Organic Gardening Techniques (Companion House Books, 2018) by Nick Hamilton, offers gardeners insight for planting and growing various fruits, vegetable and herbs. Find your gardening niche with help from Hamilton and see how your gardens can blossom. This excerpt can be located in Chapter 3, “Organic Growing Methods.”
There are other materials besides wood that can also be used very effectively as edging for raised beds. Everybody will have something that they prefer, but there are far too many to mention them all.
Railroad ties tend to be treated with either tar or creosote and cannot be bought for use in the garden. It is possible to buy new landscape timbers, which are made to the same dimensions from new wood, having never seen a railroad line! These new timbers are very often treated wood; however, inquire before purchasing. They make excellent raised beds, usually having dimensions of 9 inches (23 cm) x 6 inches (15 cm), and can stand directly on the soil surface or at a higher level by stacking one on top of the other. If stacking timbers, you will need to attach wood between them to secure them. When using a very deep bed, it is always worth ensuring there is somewhere for the excess water to pass out of the bed. Do this either by cultivating the soil at the original ground level, so that excess water can filter away in this direction, or by making sure that the bed’s edging is not too tightly sealed, allowing excess water to pass out gradually through the joints in the timbers. You can also create a raised bed with no edging at all, using careful soil placement and string lines to keep it symmetrical. The soil will be naturally raised by the addition of organic matter, with the soil between the beds, used as paths, sinking slightly as it becomes compacted.
Raised Beds without Edging
You can also create a raised bed with no edging at all, using careful soil placement and string lines to keep it symmetrical. The soil will be naturally raised by the addition of organic matter, with the soil between the beds, used as paths, sinking slightly as it becomes compacted.
Round Fence Posts
Round fence posts, with a minimum 2- to 3-inch (5- to 8-cm) diameter, can be cut up into the lengths required. Allow about 18 inches (45 cm) can be buried in the ground to ensure the bed’s edging is secure and does not move under the weight of soil. This depth is adequate for beds up to 24 inches (60 cm) high, but taller beds will need to have the posts buried deeper into the ground. Buy the posts from a lumberyard because that is where you are most likely to find untreated posts.
Synthetic wood is becoming more and more available. It is made from recycled plastic and looks very effective. It can be nailed, cut, and even planed like real wood but obviously lasts much longer. Beds are constructed in the same way as for sawn lumber. Bricks
Bricks can be used in several ways, although their use tends to mean permanent beds rather than ones that can easily be chopped and changed at a later date. If the bricks are going to be laid flat and mortared into layers, the final height of bed is endless, as long as there has been a proper footing put in place. When constructing our asparagus raised beds, we also wanted to make an ornamental feature of them, so we made them 36 inches (90 cm) tall. I also find bricks laid at a 45-degree angle very effective, and these can be held in place just with the soil, although they will move fractionally over time. To keep them totally in place, they would need to be set in mortar. A variation on this theme is to lay the brick vertically, which gives a slightly higher bed than if set at an angle. Placing bricks horizontally in rows is just one way to use bricks for a raised bed.
Soil in Raised Beds
Once you’ve constructed the beds, you need to turn your attention to the soil. Lower raised beds can have the soil improved as previously mentioned, with the deeper beds having to be filled with a growing medium. Because we garden in a heavy clay soil, I like to use equal parts soil, compost, and gravel (coarse grit) as the deep-bed growing medium. The soil gives the mix body, while the garden compost or well-rotted farmyard manure helps to retain moisture and also adds some nutrients; the gravel keeps the mix fairly open so that excess water can easily drain away. I have found that a pea-sized gravel does the job adequately. Remember when filling these deeper beds that the soil will sink slightly, so have some mix ready to top up with. As mentioned right at the start, raised beds, by the sheer nature of raising the soil, will have a much better drainage than the surface soil. It is also easier to manipulate the soil in order to obtain the right soil for the crops being grown. Another advantage is that the layout of these beds and the minimal use of pathways mean there will be more yield for the area used than there would be if growing in the traditional row system. Finally, for gardeners such as us who have a heavy clay soil in which to grow all of our produce, raising the height of the soil and improving drainage give us a much earlier crop than growing in wet and cold surface soil, as the drier soil warms up more quickly.
Tiles that are specially made for the purpose tend to be either Victorian in style or very modern. As with bricks, they can be set in the soil or in mortar, and also do not give a great depth of soil above the original soil surface. This style should be seen primarily as a decorative feature because to obtain a decent depth of soil above the original level the tiles would really need to be three times the size.
In the right situation, bamboo roll or larger bamboo poles cut into lengths can be used and set in the ground using the same principles as for fence posts. It would probably give somewhat of a Japanese feel to the area, so would be limited in its use. Woven Willow or Hazel Woven willow or hazel gives a lovely old-fashioned look to beds but does not last very long—maybe only two or three seasons—when used to contain soil. It would be far better, if you want to achieve this look, to make the beds out of a longer-lasting material and surround it with the willow or hazel.
I would not use concrete blocks, slabs, or paving stones in our raised beds at Barnsdale, as they do not fit into the look of our productive gardens; however, they do make excellent raised beds and will last a lifetime. They are all very heavy, and thus require setting into the soil or mortar in an adequate way so that there is no risk of them falling over and causing injury.
For anybody who is a wine aficionado, overturned wine bottles make a very decorative edging for raised beds. They are quite tough and will take knocks and bumps to a point, but, once broken, they are obviously very dangerous and would need to be replaced immediately.
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