Sentence:  It was Digory who had the bright idea of eating four each and planting the ninth; for, as he said, "if the bar off the lamp-post turned into a little light-tree, why shouldn't this turn into a toffee-tree?" So they <WSD>dibbled</WSD> a small hole in the turf and buried the piece of toffee. 
Meaning of the word marked with <WSD> tags:  To make holes or plant seeds using, or as if using, a dibble.