined: Wed May 26, 2004 2:44 am
Location: Maryland zone 7

Wow! You are on a roll and a good one at that! :D :D
The dirt under the grass is so dark and rich looking, we decided just to use our own dirt and pick up some compost somewhere to ammend it. Probably should still do a soil test? Aw, probably not neccessary if I add plenty of compost.
How cool! 8) Unless you think there is a reason to do a soil test you probably don't need one. I know alot of folks will probably disagree with me.

Newt

emiwri
Full Member
Posts: 51
Joined: Wed Feb 14, 2007 6:42 pm
Location: Indiana

The bags of "compost" at the other nursery turned out to be cow manure. On a whim I bought a few bags (they were relatively inexpensive) of peat hummus from the other nursery. Then I found some organic fertilizer clearanced at walmart *sigh*.

I did a soil test because I happened to have an old soil test kit laying around and the results were not to great in the nutrient department, but it's hard to be sure because the test kit was really old and the capsules were beginning to dissolve.

Oh well, I went ahead and planted a few cool weather crops and covered with insulation blanket. We'll just have to wait and see if anything germinates.

Newt
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Posts: 1868
Joined: Wed May 26, 2004 2:44 am
Location: Maryland zone 7

The different types of peat
[url=https://www.ext.vt.edu/departments/envirohort/factsheets2/landsnurs/jan91pr5.html]Peat humus[/url] originates from hypnum moss, reed sedge peat, or woody peat. It is in such an advanced state of decomposition that the original plant remains cannot be identified. Peat humus is dark-brown to black with a low moisture-holding capacity. Unlike the other peats, it contains a small amount of nitrogen (2 to 3.5 percent). Peat humus, also known as black peat or Michigan peat, is quite heavy compared to the other peats. Its pH varies greatly (from 4 to 8 ), and it is characteristically sticky when wet.
I agree that an old test kit is probably useless. If you really want to know what condition your soil is in it would be best to contact you extension service and send samples to them.

Newt

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