Building a raised bed with sleepers is an excellent gardening project to use for a business card awakening project, because it looks like it needs a professional but actually doesn’t. If you are capable of using a drill, leveling a surface, and moving some heavy wood (with a helper, hopefully), you can construct a solid, attractive raised bed in a weekend, and can count on it to last for at least 15 years.
The benefits of a raised bed extend beyond aesthetics. Raised beds have soil that is heated earlier in the spring, have improved drainage, and allow you to have full control over the soil. For anyone struggling with clay and waterlogged soil beds for a while, the last point in particular is a sufficient benfit to the project.
Choosing Your Sleepers
This is the first decision you should make to inform the rest of the project, and is the decision you should get right before making any purchases.
New softwood sleepers are easily the most available and cost effective option. Timber merchants and builders merchants have them for sale, and the cost in the UK is typically between £10 and £20. They are pressure treated to resist rot and will last 10–15 years in contact with soil. If you have a tight budget or are making your first raised bed, they represent a good option.
If appearance and longevity are important factors you consider when making purchases, oak sleepers are for you. With the ability to look visually pleasing even when weathered, oak sleepers are a nice option. With a price range of £30–£60, a full-size oak sleeper raises the price of a raised bed, but the investment is worth it, unlike typical temporary garden features.
If planning to grow vegetables, the use of reclaimed railway sleepers is strongly inadvisable. Creosote is used in the preservation of older reclaimed sleeper timber, and it may be partially leached. The use of reclaimed sleepers is a reasonable choice for ornamental bed borders, but the character and natural look of reclaimed timber is too hard to match to not utilize for your raised bed. The use of new timber you have a varying degree of certification is the only choice for edible raised beds.
Planning the Size
To ensure you are not required to step into the bed, the optimal width of a double sided raised bed is around 1.2 metres, and the optimal width of a single sided raised bed is around 600 to 700 mm.
Determining the number of sleepers required for your bed is prompted by the flexibility of the length. Standard sleepers are 2.4 metres long. The use of full sleepers, as a bed of 2.4 metres in length, will require no cutting. The use of your bed to be 1.8 metres, however, will require the cutting of every sleeper.
Height depends on the bending you’re willing to do and how deep your growing medium is. Most planting requires two rows of sleepers (about 300-400mm) and makes planting easier. Three rows creates a planting bed that is comfortably at a height to work at without kneeling. This is recommended for individuals who have a difficult time completing activities at low heights.
What You’ll Need
- Sleepers (determine how many per course from your dimensions, then multiply by the number of courses)
- Rebar or long timber stakes for fixing (One 600mm length of rebar for each corner and at about 1 metre intervals for a longer side)
- A drill with a long auger bit for rebar hole pre-drilling
- A club hammer or post driver for driving the rebar
- A spirit level
- Galvanised coach screws for fixing courses to each other (rebar will do the trick if you’re not going to do this)
- Landscaping fabric (optional, but recommended)
Building It
To begin, layout and mark the bed, then remove grass and the outermost layer of soil inside the perimeter. There is no need for a deep excavation (50-100mm) to provide a stable base for the bottom course and prevent lateral movement.
Lay the bottom course of your sleepers and check for level in both directions. This should be done before moving on, as making this level at the beginning saves a boatload of lateral adjustments in the long run. Depending on the terrain, consider packing the low side, or on the high side, further excavating.
At the corners, overlap the sleepers like running bond rather than butting them end to end. In this layout, the corner of one course has a sleeper running north-south, and the course above has a sleeper running east-west, overlapping the one below. This layout adds rigidity to the corner without metal brackets.
After constructing the first course of walls, drill anchors into the corners and the midpoints of the long sides. After drilling, drive first a rebar, and then a mesh of, anchors into the ground below to secure the walls. Drilling and driving anchors can be tiring and laborious, given certain ground conditions. As an alternative to a hammer, use a post driver. Portable drill rigs can also speed up the operation.
Lay subsequent courses with the joints staggered; do not shift the vertical joints between courses, as this creates and perpetuates a weak line. Secure each course to the course below with bolts or rebar, but leave enough space to drive anchors through to the ground.
The internal walls should be insulated with landscaping fabric. It will reduce the rate at which moisture is absorbed thereby, increasing the period of decay the sleepers are typically subjected to. It will also control, to an extent, the flow of soil through the walls.
For general flower beds, an equal ratio of garden compost and topsoil makes a great mixture and combination. For veggie beds, an even richer mixture that includes an equal ratio of topsoil, garden compost, and quality composted manure can make a noticeable difference. It is much cheaper to have bulk purchases of topsoil and composted manure separately than to buy a store brand composted manure for raised bed planters.
Fill the bed about up to 50 mm from the top to account for any settling and to fill for any overflow during watering. You can expect the bed to settle anywhere from 10-15% during the first few months, and topping it off with compost the next spring is typically advised and expected.
With the conditions that raised sleeper beds offer, they work for any kind of planting. However, some spirit the conditions for optimal growth. For veggie beds, raised beds with a deep mixture that allows for draining help root veggies that otherwise struggle with compact ground. Planting bulbs to the raised beds for a mid to late fall planting is a great option as they root up quickly with Dri Drain.
The conditions for the raised beds with regard to their placement next to ground level design and ground level decking or paving varies. Planting a mixture of some of allium, salvia, and ornamental grass for a 400mm raised bed is a more interesting design from ground level than a ground level bed with the same plants.
Leave a Reply