Super Cool Tomatoes

Yes, I know: It looks awful. But I like it. No I don't - But does it really matter if it works?

Of course, I cannot yet answer that in the affirmative - it is far too early - and the summer has suddenly disappeared. But we should soon find out. I was so convinced it would actually work that I did both pots, instead of leaving one as a control.

In case you haven't yet guessed its purpose, can I just say that it is not so I can admire myself as I do the watering. No. The idea is to keep the compost temperatures super cool in hot weather. Do you remember that?

Roots need far more oxygen as the temperatures rise. And because more carbon dioxide is given off by respiration in the soil, the situation can become serious and impede growth.

But water loss also increases dramatically with temperature. Keeping things cooler conserves it.

The scrumpled newspapers on the top should allow air and water passage, whilst providing insulation. And aluminium foil is a great reflector, thus evening out the diurnal (day and night) temperatures. Brilliant. I really surpass and amaze myself at times.

But, seriously, it is quite common to find hot sun literally boiling the roots of plants kept in black plastic pots. Dark colours absorb far more heat. And if white pots (these are not too good because they allow light to get to the roots) lower the compost temperatures by about 4 deg C compared with normal colours, I cannot see how this could fail.

Clay pots are good for keeping plants cooler, but need more watering.