I have planted a lot (thousands) of Amaranthus tricolour perfecta to harvest the leaves for including in commercial salads. The early sown ones are growing well but only about 1% are bright colours, the rest are rather dull.

The crop sown a month later from the same seed is a blaze of vibrant colours...every one.

I have cut back the dull ones in the hope that new growth may develope brighter colours. I was wondering whether increased potash might help. These are all in containers in a glasshouse.

Any ideas would be appreciated.

Glenn