Now that you have got our raised bed set up and ready to go, the next step is to add the planting medium.
Fill the raised bed with a layer of rubble for drainage and then cover the rubble with a layer of old turfs with the grass side downwards then top up the rest of the bed with good quality soil or compost. With really large raised beds you may wish to use a filler material but there are a couple of things you should keep in mind.
- Nitrogen depletion
If you use organic material as a filler it will decompose so you will have to top the bed up from time to time. The other problem with using organic material as a filler is that it uses nitrogen as it breaks down so you need to ensure that you add plenty of manure to compensate.
This is what you will need to plant up one of our 120x120x22cm raised beds once you have put in a layer of rubble and turf.
Raised bed Quanties and ingredients:
- 225 litres of garden soil.
- 225 litres of peat moss.
- A 25-kg bag of 16-20-10 fertilizer. This contains 4 kg of nitrogen, 5kg of phosphorus and 2.5kg of potash. This is a complete garden fertilizer, without one of these ingredients it is not a complete fertilizer.
- Place the peat in the middle of the raised bed and sprinkle a litre of garden lime over it. Mix the moss and lime together then smooth it evenly over the raised bed. Moss is acidic while lime is alkaline hence mixing them together helps balance the PH.
- Pour a litre of fetilizer over the moss lime mix.
- Now add your garden soil and rake it level. Then sprinkle about another half litre of fertilizer over the surface of the raised bed. Over time you will be adding grass clippings and other organic matter to your raised bed, enriching the soil, improving the quality of the soil more and more as time progresses.