Monday, March 22, 2010

The heat is on

The walls of walled gardens can sometimes hide a secret. Sometimes, as well as providing shelter, they can also give out heat. The clue is in the chimneys that line the top of the wall. The hollow walls act as flues, drawing heat up the wall and venting at the top. This would speed up flowering and fruiting, and protect against frosts.

The photo below shows several bricks pulled out; soot can still be found in the flues, from the fires that were lit at the back of the wall.

This photo (below) shows a rather utilitarian chimney on top of the heated wall in the walled vegetable garden.
Of course, the gentry couldn't possibly put up with the sight of such workaday stacks - it might offend their delicate sensibilities. So those walls that were heated in areas where the lords and ladies might stroll had to be disguised. As rather ornate-looking urns. Those were the days.

For detailed diagrams on how some of the heating systems used in glasshouses, here's a link to a e-book on The Early Heating of Glasshouses.


Anonymous said...

Thanks Happy! I had no idea about the walls being heated over there. We thought it was simply their very existence as wind blocks that kept the gardens warmer. Love those toppers, whatever shape they are!

chaiselongue said...

Fascinating, and I love the idea that the toffs couldn't bear to see chimneys! The walls themselves would have retained and given out heat, too, in summer. We notice that here - walls that face the sun in summer feel hot all night, even thought they're old and getting on for a metre thick.

Jo said...

I didn't know that they heated the walls, that's fascinating. I will be looking out for the clues when I next visit a walled garden.

Tim said...

What a great post! Thank you!

easygardener said...

I must say the last photo made me laugh out loud. Those toffs - so delicate and refined. I'm surprised any survived the loss of their natural habitat :-)

HappyMouffetard said...

Hi Frances, yes, the walls are very important in blocking wind, but the heated walls protect the fruit growing directly against them. Interestingly, the west wall of the walled garden was lower than the others - this was suggested to be because the winter sun is lower, it allows more afternoon winter sun into the garden. Walled gardens are fascinating.

Chaiselongue - yes, I'm sure that was a factor too in the summer.

Jo - it's amazing the things you don't notice until someone points them out to you. I can't wait to visit another garden so I can see what things I can notice know I have a little bit of knowledge.

Tim - you're welcome. Thanks for visiting.

EG :-D I think they may be an endangered species.