We have two Gingkos, one about 120 years old and one about fifty.  Thankfully, both are males, so no fruit.  They are lovely trees, though the young one is too big for its space.  They are quite hardy in this area, but they have some quirks….  In the fall, if the temperature drops to a certain point, they drop ALL their leaves ALL at once (as in less than eight hours).  It doesn’t matter if they are still green or have turned gold, they will drop.

As it turns out, it would seem that 25 F is that temperature.  At least, yesterday both had essentially all their leaves.  Last night hit 25 F; this morning there was a gentle, steady patter of falling leaves.  By noon they were bare and the ground was carpeted several inches deep in leaves.  This year about eighty percent had turned, so it is a mostly gold carpet; but they are still a bit green and a bit soggy.  I will pick them up tomorrow.

The other quirk is that gingko leaves do not decompose easily.  Fallen leaves, if they have turned gold and dried out, can last several years in dry shade.  They are hydrophobic, even in a watered compost pile, they will form clumps that are literally bone dry despite being surrounded by soggy material.  If they are green when they fall, they will decompose…..much like banana peels will…. (i.e. suffocating slime) this is not desirable!  We pick them up, separated from the other leaves and create a pile which just sort of sits there.  We try to pick up only about half of the oak/maple/magnolia/beech leaves, leaving the rest as mulch; but we try to collect essentially all of the gingko leaves.