[Spr0ut]

I recently tried just hanging a strip of foil down one side of the window and I am impressed by how well this works to maximise light to plants in the window, so I am busy making foil cards for the windows.

Do you take the cards down at night? I am thinking they might trap the plants in cold air between the card and the window glass? We often say don't close the curtains on tender plants because it traps them in a cold spot overnight.

 - and could I cover the cards in clear polythene to preserve the foil from snagging and scratches or would that stop the foil from reflecting as well?

[JayG]

I just use the aluminium foil on its own, scrunched round the pots as necessary to hold in place, but keeping the reflective side as smooth as possible. I rely on the double glazing to minimise the temperature drop at night, but I don't drop the blinds behind them.

If you don't have double glazing, you could try placing your cards on the window side at night to shield from the cold and also reflect room warmth back onto the plants.

Wouldn't go to the trouble of protecting with polythene - its bound to absorb some light and it could yellow or otherwise degrade quite quickly in sunlight.