Raised and framed beds: a quick guide to gardening in beds

Raised and framed beds: a quick guide to gardening in beds

There has been a real boom in raised beds in the last few years. You see them everywhere. Often even in old cottage gardens, which offer the best conditions for gardening in the ground, i.e. fertile garden soil that has evolved over many years. A raised bed has lots of advantages. A tried-and-tested alternative that is less well known, but much cheaper and easier to fill, are slightly raised framed beds.

When to use raised beds

  • Sealed surfaces or ground contaminated with pollutants. This is often the case in urban open spaces in particular.
  • For wheelchair users or people who find it difficult to bend down.
  • Heavily compacted ground, for example after building work.
  • In a garden where a lot of shrub cuttings are produced. This and other garden "waste" can be incorporated into a raised bed by filling it using the Hügelkultur method: shrub cuttings, leaves, grass sods, half-rotted compost, with garden soil on top. These beds develop their own in-built nutrient store over 3-4 years and act as underfloor heating, significantly extending the harvesting season for vegetables. These raised beds are comparable to planted compost heaps and are especially suited to strong uptakers (squash, tomatoes, aubergines and so on).
  • In small gardens where clever use of space is vital.
  • Raised beds also perform well in sloping gardens, where they can be installed so they sit on the slope like terraces.

Filling a raised bed using the Hügelkultur method
This filling is only suitable if your garden produces lots of material that you can use in this way. These materials rot and therefore the earth shrinks, so the bed needs to be refilled every 3 - 5 years. Filling (for a 70 cm high raised bed): the bottom layer is approx. 40 cm of branches, followed by a non-woven layer and then 10 cm of turf or clippings, straw and mixed garden waste, then 15 cm of leaves, 10 cm of rough compost and 20 cm of garden soil mixed with 20% mature fine compost. For a higher raised bed, increase the depth of the individual layers increased proportionally. For a lower raised bed, reduce the layer of branches to just 20 cm.

Filling a raised bed for long-term use
If you do not want to refill your raised bed every few years, use the trough system: the bottom layer is approx. 20 cm of ideally lava (which holds water) for drainage. You then spread a non-woven layer over this (pulled up almost to the level of the soil) and add trough soil. This has a high mineral content (pumice, lava, expanded slate, brick chippings) and therefore does not shrink. You will most likely also have to add fertiliser if you want to grow vegetables.

The correct dimensions for a raised bed
The most comfortable working height is hip height, i.e. 70-100 cm. The length is variable and is determined by the available space. The ideal width is chosen so that the bed is easy to work from both sides: 2x arm length, i.e. 140-160 cm.

Framed bed: a cheap and tried-and-tested alternative to raised beds
Many gardens have beds that have already been used as vegetables beds, but are just not very productive. Or a piece of lawn that could be turned into a vegetable bed. For areas like these, and for people who have good mobility and can bend over, I recommend framed beds: these are simple constructions made of wood or metal (see photos below) that are placed on the ground like a frame. You can buy these frames or make them yourself. They should be around 40 cm high and sunk approx. 10 cm into the ground. You need much less earth to fill them than a raised bed, so they provide a way of creating very productive cultivation areas for vegetables with minimal effort. The ground underneath simply needs to be loosened slightly with a pitchfork.

Andrea Heistinger
VIKING gardening expert