Now isn't this strange?????

We have just realised - we put in three small black pots with two watermelon seeds in each, and two toilet rolls with one seed in each. They had exactly the same soil mix, fertiliser etc.

The ones in the black pots are rangy and weaker. The ones in the toilet rolls are stronger, bigger cotyledons, and overall much healthier.

All we can think is that maybe the black pots absorbed a little bit of sun (not much available) and got hotter. The two lots of pots have been together since planted, not even a few inches apart.

But to make such a difference? Any suggestions welcome.

We are off to design some carefully planned experiments.