Boys and girls of all ages should have separate school buildings, the Rebbe told Rabbi Mottel Altein, since children are so impressionable like a young tree.
“A person is likened to a tree,” the Rebbe told Reb Mottel Altein a”h in yechidus.
“If a dent is made in an aged tree, it will heal. The trunk will straighten itself out and return to its original state.
“However, a young tree is different. An imprint on the roots of a young sprout last forever — crooked for life.
“Similarly, for a child, even an experience in kindergarten leaves a lasting impression. Therefore, it is so imperative that boys and girls schools are separated, in different buildings, even from a young age.”
(Schurder Teshurah, Adar 5767)
From The Weekly Farbrengen by Merkaz Anash