1
point
How do I construct a raised bed for growing vegetables? What are the best materials to use?

General    United Kingdom

The soil in my garden just isn’t up to task so I have been reading about how you can build a raised bed and I think that this is the solution. I have some pine wood in the garage, can I use that to build it? What is the best soil to fill it with?



Posted by: Greg Coyle (3 points) Greg Coyle
Posted: February 23, 2013


Charlie B. commented,
I would like to piggyback onto this question, asking for experience with cost/benefits of different types of wood borders. Is the non-arsenic treated lumber safe to use?
over 6 years ago.

Lindsay McMenemy commented,
Hi Charlie, you probably want to post this as an new question to make sure as many users as possible see it and can answer. Thank you!
over 6 years ago.



Answers

3
points
There are major advantages to using raised beds to grow vegetables if the soil in your garden is poor. Obviously, you get to fill the bed with soil that is suitable for vegetable growing, but also soil drainage is improved and the soil warms up faster in Spring, giving you a head start on the growing season. In addition, a well designed planting plan can increase your productivity and you can enjoy better harvests.

One of the most common raised bed designs is an edged raised bed, produced by constructing a frame from materials such as timber, plastic or brick (see Figure 1). When planning, you should give consideration to how you will access the centre of the bed. If you make the bed too wide, you may be unable to reach plants in the centre. A sturdy construction may allow you to place planks of wood as walkways, but it is easiest to simply reduce the width of your construct so that you can reach the plants from the side. The bed can be as little as 4 ft × 4ft and should raise the soil between 6 and 12 inches. The material you use depends to some extent on your budget. Pine lumber if fine but is less durable and will need replacing quicker than a more expensive timber, like cedar. Be careful that any timber you use has not been treated with any toxic chemicals like creosote as they may leach into your plants. If you are unsure about the history of the material then you should line the inside of the bed with a sheet of polyethylene to be on the safe side.

To construct a wooden frame, simply cut the wood to the desired size and secure the corners with screws, corner brackets or by nailing in wooden support posts (see Figure 2). To reduce weeds in your raised bed, you may wish to lay a piece of weed mat, pieces of cardboard or a thick layer of newspaper in the footprint of the bed and then position the frame over the top.

One of our users, David Goodman, recommends placing large chunks of wood at the bottom of your bed which will store water as they decompose. He has a great gardening blog and there is some excellent information and images that describe how to fill your raised bed (http://www.floridasurvivalgardening.c...). I have tried to summarize in Figure 3.

After all of this, you are finally ready to plant! A good planting plan is key to maximizing the productivity of your bed. Planting in a raised bed is different from elsewhere in the garden as you should aim to concentrate on planting in blocks, rather than row and also practice succession planting (see https://www.plantvillage.com/posts/251) to reuse space when it becomes available. Be aware of how much space specific plants need. You can use square foot gardening technique - divide your bed into square foot sections. You can make planting easier by marking out the sections with string. There are many plans you can follow for planting, an example is provided in Figure 4. This plan represents how many of each plant type can be planted per square foot of bed (i.e. 1 squash plant requires 2 square feet).

Finally, always remember you can use vertical space too by positioning trellises for squash or cucumber to vine around.



Posted by: Lindsay McMenemy (2 points) Lindsay McMenemy
Posted: April 10, 2013




2
points
Mel Bartholomew, author of "Square Foot Gardening," recommends a 3-part mix of peat moss, vermiculite and compost. That works quite well, as does pure compost.

I've used a variety of things: old manure, homemade compost, sifted dirt from my chicken run, bits of charcoal (not briquettes), sawdust, rotten leaves, bark chips, etc. A broad mix is better than any one thing alone - for instance, if I used just sawdust I'd have serious nitrogen deficiencies to overcome. But mixed with manure and chicken run dirt, it behaves just fine.

My favorite edging for my beds is the lowly cinderblock. With a little work, they can look good - and they never need replacing.

Check out what my wife and I did here:

http://www.floridasurvivalgardening.c...

Pine will work but you will need to replace it regularly - it doesn't last very long when exposed to the elements.



Posted by: David Goodman (67 points) David Goodman
Posted: February 26, 2013


Lindsay McMenemy commented,
David, that mosaic decorated raised bed is fabulous!!! Any chance you could upload a couple of pics to your post?
over 6 years ago.

Tanya in the Garden commented,
I love the hugulkultur pit! And the mosaics are wonderful!

At community garden plots, I've used recycled wood for the edges of my plots. It does tend to degrade over the years, but it holds together surprisingly well. I've learned that if the wood is starting to decay, it's time to change the configuration of the beds anyway.

I have some edged beds and some mounded edges. It is easier to maintain the edged sides, but that's also where the snails and slugs hang out during the day.

over 6 years ago.



1
point
I came across a really nice extension document from Alabama U. The link is here and I place some of the key text below since the document covers lots of things besides the material. http://www.aces.edu/pubs/docs/A/ANR-1...

"Raised beds can be made just by mounding the soil, but these beds require a lot of maintenance. Most
gardeners prefer to use framing materials to contain the new soil. Old railroad ties, landscape timbers,
wood planks, rock, concrete blocks, or decorative bricks are commonly used to hold and raise the soil"

Note that some advice about railroad sleepers says they are not good unless well weathered. http://www.extension.umn.edu/distribu...


good luck



Posted by: David Hughes (43 points) David Hughes
Posted: April 9, 2013




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