Since water drains more quickly in raised beds, there is less of an issue with soil pooling nutrients or breeding disease. Raised garden beds have better control over the type of soil planted since you are not planting directly into the ground. Raised gardens make it easier to plant and maintain your crop. You can make them with wood and it is an easy DIY project that will elevate your garden in just a weekend.
Choosing the Right Timber
Opt for pressure-treated softwood, which is long-lasting and rot-resistant. Railway sleepers are loved for their chunky looks and durability but to prevent harmful chemicals leaching from old railway sleepers treated with creosote, avoid their use in a garden.
Untreated hardwood such as oak or cedar is naturally rot-resistant for organic gardeners and they avoid the need to add chemical treatment, however they are much more expensive. If using timber, make sure the material used is at least 25mm thick to resist pressure from soil. For Timber Merchants Southampton, visit www.timbco.co.uk/
Planning Your Bed
Perfect size: 1.2m wide (enabling you to get to the middle from both sides), any length that will fit in your space & for most veggies and flowers, a depth of 300-450mm. Root vegetables, such as carrots and parsnips do well in deeper beds. Place beds in sunny locations with at least access on two sides.
Materials You’ll Need
Corner posts (75mm x 75 mm) must all be cut to your required height plus a minimum of an extra 200 millimeters which will anchor the bed into the ground. Timber planks for sides, galvanised screws or coach bolts, a spirit level, mallet, or post driver.
Construction Steps
If you drive corner posts 200mm into the ground, make sure they are level and square. Affix your lower layer of planks to the posts with some galvanised screws and stand back to check it all is square. Keep adding layers of planks, staggering joints if using multiple pieces per side. Mid span supports are required for beds over 300mm high to resist bowing under soil pressure.
Finishing Touches
Lay landscape fabric on top of the bed base so weeds aren’t able to grow up through it but water can still easily drain away. No lining the sides – wood needs to breathe. Top up with good-quality topsoil mixed well with compost, and leave 50mm from the rim to avoid soil spilling over edges during watering.
Maintenance Tips
Annually check for rot or damage, especially where high moisture from the ground level is present. Untreated timber should be treated every two to three years. Good treated-timber beds ought to last maybe 10-15 years, hardwood probably more.