Cae Non

Building Raised Beds

The year is flying round at quite a pace, and it has been quite a while since I posted updates with progress on the herb garden. But we haven’t been idle…

Unfortunately, due to ongoing renovation work at our house, we have rather a lot of reclaimed timber at the moment. It has been absolutely ideal for making raised beds for my herbs, and so far, I have made 4 largish (7 x 3′) beds that are about 18” deep. As it happens, the hard work was not in building them, but filling them with soil; each bed took about 25 sacks of topsoil to fill. As the soil at Cae Non is so heavy with clay, we have bought in a ton of topsoil, and these beds have used most of it.

Planting the first set of herbs for 2013

The soil is enriched with some good quality topsoil/compost we found on site, this has generally been used to top the beds as it is of better quality than the topsoil we bought in! I have also added layers of grass clippings to try to introduce some organic matter into the soil. The one different thing that I have done with these beds that is entirely new to me is the addition of bio-char. Bio-char is the introduction of small charcoal pieces into soil – it serves two purposes: firstly it locks up carbon in the soil in a very stable form that is stable for thousands of years, thus sequestering carbon. But it is the second remarkable property of bio-char that we are interested in in these beds: It greatly enriches the soil. It improves drainage as it is porous, acting as a growth media for beneficial bacteria that will put life back into the soil. It will also directly fertilise the soil too as it is rich in potash and some other minerals. This idea originates with the South American tribes who use this process to make what is known as ‘Terra Preta’ – the foundation of their crop cultivation for millennia. For those interested, more information is available here on Wikipedia.

The first bed to be constructed had the most bio-char in it as I’ve been enriching it for the longest time: It has also grown the best herbs as you can see from the photo below:

First raised beds finished and in bloom!

The planting list for the four raised beds so far is:

Bed 1:
Eschscholzia californica – Californian poppy
Matricaria recutita – Chamomille
Achillea milefolium – Yarrow

Bed 2:
Borago officinalis – Borage
Silybum marianum – Milk Thistle

Bed 3:
Althea officinalis – Mallow
Leonurus cardiaca – Motherwort
Digitalis purpurea – Purple Foxglove
Arctium lappa – Burdock

Bed 4:Valeriana officinalis – Valerian
Verbena officinalis – Vervain
Inula helenium – Elecampane

Many more raised beds are planned, but this is a good start for this summer, and we should soon be reaping the harvest of some of the herbs planted this year!