They need to thicken out and grow more than that before you plant them out.
They should be outdoors now or in a cooler area indoors. Are they growing
well as a weak liquid feed may help in case the compost is out of umph! Thin
pencil thickness about 6 inches high is how I transplant them, anything
smaller never seems to catch up, at least that's how it seems

Alan Holmes wrote:
: Some of the leek seedlings are about an inch high.
:
: What do i do with them?
:
: Should I leave them longer or try to transplant them now?
:
: Alan