Springtime is the time during which trimming has the biggest effect on your tree. This Crataegus was trimmed back to two leaves as soon as the stems started to turn purple. This stimulates backbudding, and bifurbication of this years’ growth. All in order to create a denser canopy.
Depending of course, on the species. Trim the wrong one and it will be set back a year. Japanese Maples are not pruned that soon, but a Trident can be, same applies to Pines. Pinch a White Pine and that is the end of growth for the year. Black Pines are multi flush so can be pinched.
Creatagus? There is no such tree.
thank you.