So many people are scared to be too rough when planting and they plant so precisely and carefully the plant pops out of the ground when a heavy rain comes. So what is scarification, no its not when you open your bank balance, to your horror! No, its the systematic cutting of roots.
When you plant a tree or shrub usually the plant will be a bit pot bound, that means the roots have started to curve around the shape of the pot with no where to go. If you leave your plant or tree in this condition the roots will continue to wined round and round and never spread into the new soil. Some trees will strangle themselves to death with their own root after years of coiling around in the hole you dug.
How to Scarify
Now for the violent part! Take out your trusty knife when planting and large shrub or tree or use a sharp shovel and cut small portions of the root ball all over. Don't stab and stab the root ball to death like you would your father-in-law, just kidding! You basically want to loosen the root ball up a bit and create some beneficial injuries. Everywhere you have cut new roots will spring forth in every direction allowing the plant to become established more quickly in its new environment.
Smaller Annuals and Herbaceous Plants
When planing annual and smaller more herbaceous plants scarification can be done with your hands. Gently disturb the root ball just a bit so the new plants meristematic tissues are stimulate to begin repairing and growing. Meristematic cells are the rapidly growing areas of your plants like the root tips and buds. Like in life and bit of stress and competition creates growth so too a bit of shake up with your plants.
Make sure when repotting a plant that you only increase the size of the pot by about 10-20% in size. If you increase the soil promotions to greatly the soil we hold water and can mildew and spoil. Also, the plant received no benefit from a huge pot.
Next time you plant take out just a bit of your frustration and your new trees and shrubs will reward you for it.