Growing doesn't have to mean large spaces and this year our #foodchallenge will explore past ideas of growing vs modern ways of growing. As we slide into the start of the growing year we want to look at two ways of growing in the cold months. First we're looking at the Victorian hotbed, for those of you who have never come across a hotbed, here's how to make one.
You will need a deep container, in our case we are using some old floor beams cut to length. They aren't nailed together, in fact we spent the morning taking coach screws out of them as students from the Hopwood garden wheeled down fresh manure - the kind that still steams on a cold day when dug into - to fill the container. All you need to know with fresh manure is that YOU CANNOT DIRECT SOW SEEDS INTO IT. Sorry, did we yell? What we meant to say is, YOU CANNOT DIRECT SOW SEEDS INTO IT, PLEASE. You will simply bake your seeds. Why fresh manure?
As manure rots it generates heat, lots of heat but it can never be grown in or used fresh around plants for fear of E.coli O157 and if human waste (yes, you can use it, referred to gong in old gardening and farming books), salmonella. What we want in this bed is the heat. This means we can't leave any air pockets, because these could lead to fires and in some very rare cases, manure explosions as the gases build and fill the gaps. So, always tread down a hot bed, you can see a student doing the manure dance above, yes it stank and yes he was scared of falling into it.
You then cap the fresh manure, which is around three to four feet deep with three inches of well rotted manure, and then cap with around three to four inches of compost. This is soil that is safe to grow in and of a crumbly tilth. You can see the finished soil level below. There is a bamboo cane in the hot bed so students can see how hot the cane is when pulled out. Try this at home.
This bottom heat will get the seeds away but how will it fair against a modern heated bench? Over the next few days we will sow seed trays in heated propagators and we can follow the journey of a hot bed vs a heated bench, and you can see what can be achieved on a windowsill or in a larger space.