Lavender's Blue dilly dilly
Ring a ring a roses
How many gentle flowers grow in an English country garden?
I like the flowers, I love the daffodils
Life is but a melancholy flower (Life is butter melon cauliflower)
The oak and the ash and the bonny ivy tree... (A North country maid up to London had strayed...)
Land of the silver birch (we used to sing that in guides - I think it's a Canadian song, we sang it in a round)
There's another one which I know in German and French and I'm sure there's an English version but it escapes me for the moment: French: "Vent frais, vent du matin, vent qui souffle au sommet des grands pins.."